PHYSIOLOGY OF CIRCANNUAL RHYTHMS

这项研究评估了几种生理学因素的影响。 刺激金背地松鼠的昼夜节律， 包括体内内源性年周期波动的作用 温度对昼夜节律组织的年变化的影响， 代谢率 体温下降通常与 随着冬眠季节的到来， 昼夜节律夹带和代谢率的年际变化 测定 产前光周期在时间/世代中的作用 的周年节律的年轻松鼠也将被检查， 松鼠要么保持在恒定的光照下，以消除光周期线索， 或模拟妊娠期间的自然光周期。 的定时和/或 在这些雌性的后代中， 考察 睾酮（T）抑制冬眠的神经部位 将在植入含有T的插管的雄性松鼠中进行检查 进入含有T受体的神经部位， 体温调节 视交叉上核的抑制作用 (SCN)在雄鸟冬眠和繁殖的年际周期中 将对松鼠进行检查，以确定这个细胞核是否起作用。 在雄性和雌性中也是如此，以限制冬眠和繁殖 一年中的特定时间。 这项研究可能有助于开发 治疗人类疾病的干预措施， 基础

The proposed research evaluates the impact of several physiological stimuli on circannual rhythms of golden-mantled ground squirrels, including the role of endogenous circannual fluctuations in body temperature on circannual variations in circadian organization and metabolic rate. The decrease in body temperature normally associated with the hibernation season will be blocked and the presence of circannual variations in circadian entrainment and metabolic rate determined. The role of prenatal photoperiod in the timing/generation of circannual rhythms of young squirrels will also be examined in squirrels kept either in constant light, to eliminate photoperiod cues, or a simulated natural photoperiod during gestation. The timing and/or presence of circannual rhythms in the offspring of these females will be examined. Neural sites at which testosterone (T) suppresses hibernation will be examined in male squirrels implanted with cannulae containing T into neural sites that contain T receptors and implicated in thermoregulation. The inhibitory role of the suprachiasmatic nucleus (SCN) in circannual timing of hibernation and reproduction in male squirrels will be examined to determine if this nucleus functions similarly in males as in females to limit hibernation and reproduction to particular times of year. This research may help in the development of interventions for treating human disorders that have a circannual basis.