Effect of a unilateral cortical lesion on the monoamine content in the cat brain

The serotonin and noradrenalin content in the cerebral cortex, hypothalamus, and mesencephalon was investigated spectrofluorometrically in 12 cats on the 5th-6th day after the production of a pathological focus in the region of the occipital cortex. Diffuse changes of brain activity were recorded on the EEG at this period: spike-like waves and slow waves of increased amplitude. A considerable increase in the serotonin concentration was observed in the cortex, with the effect predominant in the region immediately adjacent to the pathological focus. A tendency for the serotonin level to fall was observed in the hypothalamus and mesencephalon. The noradrenalin concentration in these brain structures showed no significant change. The role of serotoninergic structures of the brain in the mechanisms responsible for restoring the functional state of the brain after experimental injury is discussed.