CONTROL OF CENTRAL VISUAL PATHWAYS BY THE BRAINSTEM

脑干对中央视觉通路的控制

• 批准号: 2391687
• 负责人: DANIEL J UHLRICH
• 金额: $ 11.39万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2391687
• 关键词: behavioral /social science research tag; brain electrical activity; brain stem; cats; electrophysiology; histamine; histology; lateral geniculate body; neural information processing; neural inhibition; neuroanatomy; neurophysiology; psychophysics; serotonin; synapses; visual feedback; visual pathways; visual perception; visual stimulus

DESCRIPTION (from the investigator's abstract): Retinal signals destined for the visual cortex for conscious perception must first pass through the lateral geniculate nucleus (LGN) of the thalamus. The afferent signals from the eye are not relayed unchanged to cortex; instead, they are actively gated and modified in the LGN. Cortical processing must depend critically on the nature of the signals that provide cortical input. Our long-term goal is to understand the full spectrum of action that the LGN is capable of enacting on cortically-directed signals, and thus to more fully understand the role of this important neural structure in vision. We believe that the spatial and temporal characteristics of visual signals are modulated in the LGN as a function of the behavioral condition. These studies will enable us to compare the modulation in the LGN that is controlled in the awake state by three fundamentally different projections from the brainstem and hypothalamus: the serotonergic, histaminergic, and previously-studied cholinergic system. While we and others have revealed the existence, anatomy and pharmacology of these systems, it is not clear how each system alters the visual signal that is transmitted to cortex. In vitro studies indicated that these systems share a common method of directly exciting cortically-projecting relay cells, but they have radically different effects on geniculate inhibitory cells, which critically shape important features of LGN cell physiological responses. Thus, we propose that each modulatory system will very differently sculpt the visual signals that are transmitted to cortex. In Specific Aim #1, we will determine how the histaminergic and serotonergic systems alter the visual response of geniculate neurons. In contrast to the known effects of the cholinergic system, which are primarily disinhibitory on LGN relay cells, we predict that activation of the histaminergic system, and even more so, the serotonergic system will strengthen the inhibition-dependent characteristics of the visual responses. In Specific Aim #2, we will determine how these systems combine to alter visual responses in LGN neurons, because all are active in the awake state. We will accomplish these aims by recording in vivo the responses of LGN neurons to sophisticated visual stimuli during specific neuromodulatory activation.

描述(摘自研究人员摘要)：视网膜信号 因为有意识感知的视觉皮质必须首先通过 丘脑外侧膝状体(LGN)。传入者 来自眼睛的信号不会原封不动地传递到大脑皮层；相反，它们 在LGN中被主动选通和修改。皮质处理必须 严重依赖于提供大脑皮质的信号的性质 输入。我们的长期目标是了解所有行动的范围 LGN能够对大脑皮层定向信号起作用，以及 从而更充分地了解这一重要神经的作用 视觉中的结构。我们认为空间和时间 视觉信号的特性在LGN中作为函数被调制 他的行为状况。这些研究将使我们能够比较 在唤醒状态中被控制三倍的LGN中的调制 来自脑干和下丘脑的截然不同的投射： 5-羟色胺能、组胺能和先前研究的胆碱能 系统。当我们和其他人揭示了人类的存在、解剖和 这些系统的药理学，还不清楚每个系统是如何改变的 传递到大脑皮质的视觉信号。体外研究 表示这些系统共享一种共同的直接激励方法 皮质投射的中继细胞，但它们有根本不同的 对膝曲抑制细胞的影响，这对塑造重要的 LGN细胞生理反应的特点。因此，我们建议每个 调制系统将以非常不同的方式塑造视觉信号 传输到大脑皮层。在具体的目标1中，我们将确定如何 组胺和5-羟色胺能系统改变视觉反应 膝状神经元。与已知的胆碱能药物的作用相反 系统，这主要是对LGN中继细胞的抑制，我们预测 组胺能系统的激活，更是如此， 5-羟色胺能系统将加强抑制依赖 视觉反应的特征。在具体目标2中，我们将 确定这些系统如何组合以改变LGN的视觉反应 神经元，因为所有神经元在清醒状态下都是活跃的。我们将完成 这些目的是通过在体内记录LGN神经元对 在特定神经调节激活过程中复杂的视觉刺激。