Fig. 7.1.13. Free postsynaptic density in the dendritic spine (S) apposed to the pyramidal cell (P) plasma membrane. Neuronal subplasmalemmal cistern is accompanying the naked postsynaptic density (arrow). Scale = 200 nm. (Mouse, neocortex.) (Adapted from Spacek 1982, with kind permission of Kluwer Academic Publishers.) Download the  high resolution image.