Body temperature regulates glucose metabolism and torpid behavior

Area of Science:

• Metabolic regulation
• Neuroendocrinology
• Physiology

Background:

• Glucose homeostasis is critical for mammalian physiological activities, including thermoregulation.
• While ambient temperature influences glucose metabolism, the role of body temperature itself remains less understood due to robust thermoregulation.
• Activating preoptic area Qrfp neurons induces hypothermia and hypometabolism (QIH), offering a model to study metabolic changes under reduced body temperature.

Purpose of the Study:

• To investigate the role of body temperature in regulating glucose metabolism and behavior.
• To determine if Q-neuron-induced hypothermia and hypometabolism (QIH) affects insulin sensitivity and metabolic state.
• To elucidate the relationship between Qrfp neuron activation, hypothermia, and metabolic/behavioral changes.

Main Methods:

• Induction of Q-neuron-induced hypothermia and hypometabolism (QIH) in mice via Qrfp neuron activation.
• Monitoring glucose metabolism, insulin levels, and insulin resistance in QIH mice.
• Comparing metabolic and behavioral parameters between hypothermic (QIH) and euthermic states.

Main Results:

• Mice in a QIH state exhibited hyperinsulinemia and insulin resistance.
• Restoring normal body temperature (euthermia) abolished the glucose hypometabolic state in QIH mice.
• QIH-associated inappetence and reduced locomotor activity were reversed upon returning to euthermia.

Conclusions:

• Body temperature exerts a more potent influence on glucose metabolism and behavior than ambient temperature.
• The observed glucose hypometabolism in QIH is a consequence of hypothermia, not directly modulated by Qrfp neuron activity.
• Thermoregulation plays a crucial role in maintaining metabolic and behavioral homeostasis.