Behavior-driven monitoring of thermogenesis in mice using a thermal gradient ring.

Abstract

Accurately assessing whole body heat production requires reliable thermometry methods. In mice, common approaches include rectal temperature (RT) measurement, infrared (IR) thermography, and implanted probes. However, factors such as stress, handling, surgery, and variability limit their applicability for evaluating thermogenesis. The Thermal Gradient Ring (TGR), widely used in neuropathic pain and ion channel studies, consists of a circular structure with 12 temperature zones and an integrated camera for real-time behavior monitoring. This system allows for precise analysis of independent behavioral measures, including preferred temperature (PT), distance accumulation in the zones, locomotion pattern, and zone occupancy over time, thereby offering an indirect readout of thermoregulatory state. In this study, we evaluated TGR as a noninvasive tool to detect thermoregulatory behavior adaptations, quantifying zone occupancy time, mobility patterns across temperature gradients, and preferred temperature. Using models with both elevated (β-adrenergic stimulation and high-fat diet feeding) and reduced core body temperature [brown adipose tissue (BAT) lipectomy, uncoupling protein 1 (UCP1) deficiency, and cold exposure], we found that the TGR system reliably detects context-specific thermoregulatory behaviors that contribute to energy homeostasis, while simultaneously serving as a quantitative tool for evaluating thermogenic status. These findings suggest that TGR is a valuable tool for metabolic research, offering a reliable additional assessment for thermogenesis in mice.NEW & NOTEWORTHY The integration between adaptive thermogenesis and behavioral strategies governing metabolic state regulation in mice remains poorly characterized. Using a TGR system, we developed and validated a novel methodology for noninvasive, unbiased, and continuous monitoring of behavior-driven thermogenic capacity. Using loss- and gain-of-function models of BAT thermogenesis, we identified distinct behavioral strategies, mice dynamically adjusted locomotor activity and thermal zone occupancy to modulate heat production, directly reflecting their real-time monitoring of metabolic status.