Objective classification of motion- and direction-sensitive neurons in primary somatosensory cortex of awake monkeys.
Objective classification of motion- and direction-sensitive neurons in primary somatosensory cortex of awake monkeys.
复制标题
清醒猴初级体感皮层运动和方向敏感神经元的客观分类。
DOI：
10.1152/jn.1986.56.3.598
复制
发表时间：
1986
影响因子：
2.5
通讯作者：
Gardner,EP
中科院分区：
文献类型：
--
作者：
Warren,S;Hamalainen,HA;Gardner,EP
为了对SI皮层中的运动敏感神经元进行分类，并估计它们的相对分布，我们开发了一种新的简单方法，用于控制皮肤上纹理表面的运动，以及一组用于确定方向选择性的客观标准。使用5 mm厚的精密齿轮产生移动刺激，齿轮的齿形成移植物。它们被安装在低扭矩电位器的轴上（以测量运动的速度和方向），并使用电位器轴作为轴在皮肤上手动滚动。当移植轮前进时，其脊依次接触皮肤上的一组特定点，留下未受刺激的限定间距的间隙。这种刺激是可重复的，从试验到试验，并产生小的皮肤扩张。使用三个客观标准对反应进行分类：对最喜欢和最不喜欢的方向上的运动的反应的比率[方向指数（DI）]，两个方向上的平均放电率之间的差异除以平均标准差[可辨别性指数（delta 'e）]和统计检验。如果DI大于35，delta大于或等于1.35（相当于无偏观察者的75%正确辨别率），并且在最优选和最不优选方向上的放电率显著不同（P小于0.05），则神经元被归类为方向敏感。三种分类方案之间存在良好的一致性。记录来自5只猕猴的初级体感皮层（3b区、1区和2区）的手和前臂区域的1,020个皮层神经元。发现皮肤上的切向运动对SI皮层神经元是一种非常有效的刺激。757个触觉神经元中有286个（38%）对移动刺激的反应比对压力或敲击皮肤的反应更强烈。121个细胞进行了测试与移动光栅，并根据他们的能力，区分运动在纵向和横向方向进行分类。对移动光栅的反应类似于用刷子、边缘或钝探针抚摸皮肤时观察到的反应。发现三种主要类型的放电模式：运动敏感，方向敏感和方向敏感。运动敏感神经元（37%）对纵向和横向运动都有反应，但放电频率和间隔分布略有不同。整个领域的反应是相当一致的，并没有明确的最高灵敏度是显而易见的。方向敏感神经元（60%）对一个或多个方向的运动表现出明显的偏好。
In order to classify movement-sensitive neurons in SI cortex, and to estimate their relative distribution, we have developed a new simple method for controlled motion of textured surfaces across the skin, as well as a set of objective criteria for determining direction selectivity. Moving stimuli were generated using 5 mm thick precision gear wheels, whose teeth formed a grafting. They were mounted on the shafts of low-torque potentiometers (to measure the speed and direction of movement) and rolled manually across the skin using the potentiometer shaft as an axle. As the grafting wheel was advanced, its ridges sequentially contacted a specific set of points on the skin, leaving gaps of defined spacing that were unstimulated. This stimulus was reproducible from trial to trial and produced little distention of the skin. Three objective criteria were used to categorize responses: the ratio of responses to motion in the most and least preferred directions [direction index (DI)], the difference between mean firing rates in the two directions divided by the average standard deviation [index of discriminability (delta'e)], and statistical tests. Neurons were classified as direction sensitive if DI greater than 35, delta's greater than or equal to 1.35 (equivalent to 75% correct discrimination by an unbiased observer), and firing rates in most- and least-preferred directions were significantly different (P less than 0.05). Good agreement was found between the three classification schemes. Recordings were made from 1,020 cortical neurons in the hand and forearm regions of primary somatosensory cortex (areas 3b, 1 and 2) of five macaque monkeys. Tangential motion across the skin was found to be an extremely effective stimulus for SI cortical neurons. Two hundred eighty six of 757 tactile neurons (38%) responded more vigorously to moving stimuli than to pressure or tapping the skin. One hundred twenty-one cells were tested with moving gratings and were classified according to their ability to differentiate movement in longitudinal and transverse directions. Responses to the moving gratings resembled those observed when stroking the skin with brushed, edges, or blunt probes. Three major types of firing patterns were found: motion sensitive, direction sensitive, and orientation sensitive. Motion-sensitive neurons (37%) responded to movement in both longitudinal and transverse directions with only slight difference in firing rates and interval distributions. Responses throughout the field were fairly uniform, and no clear point of maximum sensitivity was apparent. Direction-sensitive neurons (60%) displayed clear preferences for movement in one or more directions.4