Simulation of motion on the skin. II. Cutaneous mechanoreceptor coding of the width and texture of bar patterns displaced across the OPTACON.
Simulation of motion on the skin. II. Cutaneous mechanoreceptor coding of the width and texture of bar patterns displaced across the OPTACON.
复制标题
模拟皮肤上的运动。
DOI：
10.1152/jn.1989.62.6.1437
复制
发表时间：
1989
影响因子：
2.5
通讯作者：
Palmer,CI
中科院分区：
文献类型：
--
作者：
Gardner,EP;Palmer,CI
1.本实验考察了感受野结构对信息加工的功能意义。以往的研究表明，快速适应(RA)传入神经元可以汇聚14-25个触觉小体的信息，而支配太平洋小体(PC)的传入神经元只有一个大的感受器终末。我们检验了两种截然相反的功能结构假说：1)总和模型，在该模型中，传入神经元整合了来自其所有终末的信号，显示出活动随接触面积的单调增加；2)赢家通吃模型，在该模型中，簇中最强激活的受体通过抵消来自其他分支的信号来控制轴突输出。2.使用计算机控制的顺序激活的微型探头栅格(OPTACON刺激器)，以30-120 mm的速度扫过猴子的手指或手掌上的条形和条纹图案/S。OPTACON探测器的密集排列允许在单个感受野中放置最多五组刺激器，使我们能够同时激活一个或多个触觉小体簇，并通过皮肤刺激不同方向的PC传入小体。来自移动条形图案的信息集成已经用两种协议进行了测试。在可变宽度方案中，图案中被激活的行的总数从1变化到5，脉冲行之间的恒定间隔为1.2 mm。在可变密度方案中，刺激皮肤的长度保持在5 mm不变，刺激间隔变化。3.RA传入神经元在其感受野中没有显示出输入的总和。宽横杆在场上的运动增加了射击的持续时间，但不会增加每个脉冲诱发的总尖峰。对宽条前沿的反应被发现与单行条的反应是相同的。同时激活两到五行与单独测试最有效的单独行相比，每个脉冲产生相同或更少的尖峰。当宽条模式集中在场上，接触最大数量的受体时，RAS跟随主要分支或终末的活动，抑制额外的输入。在所测试的所有脉冲频率(25-100赫兹)上观察到缺少求和。4.只要至少有一行刺激感受野，移动的条形图案就会引起反应；较宽的条形图案会引起更长的棘波，其脉冲总数与条形宽度成正比。
1. These experiments assay the functional significance of receptive-field architecture for information processing. Rapidly adapting (RA) afferents have been previously shown to converge information from clusters of 14-25 Meissner's corpuscles, whereas afferents innervating Pacinian corpuscles (PCs) have only a single, large receptor terminal. We tested two opposing hypotheses of functional architecture: 1) summation models, in which an afferent integrates signals from all of its terminals, showing monotonic increases in activity as a function of contact area, and 2) winner-take-all models, in which the most strongly activated receptor in the cluster dominates axonal output by cancellation of signals from other branches. 2. Bar and stripe patterns have been swept across the finger or palm of the monkey's hand at speeds of 30-120 mm/s with the use of a computer-controlled grid of sequentially activated miniature probes (OPTACON stimulator). The dense packing of OPTACON probes permits placement of up to five groups of stimulators within an individual receptive field, allowing us to activate one or more clusters of Meissner's corpuscles simultaneously and to stimulate the bulbar corpuscle of PC afferents at different orientations through the skin. Integration of information from moving bar patterns has been tested with two protocols. In the variable width protocol, the total number of activated rows in the pattern is varied from one to five, with a constant spacing of 1.2 mm between pulsed rows. In the variable density protocol, the length of skin stimulated is held constant at 5 mm and the spacing of stimuli varied. 3. RA afferents show no evidence of summation of inputs within their receptive fields. Motion of wide bars across the field increases the duration of firing but not the total spikes evoked by each pulse. Responses to the leading edge of wide bars were found to be identical to those evoked by a single-row bar. Simultaneous activation of two to five rows evokes the same or fewer spikes per pulse than the most effective individual row tested alone. When broad-bar patterns are centered over the field, contacting the maximum number of receptors, RAs follow activity in the dominant branch or terminus, suppressing additional inputs. Lack of summation is observed at all pulse frequencies tested (25-100 Hz). 4. Moving bar patterns evoke responses as long as at least one row stimulates the receptive field; broader patterns evoke longer spike trains whose total number of impulses is proportional to bar width.(ABSTRACT TRUNCATED AT 400 WORDS)