BEHAVIOR, BIOLOGICAL RHYTHMS AND BRAIN

描述（申请人摘要）：本提案旨在增强 理解昼夜视觉的完整结构和功能 系统研究工作分为四个部分。第一个问题涉及 功能神经解剖学，重点是昼夜节律系统调节， 血清素这些研究将确定是否在大脑中的多巴胺能神经元， 中缝核或中缝背核调节昼夜节律相位反应， 抑制SCN中光诱导的FOS-IR。第二节包括 旨在评估皮层下视觉的贡献的实验 生理节律调节系统。实验将评估的作用， 膝状体间小叶和深上级丘，以确定其 作为对紧张性光刺激的节律反应的介质的作用。电 刺激上级丘的深层也将用于 进一步确定该区域如何参与昼夜节律相位控制 和FOS-IR在SCN中的表达。最后一节包括基本的 将使用顺行和逆行追踪的神经解剖学研究， a）IGL和VLG投影的模式 腹侧和尾侧中脑;和B）相互的多巴胺能神经， 位于中缝背核和正中核之间的GABA能或其他神经支配。我们 我也将学习共聚焦显微镜，并开始研究 存在GABA能SCN神经元的视网膜神经支配， 光诱导的FOS-IR神经元核。 这些研究将使用免疫组织化学技术，示踪剂应用， 离子电渗疗法，电脑刺激以引起节律相移，以及 运动活动的昼夜节律性的测量， 计算机收集的数据记录。研究结果将大大扩展对 仓鼠昼夜视觉节律系统的结构和功能。

DESCRIPTION (applicant's abstract): This proposal is designed to enhance understanding of the full structure and function of the circadian visual system. The research effort is divided into four parts. The first concerns functional neuroanatomy, with emphasis on circadian system regulation by serotonin. These studies will determine whether serotonergic neurons in the median or dorsal raphe nuclei regulate circadian rhythm phase response or inhibition of light-induced FOS-IR in the SCN. Section two consists of experiments designed to evaluate the contribution of the subcortical visual system to circadian rhythm regulation. Experiments will evaluate the role of the intergeniculate leaflet and deep superior colliculus to determine their role as mediators of rhythm response to tonic light stimulation. Electrical stimulation of the deep layers of the superior colliculus will also be used to further determine how this area participates in circadian rhythm phase control and expression of FOS-IR in the SCN. The final section consists of basic neuroanatomy studies that will use anterograde and retrograde tract tracing and double label techniques to determine a) the patterns of IGL and VLG projections to the ventral and caudal midbrain; and b) the reciprocal serotonergic, GABAergic or other innervation between the median and dorsal raphe nuclei. We will also learn confocal microscopy and begin studying the extent to which there is retinal innervation of GABAergic SCN neurons that also contain light-induced FOS-IR neuronal nuclei. The studies will use immunohistochemical techniques, tracer application with iontophoresis, electrical brain stimulation to elicit rhythm phase shifts, and measurement of circadian rhythmicity of locomotor activity with computer-collected data records. The results will greatly expand understanding of the structure and function of the hamster circadian visual rhythm system.