The cold‐sensing ion channel TRPM8 regulates central and peripheral clockwork and the circadian oscillations of body temperature

• DOI: 10.1111/apha.13896
• Publication Date: 2022-10-17T16:55:22Z
• Authors: Alfonso Reimúndez; Carlos Fernández‐...; Purificación Ordás; Pablo Hernández‐O...; Rosalía Gallego; Cruz Morenilla‐Palao; Juan Navarro; Francisco Martín‐...; José Luís Pardo‐V...; Lindsay A. Schwarz; Victor Arce; Félix Viana; Rosa Señarís
• Keywords: TRPM8; Thermoreceptor

Abstract Aim Physiological functions in mammals show circadian oscillations, synchronized by daily cycles of light and temperature. Central peripheral clocks participate this regulation. Since the ion channel TRPM8 is a critical cold sensor, we investigated its role function. Methods We used reporter mouse lines TRPM8‐deficient mice. mRNA levels were determined situ hybridization or RT‐qPCR protein immunofluorescence. A telemetry system was to measure core body temperature (Tc). Results expressed retina, specifically cholinergic amacrine interneurons subset melanopsin‐positive ganglion cells which project central pacemaker, suprachiasmatic nucleus (SCN) hypothalamus. TRPM8‐positive fibres also found innervating choroid ciliary vasculature, with putative function intraocular temperature, as shown Interestingly, Trpm8 −/− animals displayed increased expression clock gene Per 2 vasopressin (AVP) SCN, suggesting regulatory on oscillator. SCN AVP neurons control studied Tc driven free‐running conditions. TRPM8‐deficiency amplitude oscillations and, under dim constant light, induced greater phase delay instability rhythmicity. Finally, innervate organs, like liver white adipose tissue. Notably, mice dysregulated these metabolic tissues. Conclusion Our findings support sensor involved regulation Tc.