Seasonal Plasticity of Brain and Behavior

描述(由申请人提供)：许多物种的个体经历了大脑和行为的季节性变化，这些变化是为了优化繁殖和生存。光周期(日长)被用来确定一年中的时间。褪黑激素由松果体分泌，与夜间长度成正比，它传递光周期信息，引起一系列生理、形态和行为变化，促进越冬生存。海马体体积在短时间内减少，这种形态变化可能是空间学习和记忆季节性缺陷的基础。为了评估光周期通过褪黑素调节行为变化的假设，我们将比较暴露在长或短白天或接受褪黑素治疗的鹿小鼠的行为。这项研究的具体目的是：(1)确定短日照引起的空间学习和记忆障碍是否由褪黑素介导。(2)将这些光周期诱导的缺陷与海马区的结构变化联系起来。(3)确定光周期是否也影响非空间学习和记忆任务。这项研究将为大脑和行为的季节性可塑性机制提供深入的见解

DESCRIPTION (provided by applicant): Individuals of many species undergo seasonal changes in brain and behavior that evolved to optimize reproduction and survival. Photoperiod (day length) is used to determine time of year. Melatonin, secreted from the pineal gland in proportion to night-length, transduces photoperiodic information to evoke a suite of physiological, morphological, and behavioral changes that promote winter-survival. Hippocampal volume decreases in short days, a morphological change that may underlie seasonal deficits in spatial learning and memory. To evaluate the hypothesis that photoperiod mediates behavioral changes via melatonin, we will compare behaviors of deer mice exposed to long or short days or treated with melatonin. The specific aims of the proposed research are: (1) To determine whether short day-induced deficits in spatial learning and memory are mediated by melatonin. (2) To relate these photoperiod-induced deficits to structural changes in the hippocampus. (3) To determine whether photoperiod also affects non-spatial learning and memory tasks. This research will provide insights into the mechanisms of seasonal plasticity of brain and behavior