Cytoskeletal organization at the postsynaptic complex.
Postsynaptic densities and the adjacent cytoskeleton were examined in deep-etched, unfixed slices of guinea pig anteroventral cochlear nucleus. The postsynaptic density seen in conventional thin sections corresponds to a meshwork of 4-nm filaments associated with intramembrane particles at the postsynaptic active zone of inhibitory as well as excitatory synapses. These filaments intermesh with a lattice of 8- to 9-nm microfilaments, tentatively identified as F-actin, that is concentrated under the postsynaptic density. We postulate that the meshwork of 4-nm filaments anchors receptors to the adjacent microfilament lattice; this extended postsynaptic complex may limit the mobility of receptors and help maintain the curvature of the postsynaptic membrane.
D000818:Animals; D001921:Brain / Q000648:ultrastructure*; D003599:Cytoskeleton / Q000648:ultrastructure*; D005613:Freeze Etching / Q000379:methods; D006168:Guinea Pigs; D013569:Synapses / Q000648:ultrastructure*; D013570:Synaptic Membranes / Q000648:ultrastructure*