EFFECT OF BRAIN-STEM LESIONS ON METRAZOL-INDUCED SEIZURES IN CATS

1. 1. The chronic effect of bilaterally paired lesions in the cat's brain-stem on Metrazol-induced seizures was studied in order to clarify the intracerebral mechanism for the maintenance of epileptic excitability. 2. 2. The results seem to indicate that there are two systems of facilitatory and inhibitory functions in the brain-stem rostral to the pons as far as Metrazol-induced seizure activity is concerned. The facilitatory system consists of the caudal mesencephalon extending rostrally to the posterior hypothalamus through the ventral part of the rostral mesencephalon and posterior sub-thalamus, and also of the medio-dorsal nucleus of the thalamus. the inhibitory system consists of the dorsal part of the rostral mesencephalon extending rostrally to the thalamus and also of the anterior hypothalamus. 3. 3. It may be suggested that this facilitatory system plays a significant role in the onset and generalization of the Metrazol seizure. © 1969.