Cellular mechanisms of the saccade generating circuit

眼跳发生电路的细胞机制

• 批准号: 6858875
• 负责人: JAMES W GNADT
• 金额: $ 5.87万
• 依托单位: STATE UNIVERSITY NEW YORK STONY BROOK
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-02-01 至 2007-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6858875
• 关键词: action potentials; brain electrical activity; brain imaging /visualization /scanning; brain mapping; brain stem; cell population study; electrophysiology; fluorescence microscopy; genetically modified animals; intracellular; laboratory mouse; laboratory rat; membrane channels; membrane potentials; method development; motor neurons; neural transmission; neuroanatomy; neuropharmacology; saccades; single cell analysis; suid alphaherpesvirus 1; superior colliculus; visual pathways; voltage /patch clamp

DESCRIPTION (provided by applicant): The overall goal of this project is to investigate cellular mechanisms in the premotor neuronal structures of the saccade generating circuit, namely, the excitatory burst neurons (EBN) and the omnipause neurons (OPN). Our first goal in this project is a methodological one: we will attempt to identify these premotor cells using the novel retrograde transynaptic virus labeling technique. Our objective is to obtain a "blueprint" protocol for labeling these higher order neurons in the saccadic circuit. This will be of immense value for neuronal pathway tracing and for answering future electrophysiological questions in conjunction with fluorescent microscopy. A weak strain of the pseudo-rabies virus will be injected into the extraocular muscle for retrograde transmission. A second objective of this project is to investigate specific cellular and synaptic properties of the EBN and OPN cells in the in vitro preparation. Based on published work from our laboratory and elsewhere, we have made several predictions with regard to the cellular properties of these cells. One of them is the presence of post-inhibitory rebound (PIR) in the EBN and OPN that would explain some of the network properties observed in vivo from live behaving animals. These are the "resonance" observed in the EBN cells (Gnadt. et. al., 2001) and the post-saccade enhancement observed in the OPN cells (Gandhi and Keller, 1999). Brain slices from the mouse will be harvested from the brainstem in the region of the nucleus interpositus of Raphe close to the midline. These slices will be maintained under physiological conditions and subjected to voltage and current test protocols designed to investigate the rebound and other properties of the cell. Pharmacological manipulations will enable us to identify and characterize the specific ionic channels underlying these phenomena. Our investigations into these questions will provide data that will further advance our knowledge of the saccadic circuit used by mammals to make quick and accurate eye movements to the target.

描述（由申请人提供）：该项目的总体目标是研究扫视产生电路的前神经元结构中的细胞机制，即兴奋性爆发神经元（EBN）和全肠神经元（OPN）。我们在该项目中的第一个目标是方法：我们将尝试使用新型逆行透射性病毒标记技术来识别这些前运动细胞。我们的目的是获得“蓝图”方案，用于标记saccadic电路中的这些高阶神经元。这对于神经元途径追踪和与荧光显微镜结合回答未来的电生理问题将具有巨大的价值。伪兔病毒的弱应变将被注入外部肌肉中，以进行逆行传播。该项目的第二个目标是研究体外制备中EBN和OPN细胞的特定细胞和突触特性。基于我们实验室和其他地方的已发表工作，我们对这些细胞的细胞特性做出了一些预测。其中之一是EBN和OPN中存在抑制后反弹（PIR），这些反弹（PIR）可以解释来自活体动物的体内观察到的一些网络性能。这些是在EBN细胞中观察到的“共振”（Gnadt。Et。，2001）和在OPN细胞中观察到的射击后增强（Gandhi和Keller，1999）。小鼠的脑切片将从靠近中线的Raphe核核核核区域的脑干中收获。这些切片将保持在生理条件下，并经过旨在研究细胞的反弹和其他特性的电压和当前测试方案。药理学操纵将使我们能够识别并表征这些现象基础的特定离子通道。我们对这些问题的调查将提供数据，以进一步提高我们对哺乳动物使用的Saccadic电路的了解，以快速准确地向目标移动。