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Cation-chloride cotransporters in neuronal development, plasticity and disease

Key Points

  • The regulation of intraneuronal Cl by cation-chloride cotransporters (CCCs) has a key role in determining the reversal potential (EGABA) and driving force (DFGABA) of GABAA mediated currents and thereby controls the cellular and network-level actions of GABA.

  • Changes in the spatiotemporal patterns of the expression of functional CCCs and consequent changes in Cl regulation underlie major quantitative and qualitative changes in GABAergic signalling that are known to take place during neuronal development, plasticity and disease.

  • GABAergic signalling exhibits ionic plasticity, which is based on short-term and long-term changes in the value of EGABA that are brought about by fast activity-dependent net ion fluxes as well as transcriptional and post-translational modifications of CCCs.

  • Most of the basic effects of CCCs on GABAAR signalling also apply to the glycinergic system, and therefore CCCs are important in both the brain and the spinal cord.

  • Recent evidence indicates that CCCs also have unexpected roles in neurons that go beyond their 'canonical' ion-transport functions. Notably, K+–Cl cotransporter 2 (KCC2), the main neuronal Cl-extruding CCC isoform, has an important morphogenic role in the formation of cortical dendritic spines.

  • In addition to our increasing understanding of the roles of CCCs in the fundamental machinery underlying neuronal signalling and structure, their diverse roles in neurological diseases have attracted an increasing amount of attention in translational and clinical work. Emerging pharmacological strategies designed for combating various neurological disorders, including epilepsy and chronic pain, are based on targeting CCCs.

Abstract

Electrical activity in neurons requires a seamless functional coupling between plasmalemmal ion channels and ion transporters. Although ion channels have been studied intensively for several decades, research on ion transporters is in its infancy. In recent years, it has become evident that one family of ion transporters, cation-chloride cotransporters (CCCs), and in particular K+–Cl cotransporter 2 (KCC2), have seminal roles in shaping GABAergic signalling and neuronal connectivity. Studying the functions of these transporters may lead to major paradigm shifts in our understanding of the mechanisms underlying brain development and plasticity in health and disease.

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Figure 1: Developmental expression profiles, functions and secondary structures of CCCs.
Figure 2: Mechanisms of ionic plasticity and their temporal domains.
Figure 3: Cation-chloride cotransporters in pain.

References

  1. Kaila, K. Ionic basis of GABAA receptor channel function in the nervous system. Prog. Neurobiol. 42, 489–537 (1994).

    CAS  PubMed  Google Scholar 

  2. Rivera, C. et al. The K+/Cl co-transporter KCC2 renders GABA hyperpolarizing during neuronal maturation. Nature 397, 251–255 (1999). This was the first study to demonstrate the causal role of KCC2 upregulation in the development of hyperpolarizing inhibition.

    CAS  PubMed  Google Scholar 

  3. Stein, V., Hermans-Borgmeyer, I., Jentsch, T. J. & Hübner, C. A. Expression of the KCl cotransporter KCC2 parallels neuronal maturation and the emergence of low intracellular chloride. J. Comp. Neurol. 468, 57–64 (2004).

    CAS  PubMed  Google Scholar 

  4. Zhu, L., Lovinger, D. & Delpire, E. Cortical neurons lacking KCC2 expression show impaired regulation of intracellular chloride. J. Neurophysiol. 93, 1557–1568 (2005).

    CAS  PubMed  Google Scholar 

  5. Seja, P. et al. Raising cytosolic Cl in cerebellar granule cells affects their excitability and vestibulo-ocular learning. EMBO J. 31, 1217–1230 (2012). This elegant study used cell-specific genetic targeting of KCC2 and KCC3 to clarify their contribution to Cl regulation and spine morphology in the mature cerebellar cortex.

    CAS  PubMed  PubMed Central  Google Scholar 

  6. Blaesse, P., Airaksinen, M. S., Rivera, C. & Kaila, K. Cation-chloride cotransporters and neuronal function. Neuron 61, 820–838 (2009).

    CAS  PubMed  Google Scholar 

  7. Russell, J. M. Sodium-potassium-chloride cotransport. Physiol. Rev. 80, 211–276 (2000).

    CAS  PubMed  Google Scholar 

  8. Achilles, K. et al. Kinetic properties of Cl uptake mediated by Na+-dependent K+-2Cl cotransport in immature rat neocortical neurons. J. Neurosci. 27, 8616–8627 (2007). The authors show how to rigorously quantify NKCC1-mediated Cl uptake using an electrophysiological approach.

    CAS  PubMed  PubMed Central  Google Scholar 

  9. Ben-Ari, Y., Gaiarsa, J. L., Tyzio, R. & Khazipov, R. GABA: a pioneer transmitter that excites immature neurons and generates primitive oscillations. Physiol. Rev. 87, 1215–1284 (2007).

    CAS  PubMed  Google Scholar 

  10. Sipilä, S. T. et al. Compensatory enhancement of intrinsic spiking upon NKCC1 disruption in neonatal hippocampus. J. Neurosci. 29, 6982–6988 (2009).

    PubMed  PubMed Central  Google Scholar 

  11. Khirug, S. et al. A single seizure episode leads to rapid functional activation of KCC2 in the neonatal rat hippocampus. J. Neurosci. 30, 12028–12035 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  12. Payne, J. A. in Physiology and Pathology of Chloride Transporters and Channels in the Nervous System (eds Alvarez-Leefmans, F. J. & Delpire, E.) 333–356 (Academic Press, 2009).

    Google Scholar 

  13. Hansen, A. J. Effect of anoxia on ion distribution in the brain. Physiol. Rev. 65, 101–148 (1985).

    CAS  PubMed  Google Scholar 

  14. Buzsaki, G., Kaila, K. & Raichle, M. Inhibition and brain work. Neuron 56, 771–783 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Kaila, K., Ruusuvuori, E., Seja, P., Voipio, J. & Puskarjov, M. GABA actions and ionic plasticity in epilepsy. Curr. Opin. Neurobiol. 26, 34–41 (2014).

    CAS  PubMed  Google Scholar 

  16. Nabekura, J. et al. Reduction of KCC2 expression and GABAA receptor-mediated excitation after in vivo axonal injury. J. Neurosci. 22, 4412–4417 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  17. Rivera, C. et al. BDNF-induced TrkB activation down-regulates the K+-Cl cotransporter KCC2 and impairs neuronal Cl extrusion. J. Cell Biol. 159, 747–752 (2002).

    CAS  PubMed  PubMed Central  Google Scholar 

  18. Coull, J. A. et al. Trans-synaptic shift in anion gradient in spinal lamina I neurons as a mechanism of neuropathic pain. Nature 424, 938–942 (2003). The first paper to clearly delineate a role for loss of KCC2 function in the dorsal horn in the generation of neuropathic pain.

    CAS  PubMed  Google Scholar 

  19. Jin, X., Huguenard, J. R. & Prince, D. A. Impaired Cl extrusion in layer V pyramidal neurons of chronically injured epileptogenic neocortex. J. Neurophysiol. 93, 2117–2126 (2005). This study demonstrates that measurements of E GABA obtained in the absence of experimental Cl loading are not necessarily sufficient to prove compromised Cl extrusion following neuronal damage.

    CAS  PubMed  Google Scholar 

  20. Pathak, H. R. et al. Disrupted dentate granule cell chloride regulation enhances synaptic excitability during development of temporal lobe epilepsy. J. Neurosci. 27, 14012–14022 (2007). A seminal study on the erosion of inhibition and loss of the dentate 'seizure barrier' following seizure-induced downregulation of KCC2.

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Boulenguez, P. et al. Down-regulation of the potassium-chloride cotransporter KCC2 contributes to spasticity after spinal cord injury. Nature Med. 16, 302–307 (2010).

    CAS  PubMed  Google Scholar 

  22. Jaenisch, N., Witte, O. W. & Frahm, C. Downregulation of potassium chloride cotransporter KCC2 after transient focal cerebral ischemia. Stroke 41, e151–e159 (2010).

    CAS  PubMed  Google Scholar 

  23. Zhou, H. Y. et al. N-methyl-D-aspartate receptor- and calpain-mediated proteolytic cleavage of K+-Cl cotransporter-2 impairs spinal chloride homeostasis in neuropathic pain. J. Biol. Chem. 287, 33853–33864 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Clarkson, A. N., Huang, B. S., Macisaac, S. E., Mody, I. & Carmichael, S. T. Reducing excessive GABA-mediated tonic inhibition promotes functional recovery after stroke. Nature 468, 305–309 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Karpova, N. N. et al. Fear erasure in mice requires synergy between antidepressant drugs and extinction training. Science 334, 1731–1734 (2011). This study opens up a novel field of research for studies on CCC functions in so-called induced plasticity brought about by antidepressant drugs.

    CAS  PubMed  PubMed Central  Google Scholar 

  26. Rinke, I., Artmann, J. & Stein, V. ClC-2 voltage-gated channels constitute part of the background conductance and assist chloride extrusion. J. Neurosci. 30, 4776–4786 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  27. Ratte, S. & Prescott, S. A. ClC-2 channels regulate neuronal excitability, not intracellular chloride levels. J. Neurosci. 31, 15838–15843 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  28. Li, H. et al. KCC2 interacts with the dendritic cytoskeleton to promote spine development. Neuron 56, 1019–1033 (2007). This study was the first to show an ion-transport-independent role of KCC2 in cortical dendritic spines.

    CAS  PubMed  Google Scholar 

  29. Gauvain, G. et al. The neuronal K-Cl cotransporter KCC2 influences postsynaptic AMPA receptor content and lateral diffusion in dendritic spines. Proc. Natl Acad. Sci. USA 108, 15474–15479 (2011). This study demonstrated that KCC2 regulates the efficacy of glutamatergic synapses by constraining AMPA receptors in spines.

