[Free postsynaptic-like compactions in the inferior olivary complex of the suslik (Citellus citellus L.)]

The morphological peculiarities of the neuropil [correction of neuropapilea] in the inferior olivary complex of young and elderly ground squirrels were studied by and electron microscope during periods of hibernation and waking. In some of the distal and middle dendrites and dendritic spines [correction of prickles] in elderly ground squirrels there were plaques, composed of electron-dense material with structure similar to postsynaptic condensations, but without presynaptic specializations of chemical synapses. The free postsynaptic-like condensations are located usually in dendrites, which fit to the cellular bodies and sprouts of oligodendrocytes, myelin sheath of nerve fibers and more rarely to astrocytes or lamellae and in single cases to neuronal perikaryon. The significance of the free postsynaptic-like condensations and their connection with age changes in the central nervous system is discussed on the basis of the comparative analysis of the morphological characteristics of the neuropil [correction of neuropapilea] in young and elderly ground squirrels during various seasons.