Autonomic thermoregulation in squirrel monkey when behavioral regulation is limited

Area of Science:

• Physiology
• Behavioral Ecology
• Thermoregulation

Background:

• Squirrel monkeys (Saimiri sciureus) face challenges in cold environments.
• Understanding thermoregulatory strategies is crucial for species survival.

Purpose of the Study:

• To investigate behavioral and autonomic thermoregulation in squirrel monkeys under cold stress.
• To assess the efficiency and vigor of behavioral thermoregulation.

Main Methods:

• Monkeys learned to control chamber air temperature by pulling a chain for thermal reinforcement.
• Preoptic area temperature was manipulated using thermodes to study autonomic responses.
• Metabolic heat production and core/skin temperatures were monitored.

Main Results:

• Behavioral thermoregulation partially controlled chamber temperature but resulted in core temperatures below preferred levels.
• Metabolic heat production increased and was related to the skin-to-air temperature difference.
• Preoptic cooling increased metabolic heat production, while warming reduced it and induced vasodilation.

Conclusions:

• Squirrel monkeys exhibit persistent behavioral thermoregulation, even when suboptimal.
• Autonomic responses supplement behavioral efforts for complete body temperature regulation.
• The study highlights the interplay between behavioral and autonomic control in thermoregulation.