Effects of electrical stimulation of the hunger center in the lateral hypothalamus and food reinforcement on impulse activity of the proper masticatory muscle in rabbits under conditions of hunger and satiation.

Threshold stimulation of the lateral hypothalamus in starving and preliminary fed (satiated) rabbits in the absence of feed induces searching behavior associated with burst-like impulse activity of proper masticatory muscle with a bimodal distribution of interpulse intervals, what represents an anticipatory type of reaction. The increase in the level of food motivation during threshold stimulation of the lateral hypothalamus in starving and satiated rabbits with the food offered led to successful food-procuring behavior, during which the frequency and amplitude of spike bursts in the proper masticatory muscle become comparable with those under conditions of natural foraging behavior stimulated by the need in nutrients. Motivational excitation and backward afferentation from food reward are addressed to the same neurons of the masticatory center in the medulla oblongata.