PHOTIC ENTRAINMENT OF CIRCADIAN BEHAVIORS

描述（改编自申请人的摘要）：该项目将 研究神经化学信号如何在SCN内相互作用， 昼夜节律与昼夜周期的行为。 由于疾病的 昼夜节律计时系统已经与各种心理 疾病，了解昼夜节律的神经生物学应该导致 对这些疾病的新疗法的发展。 至少三 SCN的不同传入投射参与了光的传导， 昼夜节律的诱导。 RHT是一个直接的投影， 视网膜是必要的和足够的夹带。 投射 中缝和膝状体间小叶对SCN也有影响 虽然它们不提供夹带所需的输入 过程 这些传入投射中包含的神经化学信号 以及SCN固有的神经元以复杂的方式相互作用， 控制光夹带。 该项目的长期目标是确定 通过定义昼夜节律的神经化学基础 光信息如何被传送到SCN并在SCN内被处理。 具体目标我将检验EAA是一种神经递质的假设 其通过RHT将光信息传送到SCN。 以来 研究者已经能够证明注射EAA激动剂 (i.e., NMDA）进入SCN中可以模拟 光，这将有可能解决一个重大的差异， 假说. 具体目标2将检验P物质的假设， 似乎包含在RHT中，通过以下方式促进夹带 调节SCN中EAA的活性。 第3章调查 光的相移效应如何受到内在SCN的影响 电路和SCN的传入投射。 具体而言是 研究者将检验GABA、血清素和NPY抑制 通过抑制光的相移效应 SCN中的EAA和/或物质P。

DESCRIPTION (Adapted from applicant's abstract): This project will investigate how neurochemical signals interact within the SCN to synchronize circadian rhythms in behavior with the day-night cycle. Since disorders of the circadian timing system have been linked to a variety of mental illnesses, understanding the neurobiology of circadian rhythms should lead to the development of new treatments for these diseases. At least three different afferent projections of the SCN are involved in the photic entrainment of circadian rhythms. The RHT is a direct projection from the retina that is necessary and sufficient for entrainment. Projections from the raphe and the intergeniculate leaflet to the SCN also influence entrainment although they do not provide input necessary for the entrainment process. The neurochemical signals contained in these afferent projections as well as in neurons intrinsic to the SCN interact in a complex manner to control photic entrainment. The long-term goal of this project is to define the neurochemical basis of the entrainment of circadian rhythms by defining how photic information is communicated to and processed within the SCN. Specific Aim I will test the hypothesis that an EAA is a neurotransmitter which communicates photic information to the SCN through the RHT. Since the investigator has been able to demonstrate that injection of an EAA agonist (i.e., NMDA) into the SCN in vivo can mimic the phase shifting effects of light, it will be possible to resolve a significant discrepancy about this hypothesis. Specific Aim 2 will test the hypothesis that substance P, which appears to be contained in the RHT, contributes to the entrainment by modulating the activity of EAAs in the SCN. Specific Aim 3 will investigate how the phase shifting effects of light are influenced by intrinsic SCN circuits and by afferent projections of the SCN. Specifically, the investigator will test the hypothesis that GABA, serotonin and NPY inhibit the phase shifting effects of light by inhibiting the phase shifting effects of EAAs and/or substance P in the SCN.