Modeling population responses of rapidly-adapting mechanoreceptive fibers
Modeling population responses of rapidly-adapting mechanoreceptive fibers
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DOI：
10.1023/a:1016535413000
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发表时间：
2002-05-01
影响因子：
1.2
通讯作者：
Bolanowski, SJ
中科院分区：
文献类型：
--
作者：
Güçlü, B;Bolanowski, SJ
快速适应(RA)纤维的群体反应是触觉生理底物的一个组成部分。在此，我们描述了一种基于K.O.Johnson(J.NeuroPhysiol.37：48-72,1974)，我们通过允许包括连接到RA纤维的无毛皮肤中受体的空间分布的能力来扩展。所模拟的假设情况为矩形、均匀随机和近端-远端高斯分布。每个空间组织产生的定性不同的人口反应概况也因刺激参数的不同而不同。研究了刺激幅度、平均神经支配密度和接触器-探头位置等不同的反应指标对刺激幅度、平均神经支配密度和接触器-探头位置的影响。测量结果在模拟的解剖分布之间进行了统计比较。对于矩形分布和均匀随机分布，响应是相同的，它们都具有均匀的神经密度。然而，当测量没有在代表更高阶神经元感受野的子集总体上平均时，高斯分布产生了统计上不同的反应。这些结果表明，除了刺激参数外，解剖组织也是群体反应的重要决定因素。因此，重建群体活动以检验心理物理假说目前必须小心进行，直到皮肤内受体的组织被弄清楚为止。
The population response of rapidly-adapting (RA) fibers is one component of the physiological substrate of the sense of touch. Herein, we describe a computational scheme based on the population-response model by K.O. Johnson (J. Neurophysiol. 37: 48-72, 1974) which we extended by permitting the capability to include the spatial distributions of receptors in the glabrous skin linked to RA fibers. The hypothetical cases simulated were rectangular, uniformly random and proximo-distally Gaussian distributions. Each spatial organization produced qualitatively distinct population-response profiles that also varied due to stimulus parameters. The effects of stimulus amplitude, average innervation density and contactor-probe location were studied by considering various response measures: number of active fibers, summated firing rate and the average firing rate of a subset of the modeled population. The outcome of the measures were statistically compared among simulated anatomical distributions. The response is the same for rectangular and uniformly random distributions, both of which have a homogeneous innervation density. However, the Gaussian distribution produced statistically different responses when the measure was not averaged over the subset population which represented the receptive field of a higher-order neuron. These results indicate that, as well as stimulus parameters, the anatomical organization is a significant determinant of the population response. Therefore, reconstructing population activity for testing psychophysical hypotheses must presently be done with care until the organization of the receptors within the skin has been clarified.