    CAS  PubMed  PubMed Central  Google Scholar 

  30. Fiumelli, H. et al. An ion transport-independent role for the cation-chloride cotransporter KCC2 in dendritic spinogenesis in vivo. Cereb. Cortex 23, 378–388 (2013).

    PubMed  Google Scholar 

  31. Puskarjov, M. et al. A variant of KCC2 from patients with febrile seizures impairs neuronal Cl extrusion and dendritic spine formation. EMBO Rep. 15, 723–729 (2014). This work was the first to identify and functionally characterize a human SLC12A5 disease mutation, which is a candidate susceptibility gene for febrile seizures.

    CAS  PubMed  PubMed Central  Google Scholar 

  32. Blaesse, P. & Schmidt, T. K-Cl cotransporter KCC2 — a moonlighting protein in excitatory and inhibitory synapse development and function. Pflugers Arch. http://dx.doi.org/10.1007/s00424-014-1547-6 (2014).

  33. Gamba, G. Molecular physiology and pathophysiology of electroneutral cation-chloride cotransporters. Physiol. Rev. 85, 423–493 (2005).

    CAS  PubMed  Google Scholar 

  34. Price, T. J., Cervero, F. & De Koninck, Y. Role of cation-chloride-cotransporters (CCC) in pain and hyperalgesia. Curr. Top. Med. Chem. 5, 547–555 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. De Koninck, Y. Altered chloride homeostasis in neurological disorders: a new target. Curr. Opin. Pharmacol. 7, 93–99 (2007).

    CAS  PubMed  Google Scholar 

  36. Kahle, K. T. et al. Roles of the cation-chloride cotransporters in neurological disease. Nature Clin. Pract. Neurol. 4, 490–503 (2008).

    CAS  Google Scholar 

  37. Hyde, T. M. et al. Expression of GABA signaling molecules KCC2, NKCC1, and GAD1 in cortical development and schizophrenia. J. Neurosci. 31, 11088–11095 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  38. Kim, J. Y. et al. Interplay between DISC1 and GABA signaling regulates neurogenesis in mice and risk for schizophrenia. Cell 148, 1051–1064 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Tao, R. et al. Transcript-specific associations of SLC12A5 (KCC2) in human prefrontal cortex with development, schizophrenia, and affective disorders. J. Neurosci. 32, 5216–5222 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  40. Löscher, W., Puskarjov, M. & Kaila, K. Cation-chloride cotransporters NKCC1 and KCC2 as potential targets for novel antiepileptic and antiepileptogenic treatments. Neuropharmacology 69, 62–74 (2013).

    PubMed  Google Scholar 

  41. Puskarjov, M., Kahle, K. T., Ruusuvuori, E. & Kaila, K. Pharmacotherapeutic targeting of cation-chloride cotransporters in neonatal seizures. Epilepsia 55, 806–818 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  42. Payne, J. A. Molecular operation of the cation chloride cotransporters: ion binding and inhibitor interaction. Curr. Top. Membr. 70, 215–237 (2012).

    CAS  PubMed  Google Scholar 

  43. Warmuth, S., Zimmermann, I. & Dutzler, R. X-ray structure of the C-terminal domain of a prokaryotic cation-chloride cotransporter. Structure. 17, 538–546 (2009).

    CAS  PubMed  Google Scholar 

  44. Medina, I. et al. Current view on the functional regulation of the neuronal K-Cl cotransporter KCC2. Front. Cell. Neurosci. 8, 27 (2014).

    PubMed  PubMed Central  Google Scholar 

  45. Payne, J. A., Rivera, C., Voipio, J. & Kaila, K. Cation-chloride co-transporters in neuronal communication, development and trauma. Trends Neurosci. 26, 199–206 (2003).

    CAS  PubMed  Google Scholar 

  46. Gagnon, K. B. & Delpire, E. Physiology of SLC12 transporters: lessons from inherited human genetic mutations and genetically-engineered mouse knockouts. Am. J. Physiol. Cell Physiol. 304, C693–C714 (2013).

    PubMed  PubMed Central  Google Scholar 

  47. Inoue, W. & Bains, J. S. Beyond inhibition: GABA synapses tune the neuroendocrine stress axis. Bioessays 36, 561–569 (2014).

    CAS  PubMed  Google Scholar 

  48. Kim, Y. B. et al. GABAergic excitation of vasopressin neurons: possible mechanism underlying sodium-dependent hypertension. Circ. Res. 113, 1296–1307 (2013). This pioneering work shows that GABAergic inhibition is converted into NKCC1-dependent excitation of vasopressin-releasing hypothalamic neurons in a rat model of hypertension. This also implies that CCCs are promising drug targets for the treatment of hypertension.

    CAS  PubMed  Google Scholar 

  49. Gamba, G. et al. Molecular cloning, primary structure, and characterization of two members of the mammalian electroneutral sodium-(potassium)-chloride cotransporter family expressed in kidney. J. Biol. Chem. 269, 17713–17722 (1994).

    CAS  PubMed  Google Scholar 

  50. Clayton, G. H., Owens, G. C., Wolff, J. S. & Smith, R. L. Ontogeny of cation-Cl cotransporter expression in rat neocortex. Dev. Brain Res. 109, 281–292 (1998).

    CAS  Google Scholar 

  51. Lucas, O., Hilaire, C., Delpire, E. & Scamps, F. KCC3-dependent chloride extrusion in adult sensory neurons. Mol. Cell Neurosci. 50, 211–220 (2012).

    CAS  PubMed  Google Scholar 

  52. Mao, S. et al. Molecular and functional expression of cation-chloride cotransporters in dorsal root ganglion neurons during postnatal maturation. J. Neurophysiol. 108, 834–852 (2012).

    PubMed  PubMed Central  Google Scholar 

  53. Payne, J. A., Stevenson, T. J. & Donaldson, L. F. Molecular characterization of a putative K-Cl cotransporter in rat brain. A neuronal-specific isoform. J. Biol. Chem. 271, 16245–16252 (1996).

    CAS  PubMed  Google Scholar 

  54. Li, H., Tornberg, J., Kaila, K., Airaksinen, M. S. & Rivera, C. Patterns of cation-chloride cotransporter expression during embryonic rodent CNS development. Eur. J. Neurosci. 16, 2358–2370 (2002).

    PubMed  Google Scholar 

  55. Gagnon, K. B. & Di, F. M. A molecular analysis of the Na+-independent cation chloride cotransporters. Cell Physiol. Biochem. 32, 14–31 (2013).

    CAS  PubMed  Google Scholar 

  56. Le Rouzic, P. et al. KCC3 and KCC4 expression in rat adult forebrain. Brain Res. 1110, 39–45 (2006).

    CAS  PubMed  Google Scholar 

  57. Gagnon, K. B., Adragna, N. C., Fyffe, R. E. & Lauf, P. K. Characterization of glial cell K-Cl cotransport. Cell Physiol. Biochem. 20, 121–130 (2007).

    CAS  PubMed  Google Scholar 

  58. Uvarov, P. et al. A novel N-terminal isoform of the neuron-specific K-Cl cotransporter KCC2. J. Biol. Chem. 282, 30570–30576 (2007). KCC2b was identified as the main KCC2 splice variant, which is responsible for hyperpolarizing GABA actions.

    CAS  PubMed  Google Scholar 

  59. Uvarov, P. et al. Coexpression and heteromerization of two neuronal K-Cl cotransporter isoforms in neonatal brain. J. Biol. Chem. 284, 13696–13704 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  60. Gulacsi, A. et al. Cell type-specific differences in chloride-regulatory mechanisms and GABAA receptor-mediated inhibition in rat substantia nigra. J. Neurosci. 23, 8237–8246 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  61. Kanaka, C. et al. The differential expression patterns of messenger RNAs encoding K-Cl cotransporters (KCC1,2) and Na-K-2Cl cotransporter (NKCC1) in the rat nervous system. Neuroscience 104, 933–946 (2001).

    CAS  PubMed  Google Scholar 

  62. Bartho, P., Payne, J. A., Freund, T. F. & Acsady, L. Differential distribution of the KCl cotransporter KCC2 in thalamic relay and reticular nuclei. Eur. J. Neurosci. 20, 965–975 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  63. Sun, Y. G. et al. GABAergic synaptic transmission triggers action potentials in thalamic reticular nucleus neurons. J. Neurosci. 32, 7782–7790 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  64. Song, L. Y. et al. Molecular, functional, and genomic characterization of human KCC2, the neuronal K-Cl cotransporter. Mol. Brain Res. 103, 91–105 (2002).

    CAS  PubMed  Google Scholar 

  65. Horn, Z., Ringstedt, T., Blaesse, P., Kaila, K. & Herlenius, E. Premature expression of KCC2 in embryonic mice perturbs neural development by an ion transport-independent mechanism. Eur. J. Neurosci. 31, 2142–2155 (2010).

    PubMed  Google Scholar 

  66. Talos, D. M. et al. Altered inhibition in tuberous sclerosis and type IIb cortical dysplasia. Ann. Neurol. 71, 539–551 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  67. Wang, C. et al. Developmental changes in KCC1, KCC2, and NKCC1 mRNA expressions in the rat brain. Brain Res. Dev. Brain Res. 139, 59–66 (2002).

    CAS  PubMed  Google Scholar 

  68. Blaesse, P. et al. Oligomerization of KCC2 correlates with development of inhibitory neurotransmission. J. Neurosci. 26, 10407–10419 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  69. Balakrishnan, V. et al. Expression and function of chloride transporters during development of inhibitory neurotransmission in the auditory brainstem. J. Neurosci. 23, 4134–4145 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  70. Uvarov, P., Ludwig, A., Markkanen, M., Rivera, C. & Airaksinen, M. S. Upregulation of the neuron-specific K+/Cl cotransporter expression by transcription factor early growth response 4. J. Neurosci. 26, 13463–13473 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  71. Sun, C., Zhang, L. & Chen, G. An unexpected role of neuroligin-2 in regulating KCC2 and GABA functional switch. Mol. Brain 6, 23 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  72. Bayatti, N. et al. A molecular neuroanatomical study of the developing human neocortex from 8 to 17 postconceptional weeks revealing the early differentiation of the subplate and subventricular zone. Cereb. Cortex 18, 1536–1548 (2008).

