RECEPTIVE-FIELD PROPERTIES OF SINGLE UNITS IN OPOSSUM STRIATE CORTEX
RECEPTIVE-FIELD PROPERTIES OF SINGLE UNITS IN OPOSSUM STRIATE CORTEX
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DOI：
10.1016/0006-8993(76)90614-4
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发表时间：
1976-01-01
期刊：
影响因子：
2.9
通讯作者：
BOMBARDIERI, RA
中科院分区：
文献类型：
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作者：
ROCHAMIRANDA, CE;LINDEN, R;BOMBARDIERI, RA
根据它们的触发特征，将固定负鼠（Didelphis marsupialis aurita）纹状皮层记录的127个单位中的98个，在强制呼吸一氧化二氮/二氧混合物的条件下，分为5个感受野组。第1组单位（20/27），响应于小的静止点，由响应类型相反且相互拮抗的区域组成，以线性边界分隔。激发最佳放电的刺激配置是由在视野中定位和定向的相反对比的直线区域组成的，这样既不会引起拮抗，又能最大限度地增加与响应该对比的区域的重叠。对于运动中的边缘，这些单元由亮放电中心和暗放电中心组成，它们的位置无法从地图上预测到静止点。除了位置和方向外，方向是另一个重要的刺激参数。组2单元（34/127）在整个感受野中对刺激定向、运动方向或两者都有统一的要求。宽度很少是一个显著的变量。检测到定向选择性、定向选择性和定向-方向敏感三个亚组。第3组（18/127）需要停止刺激。在大多数情况下（14/18），这种特性归因于具有相对非特异性刺激要求的抑制性环绕。观察定向和非定向反应感受野。没有环绕的第3组单元（4/18）对正确定位和定向的楔形响应最好，通常为90度。第4组（24/127）具有均匀的视场，刺激特异性较低，经常对漫射光有反应。虽然对刺激的方向和方向不敏感，但运动经常是最佳反应的必要条件。第5组感受野（2/127）有不同的反应类型区域集中排列，表现为相互拮抗。没有检测到对方位或方向的敏感性。29个单位仍未保密。其他组间的区别是，与组2相比，第4组单元的自发活性相对较高，第1组和第4组的场面积较大。根据它们的性质和感受野类型分布，负鼠的纹状感受野显然与其他哺乳动物的组织相似。
On the basis of their trigger-features, 98 of 127 units recorded in the striate cortex of immobilized opossums [Didelphis marsupialis aurita], under forced breathing of a nitrous oxide/O2 mixture, were classified into 5 receptive field groups. Group 1 units (20/27), responding to small stationary spots, made up of regions of opposite response type and mutual antagonism, separated by linear boundaries. The optimal discharge was elicited by a stimulus configuration consisting of rectilinear regions of opposite contrast positioned and oriented in the visual field so as not to elicit antagonism while maximizing the overlap with regions responsive to that contrast. To edges in motion these units were made up of light and dark discharge centers, the locations of which could not be predicted from the map to stationary spots. In addition to position and orientation, direction was another important stimulus parameter. Group 2 units (34/127) had uniform requirements of stimulus orientation, direction of motion or both, throughout the receptive field. Width was rarely a significant variable. Three subgroups were detected: orientation selective, directional selective and orientation-direction sensitive. Group 3 units (18/127) required stopped stimuli. In most instances (14/18) this property was attributed to a suppressive surround with relatively non-specific stimulus requirements. Oriented and non-oriented responsive receptive fields were observed. Group 3 units with no surround (4/18) responded best to properly positioned and oriented wedges, usually of 90.degree.. Group 4 units (24/127) had uniform fields with little stimulus specificity and were often responsive to diffuse light. Although not sensitive to stimulus orientation and direction, motion was frequently a requisite for optimal responses. Group 5 receptive fields (2/127) had concentrically arranged regions of distinct response type which displayed mutual antagonism. No sensitivity to orientation or direction was detected. Twenty-nine units remained unclassified. Other group distinctions were the relatively higher spontaneous activity of group 4 units and the large field sizes encountered among groups 1 and 4 when compared to group 2. Based on their properties and receptive field type distribution, striate receptive fields in the opossum apparently have a similar organization to those of other mammals.