Influence of hunger and thirst on the relationship between spontaneous activity and body temperature.

Abstract

Body temperature was recorded continuously in 2 activity devices under ad lib and food or water deprivation conditions. Both hunger and thirst lowered subdermal temperature and increased wheel running, but only food deprivation increased stabilimeter activity. Wheel running produced considerable temperature elevation under all conditions while stabilimeter activity produced only slight and irregular temperature increments. The effects of hunger and thirst on thermoregulat ory behavior were examined in a device which permitted Ss to raise their body temperature without resorting to instrumental or locomotor activity. Both hunger and thirst have a pronounced effect on body temperature, but deprivation-induced changes in running wheel and stabilimeter activity cannot be viewed as surrogate thermoregulatory behaviors. In a previous report (Campbell & Lynch, 1967) data were presented which indicated that body temperature changes are not causally involved in deprivation-induced activity increases. Briefly, it was found that rats housed in high ambient temperatures showed marked increments in wheel running during food deprivation although their body temperatures, as recorded by a continuous monitoring technique, remained within normal ranges during the greater portion of the testing period. These findings are discrepant with the position that body temperature is a major physiological variable underlying the motivational properties of starvation (Brobeck, 1948; Weiss & Laties, 1961) and directly contradict the hypothesis (Stevenson & Rixon, 1957) that spontaneous activity during deprivation is surrogate thermoregulatory behavior. While this research seems to rule out a simple thermostatic •explanation for the activity phenomenon, the problem of specifying the influences of deprivation on the temperature-activity