[The influence of the posterior hypothalamus on the visual cortex in different states of the reticular formation].

In alert rabbits, stimulation of posterior hypothalamus induced short-latency responses in the visual cortex and affected the formation of the EPs to light. Depending on the intervals between the stimuli, either initial extinction of the EPs (1-15 msec) or subsequent selective facilitation of its positive component with simultaneous depression of negative (20-100 msec) one, or complete recovery of the response (200-300 msec), were observed. Aminazine and benactizine made the effect of the posterior hypothalamic stimulation on visual EPs to light less obvious and changed its dynamics. Other findings suggested an inhibitory effect of the mesencephalic RF on the activity of hypothalamo-cortical input. A role of phasic mechanism of hypothalamic control in realization of visual cortex's perceptive function, is discussed.