Topographical patterns of ultrastructural changes in the rat brain during methionine sulphoximine convulsions.

Ultrastructure of the cerebral and cerebellar cortex, hippocampus and nucleus facialis was examined in albino rats during MSO convulsions. Three, 6 and 12 h after peritoneal injection of the drug (600 mg/kg) perfusion and dissection were done. Convulsions appeared 4-5 h, status epilepticus 8-9 h after drug administration. Following the onset of clinical seizures, the mitochondria of the neurons became severely damaged. The vesicles and cisterns of the Golgi complex and the endoplasmic reticulum dilated considerably. In the synapses the vesicles were packed together, their number gradually decreased. The astroglia became highly oedematous. During status epilepticus, dark cells and a thickening of the synaptic membranes could be seen beside the above alterations. The morphological changes were most prominent in the cerebellar cortex and in the h1 area of the hippocampus. The neuronal structure of the cerebral cortex was the least damaged.