[Effect of single stimuli to the posterior hypothalmus on the visual evoked potentials of an anesthetized rabbit]

Single stimuli applied to the posterior hypothalamus evoke in the visual cortex of anesthetized rabbits a hypothalamic--cortical response with short latency, marked premarily--positive and negative components, and secondary positive wave of a large amplitude. It seems that projections from the posterior hypothalamus to the cortex are multiple, pass through different subcortical structures and terminate with different synaptic organizations. Single stimuli applied to the posterior hypothalamic nuclei with intervals from 700 to 100 msec facilitate a visual evoked potential due to enhancement of the negative component. Apart from the facilitation of the visual response, the area where the potential can be recorded is enlarged by single stimuli applied to the posterior hypothalamic nuclei.