Activity dependent localization of synaptic NMDA receptors in spinal neurons.
In cultured spinal neurons, NMDA receptors are absent from excitatory synapses under basal conditions, but can be made to appear at excitatory synapses following blockade of excitatory synaptic activity. The activity dependent synaptic localization of NMDA receptors is critically dependent on both the gradual, global accumulation of the NR2A and NR2B subunits and on a rapid, surface redistribution phase that is primed by the accumulation of NR2A and NR2B and inhibited by synaptic activity. Global changes in NR2A and NR2B accumulation and heterogeneous increases in synaptic NMDA receptor localization can also result from inhibitors of proteasomal processing, from manipulations of proteasomal subunit composition and from media conditioned by neurons undergoing synaptic scaling. While proteasomal processing is a mechanism shared with AMPA receptor scaling in cultured spinal neurons, diffusible factors, heterogeneity, and a rapid surface redistribution phase appear to be unique to activity dependent synaptic NMDA receptor localization.
Rosen
Kenneth M
KM
Department of Neurology, Caritas St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, MA 02135, USA.
Moghekar
Abhay
A
O'Brien
Richard J
RJ
D000818:Animals; D015152:Blotting, Northern; D002478:Cells, Cultured; D015870:Gene Expression; D020869:Gene Expression Profiling; D007150:Immunohistochemistry; D009474:Neurons / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D051381:Rats; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000166:cytology* / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D014162:Transfection
D016194:Receptors, N-Methyl-D-Aspartate; D046988:Proteasome Endopeptidase Complex