Annual Rhythms of Energy Balance and Behavior

描述（由申请人提供）：总体目标是表征体脂肪储备和下丘脑肽机制，特别是神经肽Y （NPY）在控制日常睡眠中的作用。每日冬眠是温度调节的一种极端形式，通过独特地减少能量消耗来帮助动物应对有限的食物供应。将探讨综合能量平衡和麻木的中枢和外周神经机制。西伯利亚仓鼠（Phodopus sungorus）是所有实验的模式物种，其食物摄取量、体重、繁殖和日常睡眠的年度节律都有很好的记录。具体目的包括：1)对比直接内侧视前区（MPOA）注射NPY对体温的影响，特别是其诱导麻木和影响棕色脂肪组织温度与体温变化时间的能力；2)对西伯利亚仓鼠下丘脑NPY受体亚型分布的解剖学认识；3)比较和对比NPY受体激动剂激活和拮抗剂抑制MPOA中NPY受体位点对睡眠诱导的影响；4)评估MPOA对神经元特异性神经毒性病变诱导（NPY和2DG）和自然麻木的必要性；5)比较和对比下丘脑室旁核直接注射NPY和NPY受体激动剂对肩胛间棕色脂肪组织温度（及体温）的影响。

DESCRIPTION (provided by applicant): The overall goal is to characterize the role that body fat reserves and hypothalamic peptide mechanisms, especially neuropeptide Y (NPY), play in controlling daily torpor. Daily torpor is an extreme form of temperature regulation that evolved to help animals contend with limited food availability by uniquely reducing energy expenditure. The central and peripheral neural mechanisms integrating overall energy balance and torpor will be explored. Annual rhythms of food intake and body mass, reproduction, and daily torpor are well documented in the Siberian hamster (Phodopus sungorus), the model species in all experiments. Specific aims include: 1) contrasting the effects of direct intra-medial preoptic area (MPOA) injections of NPY on body temperature, specifically its ability to induce torpor and affect the timing of changes in brown adipose tissue temperature vs. body temperature; 2) developing an anatomical understanding of the distribution of NPY receptor subtypes in the Siberian hamster hypothalamus; 3) comparing and contrasting NPY receptor agonist activation and antagonist inhibition of NPY receptor sites in the MPOA on torpor induction; 4) evaluating the necessity of the MPOA for both induced (NPY & 2DG) and natural torpor using neuron-specific neurotoxic lesions; 5) comparing and contrasting effects of direct injections of NPY and NPY receptor agonists into the paraventricular nucleus of the hypothalamus on interscapular brown adipose tissue temperature (and body temperature).