Variability of skin temperature in the waking monkey

Area of Science:

• Physiology
• Neuroscience
• Thermoregulation

Background:

• Conscious animals exhibit complex thermoregulatory responses.
• Autonomic nervous system plays a crucial role in maintaining homeostasis.
• Peripheral temperature fluctuations can influence core body temperature.

Purpose of the Study:

• To investigate the relationship between arousal, peripheral temperature, and brain temperature in conscious monkeys.
• To examine the role of autonomic control in regulating peripheral vasomotor tone.

Main Methods:

• Continuous recording of brain, skin, and nasal mucosa temperatures.
• Cortical electroencephalogram (EEG) monitoring in pigtail monkeys.
• Introduction of visual and auditory stimuli to induce arousal.

Main Results:

• Alertness caused rapid drops in peripheral temperatures (22-29°C) from a baseline of 34-37°C.
• Hypothalamic temperature increased by 0.91°C when peripheral areas were cool.
• Barbiturate anesthesia reversed these temperature changes, increasing peripheral and decreasing brain temperatures.

Conclusions:

• Arousal state significantly alters peripheral blood flow and body temperature in monkeys.
• Autonomic nervous system's control over vasomotor tone is critical for thermoregulation.
• Peripheral temperature changes rapidly influence deep body temperature regulation.