STUDIES ON INTRACRANIAL ELECTRICAL SELF-STIMULATION IN PIGS IN RELATION TO INGESTIVE AND EXPLORATORY-BEHAVIOR

A movable electrode technique was used to locate sites supporting self-stimulation in hypothalamic, substantia nigral and septal regions of young pigs. Increases in current resulted in faster response rates. In animals deprived of food for 22 hr and then satiated before testing, self-stimulation rates decreased in 2 pigs out of 4. Pigs given long-term access to a self-stimulation panel, in a controlled environment, displayed an initial burst of responding lasting several hours but subsequently showed periodic bursts of self-stimulation during 5 days of continuous testing. Pigs given additional operant panels for food and water developed a strong temporal association between self-stimulation and ingestive behaviour. Self-stimulation, delivered by a radio-controlled stimulator, was studied in pigs living outside with access to a hut. Response rates were not affected by restricting exploratory activity and a marked circadian pattern of responding was seen. Stimulation-bound feeding and drinking was elicited in pigs with electrodes in the lateral hypothalamus and operant feeding and drinking was seen in one animal. © 1979.