COORDINATION OF AUTONOMIC AND BEHAVIORAL THERMOREGULATORY RESPONSES DURING EXPOSURE TO A NOVEL STIMULUS IN RATS

The induction of psychological stress in rats is accompanied by an ele vation of core temperature. Our experiments were carried out to determ ine whether the latency, duration, magnitude, or effector mechanisms o f the core temperature response to psychological stress would be alter ed when rats were allowed to use behavioral as well as autonomic therm oregulation. Core temperature, oxygen consumption, and ambient tempera ture were measured in adult rats before and after handling and a sham intraperitoneal injection. Seven rats were studied in a thermocline (g radient of 7 to 42 degrees C) and eight rats were studied in a metabol ic chamber (25 degrees C). The rats studied in the thermocline selecte d a warm ambient temperature following the sham intraperitoneal inject ion and exhibited an increase in core temperature of shorter latency, greater magnitude, and greater duration than those studied in the meta bolic chamber. The rats studied in the metabolic chamber exhibited an oxygen consumption response of greater magnitude and duration than the animals studied in the thermocline. Thus the characteristics in addit ion to the effector mechanisms of the core temperature response to psy chological stress are altered when rats are allowed to use behavioral as well as autonomic thermoregulatory effecters.