Role of Actin in Anchoring Postsynaptic Receptors in Cultured Hippocampal Neurons: Differential Attachment of NMDA versus AMPA Receptors

摘要: We used actin-perturbing agents and detergent extraction of primary hippocampal cultures to test directly the role actin cytoskeleton in localizing GABAA receptors, AMPA- NMDA-type glutamate potential anchoring proteins at postsynaptic sites. Excitatory sites on dendritic spines contained a high concentration F-actin that was resistant cytochalasin D but could be depolymerized using novel compound latrunculin A. Depolymerization led 40% decrease both number synaptic NMDA receptor (NMDAR1) clusters AMPA (GluR1)-labeled spines. The nonsynaptic receptors appeared remain clustered coalesce cell bodies. α-Actinin-2, which binds dissociated from clusters, PSD-95 remained associated with consistent proposed cross-linking function. behaved differently; GABAergic neurons, redistributed sites, whereas pyramidal many disperse. Furthermore, control were extractable spines, neurons unextractable. not dependent for maintenance or localization clusters. These results indicate fundamental differences mechanisms regarding single (the receptor) cells versus interneurons different (AMPA vs receptors) class