    PubMed  Google Scholar 

  73. Hübner, C. A. et al. Disruption of KCC2 reveals an essential role of K-Cl cotransport already in early synaptic inhibition. Neuron 30, 515–524 (2001). The first paper on a full Slc12a5 -knockout mouse. The authors concluded that the perinatally lethal phenotype is attributable to lack of functional inhibition and consequent lack of central motor programmes, especially those sustaining breathing.

    PubMed  Google Scholar 

  74. Khalilov, I. et al. Enhanced synaptic activity and epileptiform events in the embryonic kcc2 deficient hippocampus. Front. Cell Neurosci. 5, 23 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  75. Erecinska, M., Cherian, S. & Silver, I. A. Energy metabolism in mammalian brain during development. Prog. Neurobiol. 73, 397–445 (2004).

    CAS  PubMed  Google Scholar 

  76. Vanhatalo, S. et al. Slow endogenous activity transients and developmental expression of K+-Cl cotransporter 2 in the immature human cortex. Eur. J. Neurosci. 22, 2799–2804 (2005).

    PubMed  Google Scholar 

  77. Robinson, S., Mikolaenko, I., Thompson, I., Cohen, M. L. & Goyal, M. Loss of cation-chloride cotransporter expression in preterm infants with white matter lesions: implications for the pathogenesis of epilepsy. J. Neuropathol. Exp. Neurol. 69, 565–572 (2010).

    CAS  PubMed  Google Scholar 

  78. Sedmak, G., Jovanov-Milosevic, N., Puskarjov, M., Kaila, K. & Judas, M. Expression patterns of K-Cl cotransporter KCC2 in the human fetal and adult brain. FENS Abstr. 2398 (2014).

  79. Dzhala, V. I. et al. NKCC1 transporter facilitates seizures in the developing brain. Nature Med. 11, 1205–1213 (2005).

    CAS  PubMed  Google Scholar 

  80. Karadsheh, M. F. & Delpire, E. Neuronal restrictive silencing element is found in the KCC2 gene: molecular basis for KCC2-specific expression in neurons. J. Neurophysiol. 85, 995–997 (2001).

    CAS  PubMed  Google Scholar 

  81. Uvarov, P., Pruunsild, P., Timmusk, T. & Airaksinen, M. S. Neuronal K+/Cl co-transporter (KCC2) transgenes lacking neurone restrictive silencer element recapitulate CNS neurone-specific expression and developmental up-regulation of endogenous KCC2 gene. J. Neurochem. 95, 1144–1155 (2005).

    CAS  PubMed  Google Scholar 

  82. Yeo, M., Berglund, K., Augustine, G. & Liedtke, W. Novel repression of Kcc2 transcription by REST-RE-1 controls developmental switch in neuronal chloride. J. Neurosci. 29, 14652–14662 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  83. Ludwig, A. et al. Early growth response 4 mediates BDNF induction of potassium chloride cotransporter 2 transcription. J. Neurosci. 31, 644–649 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  84. Goldberg, E. M. & Coulter, D. A. Mechanisms of epileptogenesis: a convergence on neural circuit dysfunction. Nature Rev. Neurosci. 14, 337–349 (2013).

    CAS  Google Scholar 

  85. Aguado, F. et al. BDNF regulates spontaneous correlated activity at early developmental stages by increasing synaptogenesis and expression of the K+/Cl co-transporter KCC2. Development 130, 1267–1280 (2003).

    CAS  PubMed  Google Scholar 

  86. Markkanen, M., Uvarov, P. & Airaksinen, M. S. Role of upstream stimulating factors in the transcriptional regulation of the neuron-specific K-Cl cotransporter KCC2. Brain Res. 1236, 8–15 (2008).

    CAS  PubMed  Google Scholar 

  87. Galanopoulou, A. S. Sexually dimorphic expression of KCC2 and GABA function. Epilepsy Res. 80, 99–113 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  88. Kight, K. E. & McCarthy, M. M. Using sex differences in the developing brain to identify nodes of influence for seizure susceptibility and epileptogenesis. Neurobiol. Dis. http://dx.doi.org/10.1016/j.nbd.2014.05.027 (2014).

  89. Ganguly, K., Schinder, A. F., Wong, S. T. & Poo, M. M. GABA itself promotes the developmental switch of neuronal GABAergic responses from excitation to inhibition. Cell 105, 521–532 (2001).

    CAS  PubMed  Google Scholar 

  90. Ludwig, A., Li, H., Saarma, M., Kaila, K. & Rivera, C. Developmental up-regulation of KCC2 in the absence of GABAergic and glutamatergic transmission. Eur. J. Neurosci. 18, 3199–3206 (2003).

    PubMed  Google Scholar 

  91. Titz, S. et al. Hyperpolarizing inhibition develops without trophic support by GABA in cultured rat midbrain neurons. J. Physiol. 550, 719–730 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  92. Kanold, P. O. & Shatz, C. J. Subplate neurons regulate maturation of cortical inhibition and outcome of ocular dominance plasticity. Neuron 51, 627–638 (2006).

    CAS  PubMed  Google Scholar 

  93. Liu, Z., Neff, R. A. & Berg, D. K. Sequential interplay of nicotinic and GABAergic signaling guides neuronal development. Science 314, 1610–1613 (2006).

    CAS  PubMed  Google Scholar 

  94. Pfeffer, C. K. et al. NKCC1-dependent GABAergic excitation drives synaptic network maturation during early hippocampal development. J. Neurosci. 29, 3419–3430 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  95. Lacoh, C. M., Bodogan, T., Kaila, K., Fiumelli, H. & Vutskits, L. General anaesthetics do not impair developmental expression of the KCC2 potassium-chloride cotransporter in neonatal rats during the brain growth spurt. Br. J. Anaesth. 110 (Suppl. 1), i10–i18 (2013).

    CAS  PubMed  Google Scholar 

  96. Wojcik, S. M. et al. A shared vesicular carrier allows synaptic corelease of GABA and glycine. Neuron 50, 575–587 (2006).

    CAS  PubMed  Google Scholar 

  97. Nardou, R. et al. Neuronal chloride accumulation and excitatory GABA underlie aggravation of neonatal epileptiform activities by phenobarbital. Brain 134, 987–1002 (2011).

    PubMed  Google Scholar 

  98. Alger, B. E. & Nicoll, R. A. GABA-mediated biphasic inhibitory responses in hippocampus. Nature 281, 315–317 (1979).

    CAS  PubMed  Google Scholar 

  99. Alger, B. E. & Nicoll, R. A. Feed-forward dendritic inhibition in rat hippocampal pyramidal cells studied in vitro. J. Physiol. 328, 105–123 (1982).

    CAS  PubMed  PubMed Central  Google Scholar 

  100. Kaila, K., Lamsa, K., Smirnov, S., Taira, T. & Voipio, J. Long-lasting GABA-mediated depolarization evoked by high- frequency stimulation in pyramidal neurons of rat hippocampal slice is attributable to a network-driven, bicarbonate-dependent K+ transient. J. Neurosci. 17, 7662–7672 (1997).

    CAS  PubMed  PubMed Central  Google Scholar 

  101. Viitanen, T., Ruusuvuori, E., Kaila, K. & Voipio, J. The K+-Cl cotransporter KCC2 promotes GABAergic excitation in the mature rat hippocampus. J. Physiol. 588, 1527–1540 (2010). This study showed that, paradoxically, KCC2 can promote seizures by contributing to pro-ictal extracellular K+ transients.

    CAS  PubMed  PubMed Central  Google Scholar 

  102. Delpire, E., Rauchman, M. I., Beier, D. R., Hebert, S. C. & Gullans, S. R. Molecular cloning and chromosome localization of a putative basolateral Na+-K+-2Cl cotransporter from mouse inner medullary collecting duct (mIMCD-3) cells. J. Biol. Chem. 269, 25677–25683 (1994).

    CAS  PubMed  Google Scholar 

  103. Payne, J. A. et al. Primary structure, functional expression, and chromosomal localization of the bumetanide-sensitive Na-K-Cl cotransporter in human colon. J. Biol. Chem. 270, 17977–17985 (1995).

    CAS  PubMed  Google Scholar 

  104. Randall, J., Thorne, T. & Delpire, E. Partial cloning and characterization of Slc12a2: the gene encoding the secretory Na+-K+-2Cl- cotransporter. Am. J. Physiol. 273, C1267–C1277 (1997).

    CAS  PubMed  Google Scholar 

  105. Hübner, C. A., Lorke, D. E. & Hermans-Borgmeyer, I. Expression of the Na-K-2Cl-cotransporter NKCC1 during mouse development. Mech. Dev. 102, 267–269 (2001).

    PubMed  Google Scholar 

  106. Price, T. J., Hargreaves, K. M. & Cervero, F. Protein expression and mRNA cellular distribution of the NKCC1 cotransporter in the dorsal root and trigeminal ganglia of the rat. Brain Res. 1112, 146–158 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  107. Plotkin, M. D., Snyder, E. Y., Hebert, S. C. & Delpire, E. Expression of the Na-K-2Cl cotransporter is developmentally regulated in postnatal rat brains: a possible mechanism underlying GABA's excitatory role in immature brain. J. Neurobiol. 33, 781–795 (1997).

    CAS  PubMed  Google Scholar 

  108. Aronica, E. et al. Differential expression patterns of chloride transporters, Na+-K+-2Cl—cotransporter and K+-Cl-cotransporter, in epilepsy-associated malformations of cortical development. Neuroscience 145, 185–196 (2007).

