[Ultrastructural changes in the septum pellucidum of the cat brain after its long-term self-stimulation].

During prolonged electrical stimulation of the septum (self-stimulation 2-3 h daily for 2.5 months) perikarion of most neurons, situated around the tip of the stimulating electrode undergoes peripheral chromatolysis, less part of the neurons is shrunk, mitochondria are desorganized, invaginations of the nuclear membrane occur more often and deeper. Intercellular clefts are sharply dilated, profiles of altered myelin fibers are observed, presynaptic terminals decrease in their number. Axonal terminals with agglutinated vesicles become more numerous. In other terminals osmiophilic bodies and membranous inclusions are revealed. Under electric stimulation a sharp reaction of glial cells, especially astrocytes is observed. One group of astrocytes participate in phagocytosis of the degenerating structures, while the other--in formation of the glial scar.