Fig 3 Data.

Neurons in the hypothalamic preoptic area (POA) regulate multiple homeostatic processes, including thermoregulation and sleep, by sensing afferent input and modulating sympathetic nervous system output. The POA has an autonomous circadian clock and may also receive circadian signals indirectly from the suprachiasmatic nucleus. We have previously defined a subset of neurons in the POA termed QPLOT neurons that are identified by the expression of molecular markers (Qrfp, Ptger3, LepR, Opn5, Tacr3) that suggest receptivity to multiple stimuli. Because Ptger3, Opn5, and Tacr3 encode G-protein coupled receptors (GPCRs), we hypothesized that elucidating the G-protein signaling in these neurons is essential to understanding the interplay of inputs in the regulation of metabolism. Here, we describe how the stimulatory Gs-alpha subunit (Gnas) in QPLOT neurons regulates metabolism in mice. We analyzed Opn5cre; Gnasfl/fl mice using indirect calorimetry at ambient temperatures of 22°C (a historical standard), 10°C (a cold challenge), and 28°C (thermoneutrality) to assess the ability of QPLOT neurons to regulate metabolism. We observed a marked decrease in nocturnal locomotion of Opn5cre; Gnasfl/fl mice at both 28°C and 22°C, but no overall differences in energy expenditure, respiratory exchange, or food and water consumption. To analyze daily rhythmic patterns of metabolism, we assessed circadian parameters including amplitude, phase, and MESOR. Loss-of-function GNAS in QPLOT neurons resulted in several subtle rhythmic changes in multiple metabolic parameters. We observed that Opn5cre; Gnasfl/fl mice show a higher rhythm-adjusted mean energy expenditure at 22°C and 10°C, and an exaggerated respiratory exchange shift with temperature. At 28°C, Opn5cre; Gnasfl/fl mice have a significant delay in the phase of energy expenditure and respiratory exchange. Rhythmic analysis also showed limited increases in rhythm-adjusted means of food and water intake at 22°C and 28°C. Together, these data advance our understanding of Gαs-signaling in preoptic QPLOT neurons in regulating daily patterns of metabolism.下丘脑视前区（hypothalamic preoptic area, POA）内的神经元通过感知传入输入并调控交感神经系统输出，调节包括体温调节与睡眠在内的多种稳态过程。视前区拥有自主昼夜节律钟，同时也可间接接收来自视交叉上核的昼夜节律信号。我们此前已定义了视前区内一类被称为QPLOT神经元的神经元亚群，这类神经元可通过表达Qrfp、Ptger3、LepR、Opn5、Tacr3等分子标志物进行鉴定，提示其可接收多种刺激信号。由于Ptger3、Opn5与Tacr3均编码G蛋白偶联受体（G-protein coupled receptors, GPCRs），我们推测阐明此类神经元内的G蛋白信号通路，对于理解代谢调控中各类输入信号的相互作用至关重要。本研究旨在阐明QPLOT神经元内的刺激性Gsα亚基（Gnas）如何调控小鼠的代谢过程。我们在22℃（常规环境温度标准）、10℃（冷应激环境）与28℃（热中性温度）三种环境温度下，利用间接量热法对Opn5cre; Gnasfl/fl小鼠进行分析，以评估QPLOT神经元调控代谢的能力。我们观察到，在28℃与22℃环境下，Opn5cre; Gnasfl/fl小鼠的夜间活动均显著降低，但能量消耗、呼吸交换以及摄食与饮水总量并无显著整体差异。为分析代谢的日常节律模式，我们评估了包括振幅、相位以及节律中线值（MESOR）在内的多项昼夜节律参数。QPLOT神经元内GNAS功能丧失会导致多项代谢参数出现多处细微的节律变化。我们发现，在22℃与10℃环境下，Opn5cre; Gnasfl/fl小鼠的节律调整后平均能量消耗更高，且呼吸交换随温度的变化更为显著。在28℃环境下，此类小鼠的能量消耗与呼吸交换相位均出现显著延迟。节律分析还显示，在22℃与28℃环境下，小鼠的摄食与饮水的节律调整后均值仅出现小幅升高。综上，本研究的数据增进了我们对视前区QPLOT神经元内Gαs信号通路调控代谢日常节律的理解。