QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

HOME  |   SEARCH  |   ARCHIVE  |   SUBSCRIBE  |   CONTACT  |   HELP

The Journal of Neuroscience, March 9, 2005, 25(10):2576-2585; doi:10.1523/JNEUROSCI.4118-04.2005

This Article Full Text Full Text (PDF) Submit an eLetter Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (21) Citing Articles via Google Scholar Google Scholar Articles by Amir, R. Articles by Devor, M. Search for Related Content PubMed PubMed Citation Articles by Amir, R. Articles by Devor, M.

 Previous Article  |  Next Article 

Behavioral/Systems/Cognitive
Multiple Interacting Sites of Ectopic Spike Electrogenesis in Primary Sensory Neurons

Ron Amir,¹ Jeffery D. Kocsis,² and Marshall Devor¹

¹Department of Cell and Animal Biology and the Center for Research on Pain, Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel, and ²Department of Neurology, Paralyzed Veterans of America/Eastern Paralyzed Veterans of America Neuroscience and Regeneration Research Center, Yale University School of Medicine, New Haven, Connecticut 06516

Ectopic discharge generated in injured afferent axons and cell somata in vivo contributes significantly to chronic neuropathic dysesthesia and pain after nerve trauma. Progress has been made toward understanding the processes responsible for this discharge using a preparation consisting of whole excised dorsal root ganglia (DRGs) with the cut nerve attached. In the in vitro preparation, however, spike activity originates in the DRG cell soma but rarely in the axon. We have now overcome this impediment to understanding the overall electrogenic processes in soma and axon, including the resulting discharge patterns, by modifying the bath medium in which recordings are made. At both sites, bursts can be triggered by subthreshold oscillations, a phasic stimulus, or spikes arising elsewhere in the neuron. In the soma, once triggered, bursts are maintained by depolarizing afterpotentials, whereas in the axon, an additional process also plays a role, delayed depolarizing potentials. This alternative process appears to be involved in "clock-like" bursting, a discharge pattern much more common in axons than somata. Ectopic spikes arise alternatively in the soma, the injured axon end (neuroma), and the region of the axonal T-junction. Discharge sequences, and even individual multiplet bursts, may be a mosaic of action potentials that originate at these alternative electrogenic sites within the neuron. Correspondingly, discharge generated at these alternative sites may interact, explaining the sometimes-complex firing patterns observed in vivo.

Key words: 4-AP; afterdischarge; ectopic firing; pain; repetitive firing; subthreshold oscillations

---

Received Oct 5, 2004; revised December 19, 2004; accepted January 11, 2005.

This article has been cited by other articles:

				C. Ma and R. H. LaMotte Multiple Sites for Generation of Ectopic Spontaneous Activity in Neurons of the Chronically Compressed Dorsal Root Ganglion J. Neurosci., December 19, 2007; 27(51): 14059 - 14068. [Abstract] [Full Text] [PDF]

				W. Xie, J. A. Strong, H. Li, and J.-M. Zhang Sympathetic Sprouting Near Sensory Neurons After Nerve Injury Occurs Preferentially on Spontaneously Active Cells and Is Reduced by Early Nerve Block J Neurophysiol, January 1, 2007; 97(1): 492 - 502. [Abstract] [Full Text] [PDF]

				O. Poirot, T. Berta, I. Decosterd, and S. Kellenberger Distinct ASIC currents are expressed in rat putative nociceptors and are modulated by nerve injury J. Physiol., October 1, 2006; 576(1): 215 - 234. [Abstract] [Full Text] [PDF]

				S. Balasubramanyan, P. L. Stemkowski, M. J. Stebbing, and P. A. Smith Sciatic Chronic Constriction Injury Produces Cell-Type-Specific Changes in the Electrophysiological Properties of Rat Substantia Gelatinosa Neurons J Neurophysiol, August 1, 2006; 96(2): 579 - 590. [Abstract] [Full Text] [PDF]

				X.-J. Song, Z.-B. Wang, Q. Gan, and E. T. Walters cAMP and cGMP Contribute to Sensory Neuron Hyperexcitability and Hyperalgesia in Rats With Dorsal Root Ganglia Compression J Neurophysiol, January 1, 2006; 95(1): 479 - 492. [Abstract] [Full Text] [PDF]

				S. Andjelic and V. Torre Calcium Dynamics and Compartmentalization in Leech Neurons J Neurophysiol, December 1, 2005; 94(6): 4430 - 4440. [Abstract] [Full Text] [PDF]

				M. Pertin, R.-R. Ji, T. Berta, A. J. Powell, L. Karchewski, S. N. Tate, L. L. Isom, C. J. Woolf, N. Gilliard, D. R. Spahn, et al. Upregulation of the Voltage-Gated Sodium Channel {beta}2 Subunit in Neuropathic Pain Models: Characterization of Expression in Injured and Non-Injured Primary Sensory Neurons J. Neurosci., November 23, 2005; 25(47): 10970 - 10980. [Abstract] [Full Text] [PDF]

Home  |   Search  |   Archive  |   Subscribe  |   Contact  |   Help