[Response of neurons of the anterior and posterior regions of the hypothalamus to stimulation of the vagus and sciatic nerves and photic stimulation]

Abstract

Evoked activity of single units in anterior and posterior hypothalamus to vagal, sciatic nerves, and photic stimulation was studied in anesthetized and immobilized cats. The responsiveness of neurons of the posterior hypothalamus was 66, 77 and 37% to vagal, sciatic nerves and photic stimulation, respectively, and of the anterior hypothalamus -- 47, 62 and 48%. Vagal stimulation was found to be the more effective for units of the posterior hypothalamus. Responses of units to a flash prevailed in the anterior hypothalamus. 78% of convergence of viscero-somatic afferentation on neurons of the posterior hypothalamus and 62% -- on anterior hypothalamic neurons, were revealed. The responses to all kinds of afferent stimuli were phasic and of excitatory character. Possible role and mechanisms of vagal interoceptive activation of hypothalamic units are discussed.