FUNCTIONAL ORGANIZATION OF THE FRONTAL EYE FIELD

描述(改编自申请人的摘要)：建议的实验 继续研究灵长类前额的功能组织 眼场皮层及其在自愿眼执行中的作用 动静。FEF(FEFsac)跳动区神经元的研究进展 查找与扫视、视觉输入和 眼睛的位置以及包括记忆和预期在内的行为状态； 在FEF的流畅的眼睛里也可以发现与流畅追逐相关的类似活动 运动区(FEFsem)。这项新的提案启动了一项调查， 这些活动和信息在FEF和其他地区之间进行交流 与FEF有很强的相互联系，表现为动眼 功能，以及电刺激眼球运动的低阈值。这个 位于顶内沟外侧岸的顶眼视野 (LIP)将是研究的主要结构。据推测，FEF 从PEF接收编码可能的扫视目标的视觉空间信息， 并且PEF接收来自 FEF。前额叶与丘脑背侧动眼运动区之间的交通 (称为丘脑眼场；TEF)将是另一对被研究的对象。它是 假设FEF收到正在执行和已完成的传出副本 TEF的眼球跳动及其向TEF接力的传出 关于即将发生的眼球跳动的信息。对于每对配对 (PEF&lt；-&gt；FEF和TEF&lt；-&gt；FEF)，将执行6个补充实验 目的：1)确定FEF通过以下方式向每个目标区域发送哪些信息/信号 FEF神经元被电极逆行激活的特征 PEF和TEF。2)通过以下方式来表征FEF从PEF和TEF接收的信息 反向使用相同的方法。3)分析区域间通信 通过同时记录具有重叠响应场的神经元 FEF和目标区域，并分析可能的因果关系，通过 它们在不同行为期间尖峰的交叉相关图。4)至 通过直接刺激FEF来补充互相关分析 用极低强度脉冲(1-10帕)在低频下记录神经元 (1-3 Hz)，并检测PEF/TEF神经元的刺激后直方图(PSTH) 对于显著的兴奋作用。PEF/TEF对FEF神经元的直接激活作用 网站将通过相同的方法进行反向审查。5)进一步测试 目标3或4通过使推定的 毒蝇酚或利多卡因的效应点及功能再分析 假定靶点的神经元的特性。6)提供罚款 通过微量注射BDA对这些相互联系的解剖细节 和其他示踪剂，在生理特征的部位，在FEF和 PEF或TEF。 因此，这项提案的总体目标是开始描述 中脑上方的分布式网络的协调 自愿的眼球运动。最终目标是将这些数据统一在 准确区分正常与异常的FEF函数模型 感觉运动行为，并解释了预测性、助记性和认知性 FEF函数的小平面。

DESCRIPTION (Adapted From The Applicant's Abstract): The proposed experiments continue an investigation of the functional organization of the primate frontal eye field (FEF) cortex and its role in the execution of voluntary eye movements. Previous studies of neurons in the saccadic region of FEF (FEFsac) find different combinations of activity related to saccades, visual inputs, and eye position as well as to behavioral states including memory and anticipation; similar activities related to smooth pursuit are found in FEF's smooth eye movement region (FEFsem). This new proposal initiates an investigation of how such activities and information are communicated between FEF and other areas that have strong reciprocal connections with FEF, demonstrated oculomotor function, and low thresholds for electrically eliciting eye movements. The parietal eye field (PEF) Iying in the lateral bank of the intraparietal sulcus (LIP) will be the principal structure studied. It is hypothesized that FEF receives visuospatial information coding possible saccadic targets from PEF, and that PEF receives activity coding impending saccadic eye movements from FEF. Communications between FEF and the oculomotor zone of the dorsal thalamus (termed thalamic eye field; TEF) will be the other pairing studied. It is hypothesized that FEF receives efferent copies of executing and completed saccadic eye movements from TEF, and that FEF efferents to TEF relay information about impending saccadic eye movements. For each of the pairings (PEF<->FEF and TEF<->FEF), 6 complementary experiments will be executed which Aim: 1) To determine what information/signals FEF sends to each target area by characterizing FEF neurons that are antidromically activated by electrodes in PEF and TEF. 2) To characterize information FEF receives from PEF and TEF by using the same methodology in reverse. 3) To analyze interareal communications by simultaneously recording from neurons with overlapping response fields in FEF and a target area, and analyzing possible causal relationships via cross-correlograms of their spiking during different behaviors. 4) To complement the cross-correlation analyses by directly stimulating the FEF neuron being recorded with very low-intensity pulses (1-10 pA) at low frequency (1-3 Hz) and examining post-stimulus histograms (PSTHs) of the PEF/TEF neuron for significant excitation. Direct activation of the FEF neuron by the PEF/TEF site will be examined via the same methodology in reverse. 5) To further test any causal relation indicated by Aims 3 or 4 by deactivating the presumed effector site with muscimol or lidocaine and reanalyzing the functional properties of the neuron at the presumed target site. 6) To provide fine anatomical details of these reciprocal connections via microinjections of BDA and other tracers at physiologically-characterized sites, both in FEF and in PEF or TEF. Thus, the overall objective of this proposal is to begin to characterize the coordination of the distributed network above the midbrain that directs voluntary eye movements. The ultimate objective is to unite such data within a model of FEF function that accurately relates to normal and abnormal sensorimotor behavior, and accounts for the predictive, mnemonic, and cognitive facets of FEF function.