Neuron
Volume 59, Issue 2, 31 July 2008, Pages 261-273
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Article
Homeostatic Regulation of Synaptic GlyR Numbers Driven by Lateral Diffusion

https://doi.org/10.1016/j.neuron.2008.05.030Get rights and content
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Summary

In the spinal cord, most inhibitory synapses have a mixed glycine-GABA phenotype. Using a pharmacological approach, we report an NMDAR activity-dependent regulation of the mobility of GlyRs but not GABAARs at inhibitory synapses in cultured rat spinal cord neurons. The NMDAR-induced decrease in GlyR lateral diffusion was correlated with an increase in receptor cluster number and glycinergic mIPSC amplitude. Changes in GlyR diffusion properties occurred rapidly and before the changes in the number of synaptic receptors. Regulation of synaptic GlyR content occurred without change in the amount of gephyrin. Moreover, NMDAR-dependent regulation of GlyR lateral diffusion required calcium influx and calcium release from stores. Therefore, excitation may increase GlyR levels at synapses by a calcium-mediated increase in postsynaptic GlyR trapping involving regulation of receptor-scaffold interactions. This provides a mechanism for a rapid homeostatic regulation of the inhibitory glycinergic component at mixed glycine-GABA synapses in response to increased NMDA excitatory transmission.

CELLBIO
MOLIMMUNO
SIGNALING

Cited by (0)

2

Present address: Plasticity in Cortical Networks & Epilepsy, INSERM UMR-839, Institut du Fer à Moulin, 17 rue du Fer à Moulin, 75005 Paris, France

3

Present address: Laboratory for Developmental Neurobiology, Brain Science Institute, RIKEN, Saitama 351-0198, Japan