    CAS  PubMed  Google Scholar 

  109. Yan, Y., Dempsey, R. J. & Sun, D. Expression of Na+-K+-Cl cotransporter in rat brain during development and its localization in mature astrocytes. Brain Res. 911, 43–55 (2001).

    CAS  PubMed  Google Scholar 

  110. Marty, S., Wehrle, R., Alvarez-Leefmans, F. J., Gasnier, B. & Sotelo, C. Postnatal maturation of Na+, K+, 2Cl- cotransporter expression and inhibitory synaptogenesis in the rat hippocampus: an immunocytochemical analysis. Eur. J. Neurosci. 15, 233–245 (2002).

    PubMed  Google Scholar 

  111. Mikawa, S. et al. Developmental changes in KCC1, KCC2 and NKCC1 mRNAs in the rat cerebellum. Dev. Brain Res. 136, 93–100 (2002).

    CAS  Google Scholar 

  112. Morita, Y. et al. Characteristics of the cation cotransporter NKCC1 in human brain: alternate transcripts, expression in development, and potential relationships to brain function and schizophrenia. J. Neurosci. 34, 4929–4940 (2014).

    PubMed  PubMed Central  Google Scholar 

  113. Vibat, C. R. T., Holland, M. J., Kang, J. J., Putney, L. K. & O'Donnell, M. E. Quantitation of Na+-K+-2Cl cotransport splice variants in human tissues using kinetic polymerase chain reaction. Anal. Biochem. 298, 218–230 (2001).

    CAS  PubMed  Google Scholar 

  114. Pearson, M. M., Lu, J., Mount, D. B. & Delpire, E. Localization of the K-Cl-cotransporter, KCC3, in the central and peripheral nervous systems: expression in the choroid plexus, large neurons and white matter tracts. Neuroscience 103, 481–491 (2001).

    CAS  PubMed  Google Scholar 

  115. Shekarabi, M. et al. Cellular expression of the K+-Cl cotransporter KCC3 in the central nervous system of mouse. Brain Res. 1374, 15–26 (2011).

    CAS  PubMed  Google Scholar 

  116. Boettger, T. et al. Loss of K-Cl co-transporter KCC3 causes deafness, neurodegeneration and reduced seizure threshold. EMBO J. 22, 5422–5434 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  117. Byun, N. & Delpire, E. Axonal and periaxonal swelling precede peripheral neurodegeneration in KCC3 knockout mice. Neurobiol. Dis. 28, 39–51 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  118. Howard, H. C. et al. The K-Cl cotransporter KCC3 is mutant in a severe peripheral neuropathy associated with agenesis of the corpus callosum. Nature Genet. 32, 384–392 (2002).

    CAS  PubMed  Google Scholar 

  119. Shekarabi, M. et al. Loss of neuronal potassium/chloride cotransporter 3 (KCC3) is responsible for the degenerative phenotype in a conditional mouse model of hereditary motor and sensory neuropathy associated with agenesis of the corpus callosum. J. Neurosci. 32, 3865–3876 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  120. Karadsheh, M. F., Byun, N., Mount, D. B. & Delpire, E. Localization of the KCC4 potassium chloride cotransporter in the nervous system. Neuroscience 123, 381–391 (2004).

    CAS  PubMed  Google Scholar 

  121. Rust, M. B. et al. Disruption of erythroid K-Cl cotransporters alters erythrocyte volume and partially rescues erythrocyte dehydration in SAD mice. J. Clin. Invest. 117, 1708–1717 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  122. Boettger, T. et al. Deafness and renal tubular acidosis in mice lacking the K-Cl co-transporter Kcc4. Nature 416, 874–878 (2002).

    CAS  PubMed  Google Scholar 

  123. Zhang, L. L., Fina, M. E. & Vardi, N. Regulation of KCC2 and NKCC during development: membrane insertion and differences between cell types. J. Comp. Neurol. 499, 132–143 (2006).

    CAS  PubMed  Google Scholar 

  124. Lytle, C. & Forbush, B. Regulatory phosphorylation of the secretory Na-K-Cl cotransporter: modulation by cytoplasmic Cl. Am. J. Physiol. 270, C437–C448 (1996).

    CAS  PubMed  Google Scholar 

  125. Haas, M., McBrayer, D. & Lytle, C. Cl-dependent phosphorylation of the Na-K-Cl cotransport protein of dog tracheal epithelial cells. J. Biol. Chem. 270, 28955–28961 (1995).

    CAS  PubMed  Google Scholar 

  126. Williams, J. R. & Payne, J. A. Cation transport by the neuronal K+-Cl cotransporter KCC2: thermodynamics and kinetics of alternate transport modes. Am. J. Physiol. 287, C919–C931 (2004).

    CAS  Google Scholar 

  127. Piala, A. T. et al. Chloride sensing by WNK1 involves inhibition of autophosphorylation. Sci. Signal. 7, ra41 (2014). This work suggests that WNK1 acts as a sensor of the intracellular Cl level through direct binding of a Cl ion to its active site, inhibiting autophosphorylation.

    PubMed  PubMed Central  Google Scholar 

  128. Delpire, E. & Gagnon, K. B. E. SPAK and OSR1: STE20 kinases involved in the regulation of ion homoeostasis and volume control in mammalian cells. Biochem. J. 409, 321–331 (2008).

    CAS  PubMed  Google Scholar 

  129. de los Heros, P. et al. The WNK-regulated SPAK/OSR1 kinases directly phosphorylate and inhibit the K+-Cl co-transporters. Biochem. J. 458, 559–573 (2014).

    CAS  PubMed  Google Scholar 

  130. Alessi, D. R. et al. The WNK-SPAK/OSR1 pathway: master regulator of cation-chloride cotransporters. Sci Signal. 7, re3 (2014).

    PubMed  Google Scholar 

  131. Darman, R. B., Flemmer, A. & Forbush, B. Modulation of ion transport by direct targeting of protein phosphatase type 1 to the Na-K-Cl cotransporter. J. Biol. Chem. 276, 34359–34362 (2001).

    CAS  PubMed  Google Scholar 

  132. Flemmer, A. W., Gimenez, I., Dowd, B. F. X., Darman, R. B. & Forbush, B. Activation of the Na-K-Cl cotransporter NKCC1 detected with a phospho-specific antibody. J. Biol. Chem. 277, 37551–37558 (2002).

    CAS  PubMed  Google Scholar 

  133. Darman, R. B. & Forbush, B. A regulatory locus of phosphorylation in the N terminus of the Na-K-Cl cotransporter, NKCC1. J. Biol. Chem. 277, 37542–37550 (2002).

    CAS  PubMed  Google Scholar 

  134. Piechotta, K., Lu, J. & Delpire, E. Cation chloride cotransporters interact with the stress-related kinases Ste20-related proline-alanine-rich kinase (SPAK) and oxidative stress response 1 (OSR1). J. Biol. Chem. 277, 50812–50819 (2002).

    CAS  PubMed  Google Scholar 

  135. Dowd, B. F. X. & Forbush, B. PASK (proline-alanine-rich STE20-related kinase), a regulatory kinase of the Na-K-Cl cotransporter (NKCC1). J. Biol. Chem. 278, 27347–27353 (2003).

    CAS  PubMed  Google Scholar 

  136. Filippi, B. M. et al. MO25 is a master regulator of SPAK/OSR1 and MST3/MST4/YSK1 protein kinases. EMBO J. 30, 1730–1741 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  137. Gagnon, K. B. & Delpire, E. Multiple pathways for protein phosphatase 1 (PP1) regulation of Na-K-2Cl cotransporter (NKCC1) function: the N-terminal tail of the Na-K-2Cl cotransporter serves as a regulatory scaffold for Ste20-related proline/alanine-rich kinase (SPAK) AND PP1. J. Biol. Chem. 285, 14115–14121 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  138. Markadieu, N. & Delpire, E. Physiology and pathophysiology of SLC12A1/2 transporters. Pflugers Arch. 466, 91–105 (2014).

    CAS  PubMed  Google Scholar 

  139. Rinehart, J. et al. Sites of regulated phosphorylation that control K-Cl cotransporter activity. Cell 138, 525–536 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  140. Inoue, K. et al. Taurine inhibits K+-Cl cotransporter KCC2 to regulate embryonic Cl homeostasis via with-no-lysine (WNK) protein kinase signaling pathway. J. Biol. Chem. 287, 20839–20850 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  141. Kahle, K. T. et al. Modulation of neuronal activity by phosphorylation of the K-Cl cotransporter KCC2. Trends Neurosci. 36, 726–737 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  142. Gulyas, A. I., Sik, A., Payne, J. A., Kaila, K. & Freund, T. F. The KCl cotransporter, KCC2, is highly expressed in the vicinity of excitatory synapses in the rat hippocampus. Eur. J. Neurosci. 13, 2205–2217 (2001). This the first study to report the surprising finding that KCC2 levels are particularly high in and around spines. This boosted subsequent work on a possible structural role for KCC2 in spine formation.

    CAS  PubMed  Google Scholar 

  143. Kovacs, K., Basu, K., Rouiller, I. & Sik, A. Regional differences in the expression of K+–Cl- 2 cotransporter in the developing rat cortex. Brain Struct. Funct. 219, 527–538 (2013).

    PubMed  PubMed Central  Google Scholar 

  144. Weber, M., Hartmann, A. M., Beyer, T., Ripperger, A. & Nothwang, H. G. A novel regulatory locus of phosphorylation in the C terminus of the potassium chloride cotransporter KCC2 that interferes with N-ethylmaleimide or staurosporine-mediated activation. J. Biol. Chem. 289, 18668–18679 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  145. Bos, R. et al. Activation of 5-HT2A receptors upregulates the function of the neuronal K-Cl cotransporter KCC2. Proc. Natl Acad. Sci. USA 110, 348–353 (2013).

