Feeding and drinking elicited by low and high frequencies of hypothalamic stimulation

Rats had chronic, stimulating electrodes implanted in the hypothalamus. Feeding and drinking were elicited in a number of the animals and the occurrence of these consummatory behaviors was shown to be related to the frequency of the hypothalamic stimulation. When the frequency of square wave pulses was 20–40 c/sec feeding was induced more frequently than drinking. As the frequency of the hypothalamic stimulation was raised the occurrence of drinking increased and feeding declined. When the frequencies of stimulation were 100–200 c/sec, drinking was elicited a greater number of times than feeding. It is suggested that signals for water deficit and energy deficit are integrated by neurons in the hypothalamus and other parts of the brain and that these integrative systems are activated differentially by low and high frequencies of electrical stimulation.