Annual Rhythms of Energy Balance and Behavior

描述（由申请人提供）：总体目标是表征体脂储备和下丘脑肽机制，特别是神经肽Y（NPY）在控制日常麻木中的作用。日常休眠是一种极端的温度调节形式，通过独特的减少能量消耗来帮助动物应对有限的食物供应。将探讨整合整体能量平衡和麻痹的中枢和外周神经机制。食物摄入量和体重，繁殖，和每日的麻木的年度节奏在西伯利亚仓鼠（Photopus sungorus），在所有实验的模式物种有很好的记录。具体目标包括：1）对比直接内侧视前区（MPOA）注射NPY对体温的影响，特别是其诱导麻痹和影响棕色脂肪组织温度与体温变化的时间的能力; 2）发展对西伯利亚仓鼠下丘脑中NPY受体亚型分布的解剖学理解; 3）比较和对比MPOA中NPY受体激动剂激活和拮抗剂抑制NPY受体位点对麻痹诱导的影响;（NPY和2DG）和自然麻痹使用神经元特异性神经毒性损伤; 5）比较和对比将NPY和NPY受体激动剂直接注射到下丘脑的室旁核中对肩胛间棕色脂肪组织温度（和体温）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).