    CAS  PubMed  Google Scholar 

  146. Khirug, S. et al. Distinct properties of functional KCC2 expression in immature mouse hippocampal neurons in culture and in acute slices. Eur. J. Neurosci. 21, 899–904 (2005).

    PubMed  Google Scholar 

  147. Lee, H. H. C. et al. Direct protein kinase C-dependent phosphorylation regulates the cell surface stability and activity of the potassium chloride cotransporter KCC2. J. Biol. Chem. 282, 29777–29784 (2007).

    CAS  PubMed  Google Scholar 

  148. Fiumelli, H., Cancedda, L. & Poo, M. M. Modulation of GABAergic transmission by activity via postsynaptic Ca2+-dependent regulation of KCC2 function. Neuron 48, 773–786 (2005).

    CAS  PubMed  Google Scholar 

  149. Lee, H. H., Deeb, T. Z., Walker, J. A., Davies, P. A. & Moss, S. J. NMDA receptor activity downregulates KCC2 resulting in depolarizing GABAA receptor-mediated currents. Nature Neurosci. 14, 736–743 (2011).

    CAS  PubMed  Google Scholar 

  150. Puskarjov, M., Ahmad, F., Kaila, K. & Blaesse, P. Activity-dependent cleavage of the K-Cl cotransporter KCC2 mediated by calcium-activated protease calpain. J. Neurosci. 32, 11356–11364 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  151. Chamma, I. et al. Activity-dependent regulation of the K/Cl transporter KCC2 membrane diffusion, clustering, and function in hippocampal neurons. J. Neurosci. 33, 15488–15503 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  152. Rivera, C. et al. Mechanism of activity-dependent downregulation of the neuron-specific K-Cl cotransporter KCC2. J. Neurosci. 24, 4683–4691 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  153. Laughlin, S. B. & Sejnowski, T. J. Communication in neuronal networks. Science 301, 1870–1874 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  154. Inoue, K., Yamada, J., Ueno, S. & Fukuda, A. Brain-type creatine kinase activates neuron-specific K+-Cl co-transporter KCC2. J. Neurochem. 96, 598–608 (2006).

    CAS  PubMed  Google Scholar 

  155. Salin-Cantegrel, A. et al. HMSN/ACC truncation mutations disrupt brain-type creatine kinase-dependant activation of K+/Cl cotransporter 3. Hum. Mol. Genet. 17, 2703–2711 (2008).

    CAS  PubMed  Google Scholar 

  156. Ikeda, K. et al. Malfunction of respiratory-related neuronal activity in Na+, K+-ATPase α2 subunit-deficient mice is attributable to abnormal Cl homeostasis in brainstem neurons. J. Neurosci. 24, 10693–10701 (2004).

    CAS  PubMed  PubMed Central  Google Scholar 

  157. Klausberger, T. & Somogyi, P. Neuronal diversity and temporal dynamics: the unity of hippocampal circuit operations. Science 321, 53–57 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  158. Sjöström, P. J., Rancz, E. A., Roth, A. & Häusser, M. Dendritic excitability and synaptic plasticity. Physiol. Rev. 88, 769–840 (2008).

    PubMed  Google Scholar 

  159. Gidon, A. & Segev, I. Principles governing the operation of synaptic inhibition in dendrites. Neuron 75, 330–341 (2012).

    CAS  PubMed  Google Scholar 

  160. Jack, J. J. B., Noble, D. & Tsien, R. W. Electric Current Flow in Excitable Cells (Oxford Univ. Press, 1975).

    Google Scholar 

  161. Farrant, M. & Kaila, K. The cellular, molecular and ionic basis of GABAA receptor signalling. Prog. Brain Res. 160, 59–87 (2007).

    CAS  PubMed  Google Scholar 

  162. Fatima-Shad, K. & Barry, P. H. Anion permeation in GABA- and glycine-gated channels of mammalian cultured hippocampal neurons. Proc. R. Soc. Lond. B 253, 69–75 (1993).

    CAS  Google Scholar 

  163. Misgeld, U., Deisz, R. A., Dodt, H. U. & Lux, H. D. The role of chloride transport in postsynaptic inhibition of hippocampal neurons. Science 232, 1413–1415 (1986).

    CAS  PubMed  Google Scholar 

  164. Kaila, K., Voipio, J., Paalasmaa, P., Pasternack, M. & Deisz, R. A. The role of bicarbonate in GABAA receptor-mediated IPSPs of rat neocortical neurones. J. Physiol. 464, 273–289 (1993).

    CAS  PubMed  PubMed Central  Google Scholar 

  165. Chen, G., Trombley, P. Q. & van den Pol, A. N. Excitatory actions of GABA in developing rat hypothalamic neurones. J. Physiol. 494, 451–464 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  166. van den Pol, A. N., Obrietan, K. & Chen, G. Excitatory actions of GABA after neuronal trauma. J. Neurosci. 16, 4283–4292 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  167. Köhling, R. et al. Spontaneous sharp waves in human neocortical slices excised from epileptic patients. Brain 121, 1073–1087 (1998).

    PubMed  Google Scholar 

  168. Kilb, W. et al. Glycine receptors mediate excitation of subplate neurons in neonatal rat cerebral cortex. J. Neurophysiol. 100, 698–707 (2008).

    CAS  PubMed  Google Scholar 

  169. Christie, J. M. & Jahr, C. E. Selective expression of ligand-gated ion channels in L5 pyramidal cell axons. J. Neurosci. 29, 11441–11450 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  170. Farrant, M. & Nusser, Z. Variations on an inhibitory theme: phasic and tonic activation of GABAA receptors. Nature Rev. Neurosci. 6, 215–229 (2005).

    CAS  Google Scholar 

  171. Brickley, S. G. & Mody, I. Extrasynaptic GABAA receptors: their function in the CNS and implications for disease. Neuron 73, 23–34 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  172. Sipilä, S. T., Huttu, K., Soltesz, I., Voipio, J. & Kaila, K. Depolarizing GABA acts on intrinsically bursting pyramidal neurons to drive giant depolarizing potentials in the immature hippocampus. J. Neurosci. 25, 5280–5289 (2005).

    PubMed  PubMed Central  Google Scholar 

  173. Demarque, M. et al. Paracrine intercellular communication by a Ca2+- and SNARE-independent release of GABA and glutamate prior to synapse formation. Neuron 36, 1051–1061 (2002).

    CAS  PubMed  Google Scholar 

  174. Owens, D. F. & Kriegstein, A. R. Is there more to GABA than synaptic inhibition? Nature Rev. Neurosci. 3, 715–727 (2002).

    CAS  Google Scholar 

  175. Luhmann, H. J., Kirischuk, S., Sinning, A. & Kilb, W. Early GABAergic circuitry in the cerebral cortex. Curr. Opin. Neurobiol. 26, 72–78 (2014).

    CAS  PubMed  Google Scholar 

  176. Rivera, C., Voipio, J. & Kaila, K. Two developmental switches in GABAergic signalling: the K+-Cl cotransporter KCC2 and carbonic anhydrase CAVII. J. Physiol. 564, 953 (2005).

    CAS  Google Scholar 

  177. Riekki, R. et al. Altered synaptic dynamics and hippocampal excitability but normal long-term plasticity in mice lacking hyperpolarizing GABAA receptor-mediated inhibition in CA1 pyramidal neurons. J. Neurophysiol. 99, 3075–3089 (2008).

    PubMed  Google Scholar 

  178. Stil, A. et al. Contribution of the potassium-chloride co-transporter KCC2 to the modulation of lumbar spinal networks in mice. Eur. J. Neurosci. 33, 1212–1222 (2011).

    PubMed  Google Scholar 

  179. Zhang, R. W., Zhang, S. Y. & Du, J. L. KCC2-dependent subcellular ECl difference of ON-OFF retinal ganglion cells in larval zebrafish. Front. Neural Circuits 7, 103 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  180. Lee, H., Chen, C. X. Q., Liu, Y. J., Aizenman, E. & Kandler, K. KCC2 expression in immature rat cortical neurons is sufficient to switch the polarity of GABA responses. Eur. J. Neurosci. 21, 2593–2599 (2005).

    PubMed  PubMed Central  Google Scholar 

  181. Cancedda, L., Fiumelli, H., Chen, K. & Poo, M. M. Excitatory GABA action is essential for morphological maturation of cortical neurons in vivo. J. Neurosci. 27, 5224–5235 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  182. Reynolds, A. et al. Neurogenic role of the depolarizing chloride gradient revealed by global overexpression of KCC2 from the onset of development. J. Neurosci. 28, 1588–1597 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  183. Szabadics, J. et al. Excitatory effect of GABAergic axo-axonic cells in cortical microcircuits. Science 311, 233–235 (2006). The authors show that E GABA is spatially non-uniform in cortical pyramidal neurons. Whether the depolarizing GABAergic input at the AIS is functionally excitatory is being debated.

    CAS  PubMed  Google Scholar 

  184. Waseem, T., Mukhtarov, M., Buldakova, S., Medina, I. & Bregestovski, P. Genetically encoded Cl-sensor as a tool for monitoring of Cl-dependent processes in small neuronal compartments. J. Neurosci. Methods 193, 14–23 (2010).

    CAS  PubMed  Google Scholar 

  185. Khirug, S. et al. GABAergic depolarization of the axon initial segment in cortical principal neurons is caused by the Na-K-2Cl cotransporter NKCC1. J. Neurosci. 28, 4635–4639 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  186. Baldi, R., Varga, C. & Tamas, G. Differential distribution of KCC2 along the axo-somato-dendritic axis of hippocampal principal cells. Eur. J. Neurosci. 32, 1319–1325 (2010).

    PubMed  Google Scholar 

  187. Hedstrom, K. L., Ogawa, Y. & Rasband, M. N. AnkyrinG is required for maintenance of the axon initial segment and neuronal polarity. J. Cell Biol. 183, 635–640 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  188. Glickfeld, L. L., Roberts, J. D., Somogyi, P. & Scanziani, M. Interneurons hyperpolarize pyramidal cells along their entire somatodendritic axis. Nature Neurosci. 12, 21–23 (2009).

