Functional independence of layer IV barrels in rodent somatosensory cortex
Functional independence of layer IV barrels in rodent somatosensory cortex
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DOI：
10.1152/jn.1999.82.3.1311
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发表时间：
1999-09-01
影响因子：
2.5
通讯作者：
Simons, DJ
中科院分区：
文献类型：
--
作者：
Goldreich, D;Kyriazi, HT;Simons, DJ
啮齿动物初级体感皮层的第TV层以一组与须相关的神经元群为特征，这些神经元群被称为“桶”。每个桶内的神经元对对侧面部的特定须反应最好，当相邻须偏转时，表现出相对较弱的兴奋，然后是强烈的抑制。对于第四层中振动信息的处理，一个重要的假设是桶状神经元的多须接受野反映了相邻桶状神经元之间的相互联系。另一种观点认为，桶状神经元的接受野特性来自于每个桶内的局部电路对多晶须和丘脑输入进行的操作，独立于邻近的桶。在这里，我们报告了相邻晶须诱发的激发和抑制在一个桶内不受相应相邻桶的消融影响。另一方面，在核上神经元中，对被切除的脑桶相关须的兴奋性反应大大减少。我们得出结论，第四层桶的功能是一组独立的并行处理器，每个处理器单独转换丘脑传入输入，以便通过其他层中水平连接的电路进行后续处理。
Layer TV of rodent primary somatosensory cortex is characterized by an array of whisker-related groups of neurons, known as "barrels." Neurons within each barrel respond best to a particular whisker on the contralateral face, and, on deflection of adjacent whiskers, display relatively weak excitation followed by strong inhibition. A prominent hypothesis for the processing of vibrissal information within layer IV is that the multiwhisker receptive fields of barrel neurons reflect interconnections among neighboring barrels. An alternative view is that the receptive field properties of barrel neurons are derived from operations performed on multiwhisker, thalamic inputs by local circuitry within each barrel, independently of neighboring barrels. Here we report that adjacent whisker-evoked excitation and inhibition within a barrel are unaffected by ablation of the corresponding adjacent barrel. In supragranular neurons, on the other hand, excitatory responses to the ablated barrel's associated whisker are substantially reduced. We conclude that the layer IV barrels function as an array of independent parallel processors, each of which individually transforms thalamic afferent input for subsequent processing by horizontally interconnected circuits in other layers.