Activities of cat striatal and cortical neurons associated with orienting movements.

1. 为了了解基底神经节控制定向运动的神经元机制，分析了警觉猫在视觉引导下眼动任务相关的尾状神经元的活动模式。大多数被取样的神经元，被认为是中间神经元，显示出与任务的某些方面相关的活动。显示与视觉刺激呈现相关活动的神经元分为两组：显示与刺激的物理方面相关活动的神经元和显示与刺激的行为意义相关活动的神经元。前一组神经元倾向于对视觉刺激的位置有选择性，而后一组神经元没有明确的位置选择性。一些尾状神经元很可能参与了猫定向运动的认知过程。研究了注意力对尾状核诱发眼动的发生率和潜伏期的影响。注意注视视觉刺激时的发生率比偶然保持眼睛位置到同一点时的发生率低，潜伏期长。这表明与注意力相关的皮层活动对负责定向运动的神经元机制有显著影响。用HRP逆行转运的方法研究了向尾状核投射的皮质神经元的分布模式。3 .尾状核头部尾侧部分是电刺激诱导眼球运动的有效部位，它倾向于接受来自边缘皮层和皮层尾侧区域的丰富的与空间知觉有关的传入信号，而吻侧部分则是无效的，它倾向于接受来自吻侧皮层与运动功能有关的传入信号。研究表明，尾状核接收来自皮层广泛区域的传入信息，整合包括认知功能在内的各种信息，并形成定向运动的命令。少

1. In order to understand the neuronal mechanism of the control of orienting movement by the basal ganglia, pattern of activities of caudate neurons associated with a visually-guided eye movement task was analyzed in the alert cat. The majority of sampled neurons, which were supposed to be mostly interneurons, showed activities related to some aspects of the task. Neurons which showed activities related to presentation of visual stimuli were classified into two groups : neurons showing activities related to physical aspects of stimuli and those showing activities related to behavioral meanings of stimuli. Neurons of the former group tended to have selectivity of the position of visual stimuli, while neurons of the latter group did not have clear position selectivity. It is likely that some caudate neurons participate in cognitive processes involved in the orienting movement of the cat.2. Effects of attention on the incidence and latency of the caudate-induced eye movement were investig … More ated. The incidence was less and the latency was longer during attentive fixation of the eye to a visual stimulus than during incidental maintenance of the eye position to the same point. This indicates that cortical activities related to attention exert significant influences over the neuronal machinery responsible for the orienting movement.3. Distribution pattern of cortical neurons projecting to the caudate nucleus was investigated by means of retrograde transport of HRP.Caudal parts of the head of the caudate nucleus, which are effective in inducing eye movements by electrical stimulation, tended to receive abundant afferents from the limbic cortex and caudal regions of the cortex which are supposed to be involved in spatial perception, while rostral parts, which are ineffective, tended to receive afferents from rostral cortical areas related to motor functions.4. It is suggested that the caudate nucleus receives afferents from broad areas of the cortex, integrates a variety of information including that related to cognitive function and forms commands for the orienting movement. Less