    CAS  PubMed  Google Scholar 

  189. Viney, T. J. et al. Network state-dependent inhibition of identified hippocampal CA3 axo-axonic cells in vivo. Nature Neurosci. 16, 1802–1811 (2013).

    CAS  PubMed  Google Scholar 

  190. Carmosino, M., Gimenez, I., Caplan, M. & Forbush, B. Exon loss accounts for differential sorting of Na-K-Cl cotransporters in polarized epithelial cells. Mol. Biol. Cell 19, 4341–4351 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  191. Dotti, C. G. & Simons, K. Polarized sorting of viral glycoproteins to the axon and dendrites of hippocampal neurons in culture. Cell 62, 63–72 (1990).

    CAS  PubMed  Google Scholar 

  192. Fatt., P. & Katz, B. The effect of inhibitory nerve impulses on a crustacean muscle fibre. J. Physiol. 121, 374–389 (1953).

    CAS  PubMed  PubMed Central  Google Scholar 

  193. Ruusuvuori, E. & Kaila, K. in Carbonic Anhydrase: Mechanism, Regulation, Links to Disease, and Industrial Applications (eds Frost, S. & McKenna, R.) 271–290 (Springer, 2014).

    Google Scholar 

  194. Chadderton, P., Schaefer, A. T., Williams, S. R. & Margrie, T. W. Sensory-evoked synaptic integration in cerebellar and cerebral cortical neurons. Nature Rev. Neurosci. 15, 71–83 (2014).

    CAS  Google Scholar 

  195. Doyon, N. et al. Efficacy of synaptic inhibition depends on multiple, dynamically interacting mechanisms implicated in chloride homeostasis. PLoS Comput. Biol. 7, e1002149 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  196. Grimley, J. S. et al. Visualization of synaptic inhibition with an optogenetic sensor developed by cell-free protein engineering automation. J. Neurosci. 33, 16297–16309 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  197. Kuner, T. & Augustine, G. J. A genetically encoded ratiometric indicator for chloride: capturing chloride transients in cultured hippocampal neurons. Neuron 27, 447–459 (2000).

    CAS  PubMed  Google Scholar 

  198. Raimondo, J. V. et al. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system. Front. Cell Neurosci. 7, 202 (2013).

    PubMed  PubMed Central  Google Scholar 

  199. Raimondo, J. V., Markram, H. & Akerman, C. J. Short-term ionic plasticity at GABAergic synapses. Front. Synaptic Neurosci. 4, 5 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  200. Wright, R., Raimondo, J. V. & Akerman, C. J. Spatial and temporal dynamics in the ionic driving force for GABAA receptors. Neural Plast. 2011, 728395 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  201. Thompson, S. M. & Gähwiler, B. H. Activity-dependent disinhibition. I. Repetitive stimulation reduces IPSP driving force and conductance in the hippocampus in vitro. J. Neurophysiol. 61, 501–511 (1989).

    CAS  PubMed  Google Scholar 

  202. Staley, K. J., Soldo, B. L. & Proctor, W. R. Ionic mechanisms of neuronal excitation by inhibitory GABAA receptors. Science 269, 977–981 (1995).

    CAS  PubMed  Google Scholar 

  203. Taira, T., Lamsa, K. & Kaila, K. Posttetanic excitation mediated by GABAA receptors in rat CA1 pyramidal neurons. J. Neurophysiol. 77, 2213–2218 (1997).

    CAS  PubMed  Google Scholar 

  204. Ruusuvuori, E. et al. Neuronal carbonic anhydrase VII provides GABAergic excitatory drive to exacerbate febrile seizures. EMBO J. 32, 2275–2286 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  205. Ruscheweyh, R. & Sandkuhler, J. Epileptiform activity in rat spinal dorsal horn in vitro has common features with neuropathic pain. Pain 105, 327–338 (2003). This work demonstrated that the dorsal horn can generate epileptiform activity in a GABA A R-dependent manner.

    PubMed  Google Scholar 

  206. Asiedu, M., Ossipov, M. H., Kaila, K. & Price, T. J. Acetazolamide and midazolam act synergistically to inhibit neuropathic pain. Pain 148, 302–308 (2010).

    CAS  PubMed  Google Scholar 

  207. Asiedu, M. N., Mejia, G. L., Hubner, C. A., Kaila, K. & Price, T. J. Inhibition of carbonic anhydrase augments GABA receptor-mediated analgesia via a spinal mechanism of action. J. Pain 15, 395–406 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  208. Pouille, F. & Scanziani, M. Enforcement of temporal fidelity in pyramidal cells by somatic feed-forward inhibition. Science 293, 1159–1163 (2001).

    CAS  PubMed  Google Scholar 

  209. Hering, H. & Sheng, M. Dendritic spines: structure, dynamics and regulation. Nature Rev. Neurosci. 2, 880–888 (2001).

    CAS  Google Scholar 

  210. Takayama, C. & Inoue, Y. Developmental localization of potassium chloride co-transporter 2 (KCC2), GABA and vesicular GABA transporter (VGAT) in the postnatal mouse somatosensory cortex. Neurosci. Res. 67, 137–148 (2010).

    CAS  PubMed  Google Scholar 

  211. De Felipe, J., Marco, P., Fairen, A. & Jones, E. G. Inhibitory synaptogenesis in mouse somatosensory cortex. Cereb. Cortex 7, 619–634 (1997).

    CAS  PubMed  Google Scholar 

  212. Juraska, J. M. The development of pyramidal neurons after eye opening in the visual cortex of hooded rats: a quantitative study. J. Comp. Neurol. 212, 208–213 (1982).

    CAS  PubMed  Google Scholar 

  213. Huttenlocher, P. R. & Dabholkar, A. S. Regional differences in synaptogenesis in human cerebral cortex. J. Comp. Neurol. 387, 167–178 (1997).

    CAS  PubMed  Google Scholar 

  214. Petanjek, Z. et al. Extraordinary neoteny of synaptic spines in the human prefrontal cortex. Proc. Natl Acad. Sci. USA 108, 13281–13286 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  215. Mercado, A., Broumand, V., Zandi-Nejad, K., Enck, A. H. & Mount, D. B. A C-terminal domain in KCC2 confers constitutive K+-Cl cotransport. J. Biol. Chem. 281, 1016–1026 (2006).

    CAS  PubMed  Google Scholar 

  216. Chamma, I., Chevy, Q., Poncer, J. C. & Levi, S. Role of the neuronal K-Cl co-transporter KCC2 in inhibitory and excitatory neurotransmission. Front. Cell. Neurosci. 6, 5 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  217. Varoqueaux, F., Jamain, S. & Brose, N. Neuroligin 2 is exclusively localized to inhibitory synapses. Eur. J. Cell Biol. 83, 449–456 (2004).

    CAS  PubMed  Google Scholar 

  218. Tyagarajan, S. K. & Fritschy, J. M. Gephyrin: a master regulator of neuronal function? Nature Rev. Neurosci. 15, 141–156 (2014).

    CAS  Google Scholar 

  219. Sun, C. et al. Identification and functional characterization of rare mutations of the neuroligin-2 gene (NLGN2) associated with schizophrenia. Hum. Mol. Genet. 20, 3042–3051 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  220. Ivakine, E. A. et al. Neto2 is a KCC2 interacting protein required for neuronal Cl regulation in hippocampal neurons. Proc. Natl Acad. Sci. USA 110, 3561–3566 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  221. Mahadevan, V. et al. Kainate receptors coexist in a functional complex with KCC2 and regulate chloride homeostasis in hippocampal neurons. Cell Rep. 7, 1762–1770 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  222. Kubota, Y., Hatada, S., Kondo, S., Karube, F. & Kawaguchi, Y. Neocortical inhibitory terminals innervate dendritic spines targeted by thalamocortical afferents. J. Neurosci. 27, 1139–1150 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  223. Chiu, C. Q. et al. Compartmentalization of GABAergic inhibition by dendritic spines. Science 340, 759–762 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  224. Rose, C. R. & Konnerth, A. NMDA receptor-mediated Na+ signals in spines and dendrites. J. Neurosci. 21, 4207–4214 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  225. Jensen, F. E. Epilepsy as a spectrum disorder: implications from novel clinical and basic neuroscience. Epilepsia 52 (Suppl. 1), 1–6 (2011).

    PubMed  PubMed Central  Google Scholar 

  226. Haider, B. & McCormick, D. A. Rapid neocortical dynamics: cellular and network mechanisms. Neuron 62, 171–189 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  227. Uusisaari, M., Smirnov, S., Voipio, J. & Kaila, K. Spontaneous epileptiform activity mediated by GABAA receptors and gap junctions in the rat hippocampal slice following long-term exposure to GABAB antagonists. Neuropharmacology 43, 563–572 (2002).

    CAS  PubMed  Google Scholar 

  228. Pavlov, I., Kaila, K., Kullmann, D. M. & Miles, R. Cortical inhibition, pH and cell excitability in epilepsy: what are optimal targets for antiepileptic interventions? J. Physiol. 591, 765–774 (2013).

    CAS  PubMed  Google Scholar 

  229. Woo, N. S. et al. Hyperexcitability and epilepsy associated with disruption of the mouse neuronal-specific K-Cl cotransporter gene. Hippocampus 12, 258–268 (2002).

    CAS  PubMed  Google Scholar 

  230. Tornberg, J., Voikar, V., Savilahti, H., Rauvala, H. & Airaksinen, M. S. Behavioural phenotypes of hypomorphic KCC2-deficient mice. Eur. J. Neurosci. 21, 1327–1337 (2005).

