Submicroscopic changes of cortex nerve cells in chronic mirror epileptic focus in rats.

Submicroscopic changes of neurons, synapses, glial cells and some elements of capillaries were established by studying chronic mirror foci which appeared in the rat cerebral cortex after implantation of cobalt-gelatinous rods into the contralateral hemisphere. The results were compared with normal control cortex and with changes after thermocoagulation of the symmetrical contralateral cortex. It is shown that epileptogenic lesions produce a significant reduction of RNA-components, edema and vacuolization of neuronal cytoplasm, hypertrophy and proliferation of glial cells. The revealed pathological changes of the synapses were manifested by dilatation of some vesicles and the appearance of heterogenic inclusions. The characteristic features of Wallerian degeneration of callosal synapses and the reversible retrograde changes of the neurons which send their axons into the traumatized zone of the contralateral hemisphere were observed to be similar after both experimental lesions.