NOREPINEPHRINE AND ATTENTIONAL MODULATION OF CORTEX

描述(申请人摘要)：顶叶皮质是一种视觉 表示空间关系的区域。此表示法具有 已经被证明依赖于人类和非人类的注意力状态 灵长类动物。在后一种物种中，电生理测量 反复证明“注意力”可以改变单个细胞的反应 在顶叶下小叶。很少有研究研究 生理机制是调节视觉反应的基础。 理解的空隙并不局限于顶叶皮质，因为 其他皮质也存在类似的问题。目前的提案将是 第一个使用精确的神经药理学方法来解决 大脑皮层视觉反应的注意调节问题 表现得像猴子一样。这一方法将分为三个方面。行为上的， 电生理学和神经药理学方法将结合起来 为了研究蓝斑弥漫投射如何 改变大脑皮层反应。主要的假设是去甲肾上腺素 释放是顶叶神经活动注意调节的基础 大脑皮层。具体来说，去甲肾上腺素的释放随蓝斑的不同而不同。 改变个人信噪比处理能力的活动 锥体神经元和中间神经元的功能回路。为了测试 在这种假设下，猴子将被训练执行一项行为任务 其中难度和注意力的注意维度可能是 有系统地操纵。实力和空间分布 的神经表示将被定量地评估为 使用单一单位记录方法的注意状态的功能。 然后，将使用微渗析来测量细胞外去甲肾上腺素 级别。将进行药理操作以确认 去甲肾上腺素正在这个地方被释放。然后，去甲肾上腺素 将测量在不同注意状态下的释放。相关性 将电生理学和药理学之间的关系 措施。恢复注意力缺陷的策略可能会衍生出来 从这项工作中。

DESCRIPTION (Applicant's abstract): The parietal cortex is a visual region that represents spatial relationships. This representation has been shown dependent on attentional state in both human and non-human primates. In the latter species, electrophysiological measurements have repeatedly shown that "attention" can alter the response of single cells in the inferior parietal lobule. Few studies have examined what physiological mechanisms underlie the modulation of the visual response. The lacuna in understanding is not limited to the parietal cortex as similar issues exist for other cortices. The current proposal will be the first to use precise neuropharmacological methods to address the issue of attentional modulation of visual responses in the cortex of behaving monkeys. The approach will be three-fold. Behavioral, electrophysiological and neuropharmacological methods will be combined in order to examine how the locus coeruleus diffuse projections may alter cortical responses. The primary hypothesis is that norepinephrine release underlies attentional modulation of neural activity in parietal cortex. Specifically norepinephrine release varies with locus coeruleus activity altering signal-to-noise processing capabilities of individual pyramidal neurons and the functional circuitry of interneurons. To test this hypothesis, monkeys will be trained to perform a behavioral task in which the attentional dimensions of difficulty and focus may be systematically manipulated. The strength and the spatial distribution of the neural representation will be quantitatively evaluated as a function of attentional state using single unit recording methods. Microdialysis will then be used to measure extracellular norepinephrine levels. Pharmacological manipulations will be performed to confirm that norepinephrine is being released at this site. Then, norepinephrine release at different attentional states will be measured. Correlations will be drawn between the electrophysiological and pharmacological measures. Strategies for restoring attentional deficits may be derived from this work.