    PubMed  Google Scholar 

  231. Kahle, K. T. et al. Genetically encoded impairment of neuronal KCC2 cotransporter function in human idiopathic generalized epilepsy. EMBO Rep. 15, 766–774 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  232. Marchionni, I. & Maccaferri, G. Quantitative dynamics and spatial profile of perisomatic GABAergic input during epileptiform synchronization in the CA1 hippocampus. J. Physiol. 587, 5691–5708 (2009).

    CAS  PubMed  PubMed Central  Google Scholar 

  233. Cohen, I., Navarro, V., Clemenceau, S., Baulac, M. & Miles, R. On the origin of interictal activity in human temporal lobe epilepsy in vitro. Science 298, 1418–1421 (2002).

    CAS  PubMed  Google Scholar 

  234. Huberfeld, G. et al. Perturbed chloride homeostasis and GABAergic signaling in human temporal lobe epilepsy. J. Neurosci. 27, 9866–9873 (2007). This work showed that a depolarized E GABA and consequent interictal activity in subicular tissue from patients with temporal lobe epilepsy are based on a loss of KCC2 in a subpopulation of principal neurons.

    CAS  PubMed  PubMed Central  Google Scholar 

  235. Miles, R., Blaesse, P., Huberfeld, G., Wittner, L. & Kaila, K. in Jasper's Basic Mechanisms of the Epilepsies 4th edn (eds Noebels, J. L., Avoli, M., Rogawski, M. A., Olsen, R. W. & Delgado-Escueta, A. V.) 581–590 (Oxford Univ. Press, 2012).

    Google Scholar 

  236. Töllner, K. et al. A novel prodrug-based strategy to increase effects of bumetanide in epilepsy. Ann. Neurol. 75, 550–562 (2014).

    PubMed  Google Scholar 

  237. Gagnon, M. et al. Chloride extrusion enhancers as novel therapeutics for neurological diseases. Nature Med. 19, 1524–1528 (2013).

    CAS  PubMed  Google Scholar 

  238. Jiruska, P. et al. Synchronization and desynchronization in epilepsy: controversies and hypotheses. J. Physiol. 591, 787–797 (2013).

    CAS  PubMed  Google Scholar 

  239. Bialer, M. Why are antiepileptic drugs used for nonepileptic conditions? Epilepsia 53 (Suppl. 7), 26–33 (2012).

    CAS  PubMed  Google Scholar 

  240. Ferrini, F. & De Koninck, Y. Microglia control neuronal network excitability via BDNF signalling. Neural Plast. 2013, 429815 (2013).

    PubMed  PubMed Central  Google Scholar 

  241. Doyon, N., Ferrini, F., Gagnon, M. & De, K. Y. Treating pathological pain: is KCC2 the key to the gate? Expert. Rev. Neurother. 13, 469–471 (2013).

    CAS  PubMed  Google Scholar 

  242. Lorenzo, L. E. et al. Gephyrin clusters are absent from small diameter primary afferent terminals despite the presence of GABAA receptors. J. Neurosci. 34, 8300–8317 (2014).

    PubMed  PubMed Central  Google Scholar 

  243. Melzack, R. & Wall, P. D. Pain mechanisms: a new theory. Science 150, 971–979 (1965). This pioneering theoretical paper set the stage for much of the current work done on the role of CCCs in pain.

    CAS  PubMed  Google Scholar 

  244. Willis, W. D. Jr Dorsal root potentials and dorsal root reflexes: a double-edged sword. Exp. Brain Res. 124, 395–421 (1999).

    CAS  PubMed  Google Scholar 

  245. Price, T. J., Cervero, F., Gold, M. S., Hammond, D. L. & Prescott, S. A. Chloride regulation in the pain pathway. Brain Res. Rev. 60, 149–170 (2009).

    CAS  PubMed  Google Scholar 

  246. Cho, H. et al. The calcium-activated chloride channel anoctamin 1 acts as a heat sensor in nociceptive neurons. Nature Neurosci. 15, 1015–1021 (2012).

    CAS  PubMed  Google Scholar 

  247. Kingery, W. S., Fields, R. D. & Kocsis, J. D. Diminished dorsal root GABA sensitivity following chronic peripheral nerve injury. Exp. Neurol. 100, 478–490 (1988).

    CAS  PubMed  Google Scholar 

  248. Granados-Soto, V., Arguelles, C. F. & Alvarez-Leefmans, F. J. Peripheral and central antinociceptive action of Na+-K+-2Cl- cotransporter blockers on formalin-induced nociception in rats. Pain 114, 231–238 (2005).

    CAS  PubMed  Google Scholar 

  249. Pitcher, M. H., Price, T. J., Entrena, J. M. & Cervero, F. Spinal NKCC1 blockade inhibits TRPV1-dependent referred allodynia. Mol. Pain 3, 17 (2007).

    PubMed  PubMed Central  Google Scholar 

  250. Pitcher, M. H. & Cervero, F. Role of the NKCC1 co-transporter in sensitization of spinal nociceptive neurons. Pain 151, 756–762 (2010).

    CAS  PubMed  Google Scholar 

  251. Lavertu, G., Cote, S. L. & De, K. Y. Enhancing K-Cl co-transport restores normal spinothalamic sensory coding in a neuropathic pain model. Brain 137, 724–738 (2014).

    PubMed  Google Scholar 

  252. Jolivalt, C. G., Lee, C. A., Ramos, K. M. & Calcutt, N. A. Allodynia and hyperalgesia in diabetic rats are mediated by GABA and depletion of spinal potassium-chloride co-transporters. Pain 140, 48–57 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  253. Ferrini, F. et al. Morphine hyperalgesia gated through microglia-mediated disruption of neuronal Cl homeostasis. Nature Neurosci. 16, 183–192 (2013).

    CAS  PubMed  Google Scholar 

  254. Jean-Xavier, C., Pflieger, J. F., Liabeuf, S. & Vinay, L. Inhibitory postsynaptic potentials in lumbar motoneurons remain depolarizing after neonatal spinal cord transection in the rat. J. Neurophysiol. 96, 2274–2281 (2006).

    PubMed  Google Scholar 

  255. Keller, A. F., Beggs, S., Salter, M. W. & De Koninck, Y. Transformation of the output of spinal lamina I neurons after nerve injury and microglia stimulation underlying neuropathic pain. Mol. Pain 3, 27 (2007).

    PubMed  PubMed Central  Google Scholar 

  256. Coull, J. A. M. et al. BDNF from microglia causes the shift in neuronal anion gradient underlying neuropathic pain. Nature 438, 1017–1021 (2005).

    CAS  PubMed  Google Scholar 

  257. Lee-Kubli, C. A. & Calcutt, N. A. Altered rate-dependent depression of the spinal H-reflex as an indicator of spinal disinhibition in models of neuropathic pain. Pain 155, 250–260 (2014).

    PubMed  Google Scholar 

  258. Zhang, Z., Wang, X., Wang, W., Lu, Y. G. & Pan, Z. Z. Brain-derived neurotrophic factor-mediated downregulation of brainstem K+-Cl cotransporter and cell-type-specific GABA impairment for activation of descending pain facilitation. Mol. Pharmacol. 84, 511–520 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  259. Maguire, J. & Salpekar, J. A. Stress, seizures, and hypothalamic–pituitary–adrenal axis targets for the treatment of epilepsy. Epilepsy Behav. 26, 352–362 (2013).

    PubMed  Google Scholar 

  260. Nichol, J. A. & Hutter, O. F. Tensile strength and dilatational elasticity of giant sarcolemmal vesicles shed from rabbit muscle. J. Physiol. 493, 187–198 (1996).

    CAS  PubMed  PubMed Central  Google Scholar 

  261. Gauthier, N. C., Masters, T. A. & Sheetz, M. P. Mechanical feedback between membrane tension and dynamics. Trends Cell Biol. 22, 527–535 (2012).

    CAS  PubMed  Google Scholar 

  262. de los Heros, P. et al. WNK3 bypasses the tonicity requirement for K-Cl cotransporter activation via a phosphatase-dependent pathway. Proc. Natl Acad. Sci. USA 103, 1976–1981 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  263. Payne, J. A. Functional characterization of the neuronal-specific K-Cl cotransporter: implications for [K+]o regulation. Am. J. Physiol. 42, C1516–C1525 (1997).

    Google Scholar 

  264. Strange, K., Singer, T. D., Morrison, R. & Delpire, E. Dependence of KCC2 K-Cl cotransporter activity on a conserved carboxy terminus tyrosine residue. Am. J. Physiol. 279, C860–C867 (2000).

    CAS  Google Scholar 

  265. Cala, P. M. in Chloride Channels and Carriers in Nerve, Muscle, and Glial Cells (eds Alvarez-Leefmans, F. J. & Russell, J. M.) 67–83 (Plenum, 1990).

    Google Scholar 

  266. Amiry-Moghaddam, M. & Ottersen, O. P. The molecular basis of water transport in the brain. Nature Rev. Neurosci. 4, 991–1001 (2003).

    CAS  Google Scholar 

  267. Jefferys, J. G. Nonsynaptic modulation of neuronal activity in the brain: electric currents and extracellular ions. Physiol. Rev. 75, 689–723 (1995).

    CAS  PubMed  Google Scholar 

  268. Larsen, B. R. et al. Contributions of the Na+/K+-ATPase, NKCC1, and Kir4.1 to hippocampal K+ clearance and volume responses. Glia 62, 608–622 (2014).

    PubMed  PubMed Central  Google Scholar 

  269. Andrew, R. D., Labron, M. W., Boehnke, S. E., Carnduff, L. & Kirov, S. A. Physiological evidence that pyramidal neurons lack functional water channels. Cereb. Cortex 17, 787–802 (2007).

    PubMed  Google Scholar 

  270. Alvarez-Leefmans, F. J., Gamino, S. M., Giraldez, F. & Nogueron, I. Intracellular chloride regulation in amphibian dorsal root ganglion neurones studied with ion-selective microelectrodes. J. Physiol. 406, 225–246 (1988).

