Cortical and hypothalamic influences on single neurons of mesencephalic reticular formation

Abstract

1. A study of activity of mesencephalic reticular neurons has shown that different influences can converge on them. However, 20% of reticular neurons responded to none of the stimuli used. Nonresponding reticular neurons were characterized either by a high firing rate or by the exceptionally regular character of their activity. 2. Mesencephalic reticular neurons responding to stimuli were chiefly excited by corticofugal impulses from the first sensorimotor area and inhibited by influences from the lateral parts of the posterior hypothalamus. 3. In combined cortico-thalamic influences on the activity of mesencephalic reticular neurons, the dominant role is played by the hypothalamus.