    CAS  PubMed  PubMed Central  Google Scholar 

  271. Shields, S. D., Mazario, J., Skinner, K. & Basbaum, A. I. Anatomical and functional analysis of aquaporin 1, a water channel in primary afferent neurons. Pain 131, 8–20 (2007).

    CAS  PubMed  Google Scholar 

  272. Hille, B. Ionic Channels of Excitable Membranes 3rd edn (Sinauer Associates, 2001).

    Google Scholar 

  273. Tosteson, D. C. & Hoffman, J. F. Regulation of cell volume by active cation transport in high and low potassium sheep red cells. J. Gen. Physiol. 44, 169–194 (1960).

    CAS  PubMed  PubMed Central  Google Scholar 

  274. Jarolimek, W., Lewen, A. & Misgeld, U. A furosemide-sensitive K+-Cl cotransporter counteracts intracellular Cl accumulation and depletion in cultured rat midbrain neurons. J. Neurosci. 19, 4695–4704 (1999).

    CAS  PubMed  PubMed Central  Google Scholar 

  275. Cordero-Erausquin, M., Coull, J. A., Boudreau, D., Rolland, M. & De Koninck, Y. Differential maturation of GABA action and anion reversal potential in spinal lamina I neurons: impact of chloride extrusion capacity. J. Neurosci. 25, 9613–9623 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  276. McLaughlin, S. G., Szabo, G. & Eisenman, G. Divalent ions and the surface potential of charged phospholipid membranes. J. Gen. Physiol. 58, 667–687 (1971).

    CAS  PubMed  PubMed Central  Google Scholar 

  277. Honig, B. & Nicholls, A. Classical electrostatics in biology and chemistry. Science 268, 1144–1149 (1995).

    CAS  PubMed  Google Scholar 

  278. Kaila, K., Pasternack, M., Saarikoski, J. & Voipio, J. Influence of GABA-gated bicarbonate conductance on potential, current and intracellular chloride in crayfish muscle fibres. J. Physiol. 416, 161–181 (1989).

    CAS  PubMed  PubMed Central  Google Scholar 

  279. Armstrong, C. M. The Na/K pump, Cl ion, and osmotic stabilization of cells. Proc. Natl Acad. Sci. USA 100, 6257–6262 (2003).

    CAS  PubMed  PubMed Central  Google Scholar 

  280. Glykys, J. et al. Local impermeant anions establish the neuronal chloride concentration. Science 343, 670–675 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  281. Voipio, J. et al. Comment on “Local impermeant anions establish the neuronal chloride concentration”. Science 345, 1130 (2014).

    CAS  PubMed  Google Scholar 

  282. Lee, H. H., Jurd, R. & Moss, S. J. Tyrosine phosphorylation regulates the membrane trafficking of the potassium chloride co-transporter KCC2. Mol. Cell Neurosci. 45, 173–179 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  283. Barmashenko, G., Hefft, S., Aertsen, A., Kirschstein, T. & Kohling, R. Positive shifts of the GABAA receptor reversal potential due to altered chloride homeostasis is widespread after status epilepticus. Epilepsia 52, 1570–1578 (2011).

    CAS  PubMed  Google Scholar 

  284. Papp, E., Rivera, C., Kaila, K. & Freund, T. F. Relationship between neuronal vulnerability and potassium-chloride cotransporter 2 immunoreactivity in hippocampus following transient forebrain ischemia. Neuroscience 154, 677–689 (2008).

    CAS  PubMed  Google Scholar 

  285. Bonislawski, D. P., Schwarzbach, E. P. & Cohen, A. S. Brain injury impairs dentate gyrus inhibitory efficacy. Neurobiol. Dis. 25, 163–169 (2007).

    CAS  PubMed  Google Scholar 

  286. Jantzie, L. L. et al. Erythropoietin attenuates loss of potassium chloride co-transporters following prenatal brain injury. Mol. Cell. Neurosci. 61, 152–162 (2014).

    CAS  PubMed  Google Scholar 

  287. Amini, M. et al. Conditional disruption of calpain in the CNS alters dendrite morphology, impairs LTP, and promotes neuronal survival following injury. J. Neurosci. 33, 5773–5784 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  288. Andres, A. L. et al. NMDA receptor activation and calpain contribute to disruption of dendritic spines by the stress neuropeptide CRH. J. Neurosci. 33, 16945–16960 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  289. He, X. P., Pan, E., Sciarretta, C., Minichiello, L. & McNamara, J. O. Disruption of TrkB-mediated phospholipase Cγ signaling inhibits limbic epileptogenesis. J. Neurosci. 30, 6188–6196 (2010).

    CAS  PubMed  PubMed Central  Google Scholar 

  290. He, X. P., Wen, R. & McNamara, J. O. Impairment of kindling development in phospholipase Cγ1 heterozygous mice. Epilepsia 55, 456–463 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

  291. Carmona, M. A. et al. Age-dependent spontaneous hyperexcitability and impairment of GABAergic function in the hippocampus of mice lacking trkB. Cereb. Cortex 16, 47–63 (2006).

    PubMed  Google Scholar 

  292. Knusel, B., Rabin, S. J., Hefti, F. & Kaplan, D. R. Regulated neurotrophin receptor responsiveness during neuronal migration and early differentiation. J. Neurosci. 14, 1542–1554 (1994).

    CAS  PubMed  PubMed Central  Google Scholar 

  293. Di Lieto, A. et al. The responsiveness of TrkB to BDNF and antidepressant drugs is differentially regulated during mouse development. PLoS ONE 7, e32869 (2012).

    CAS  PubMed  PubMed Central  Google Scholar 

  294. Shulga, A. et al. Posttraumatic GABAA-mediated [Ca2+]i increase is essential for the induction of brain-derived neurotrophic factor-dependent survival of mature central neurons. J. Neurosci. 28, 6996–7005 (2008).

    CAS  PubMed  PubMed Central  Google Scholar 

  295. Kang, H. J. et al. Spatio-temporal transcriptome of the human brain. Nature 478, 483–489 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  296. Ge, S. et al. GABA regulates synaptic integration of newly generated neurons in the adult brain. Nature 439, 589–593 (2006).

    CAS  PubMed  Google Scholar 

  297. Glykys, J. et al. Response to Comments on “Local impermeant anions establish the neuronal chloride concentration”. Science 345, 1130 (2014).

    CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

The authors thank B. Forbush for kindly providing the KCC2 and NKCC1 two-dimensional models that were adapted for figure 1d, and P. Blaesse, T. Z. Deeb, M. S. Gold, E. Ruusuvuori, P. Seja, R.-L. Uronen and L. Vutskits for comments and suggestions on an early version of this manuscript. The authors original research work is funded by the European Research Council Advanced Grant, Academy of Finland (AoF), AoF (ERA-Net NEURON II CIPRESS), the Sigrid Jusélius Foundation, the Jane and Aatos Erkko Foundation (K.K., M.P. and J.V.), US National Institutes of Health grants NS065926, GM102575 (T.J.P.) and NS36296 (J.A.P.).

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Supplementary information S1 (figure)

Neuronal chloride and bicarbonate regulation sets the reversal potential of GABAAR and GlyR mediated currents. (PDF 262 kb)

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Energetics of anion regulation (PDF 263 kb)

Glossary

Inhibitory postsynaptic potentials

(IPSPs). Synaptic potentials elicited by GABA or glycine that inhibit postsynaptic excitation and the generation of action potentials.

Reversal potential

The membrane potential at which a channel-mediated current reverses its polarity.

Driving force

The electrical potential difference that drives a conductive current. The driving force is calculated as the difference between the membrane potential and either the equilibrium (Nernst) potential of a single ion species or the reversal potential of a channel-mediated current.

Bulk ion concentrations

Ion concentrations in intracellular and extracellular compartments in which the vicinity of the membrane surface has no effect. All intracellular microelectrode measurements of membrane potentials yield data on the voltage between these bulk phases.

Shunting inhibition

Suppression of postsynaptic excitation that results from an increase in neuronal membrane conductance that is caused by activation of GABAA receptors or glycine receptors.

Excitatory postsynaptic currents

(EPSCs). Inward currents elicited by excitatory neurotransmitters (typically glutamate) that depolarize the neuron to enhance spiking probability.

Space and time constants

Reflect the passive electrical properties of neurons. The time constant (τm) is the product of membrane resistance and capacitance (τm = Rm·Cm) and defines the rate of change of a passive membrane potential (Vm) response evoked by a current pulse. The space constant (λ) quantifies the spatial extent of passively spreading signals in an elongated structure, such as a dendrite. Note that inducing an inhibitory conductance produces a decrease in both τm and λ.

Equilibrium potential

The membrane potential at which a single ion species is at equilibrium across the membrane; given by the Nernst equation.

Axon initial segment

(AIS). A structurally and functionally specialized region between the neuronal soma and axon proper that has a low voltage threshold for action potential generation and therefore often acts as the main site of spike initiation.

Tonic inhibition

Inhibition resulting from activation of extrasynaptic high-affinity GABAA receptors.

Integrate-and-fire

A situation in which excitatory inputs impinging on a neuron's dendritic tree are summed up both spatially (from different locations) and temporally (during a high-frequency sequence of excitatory signals) to trigger spiking.

Coincidence detection

A situation in which spiking occurs in response to near-simultaneous, spatially distinct excitatory signals. If a large increase in the neuron's conductance (a fall in time and space constants) takes place (for example, because of GABAergic inhibition), an integrate-and-fire mode of operation will change into coincidence detection.

Excitation/inhibition balance

(E/I balance). The relative quantitative contributions of excitatory and inhibitory synaptic signals at the level of a single neuron or a neuronal network.

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Kaila, K., Price, T., Payne, J. et al. Cation-chloride cotransporters in neuronal development, plasticity and disease. Nat Rev Neurosci 15, 637–654 (2014). https://doi.org/10.1038/nrn3819

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