Spatiotemporal properties of layer V neurons of the rat primary somatosensory cortex
Spatiotemporal properties of layer V neurons of the rat primary somatosensory cortex
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DOI：
10.1093/cercor/9.4.348
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发表时间：
1999-06-01
期刊：
影响因子：
3.7
通讯作者：
Nicolelis, MAL
中科院分区：
文献类型：
--
作者：
Ghazanfar, AA;Nicolelis, MAL
动物在自然环境中主动处理时空复杂的感觉信号，以指导适应性行为。因此，单个神经元和神经系统的特性似乎都反映了这种相互作用的动态特性。在探索行为中，老鼠移动它们的胡须来主动区分不同的触觉特征。我们研究了这种动态感觉处理是否反映在大鼠初级体感觉皮层“须区”第五层神经元的时空特性上。我们发现，大多数V层神经元具有较大的时空感受野（8.5 +/- 4.9须）（即单个细胞对不同须的响应是刺激后时间的函数），并且周围须的兴奋反应形成了一个空间兴奋梯度，这似乎反映了在自然行为中腹侧和尾侧须的更多使用。对V层神经元集合的分析表明，单须刺激激活了V层的一部分，远远超出了单个皮质柱（平均5.6个皮质柱）。基于这些结果，我们得出结论，大鼠初级体感皮层似乎不是作为触觉信息的静态解码器来运作的。相反，我们的数据表明，大鼠的触觉处理可能涉及丘脑皮质通路中广泛调谐的神经元群体之间的持续相互作用。
Animals in their natural environments actively process spatiotemporally complex sensory signals in order to guide adaptive behavior. It therefore seems likely that the properties of both single neurons and neural ensembles should reflect the dynamic nature of such interactions. During exploratory behaviors, rats move their whiskers to actively discriminate between different tactile features. We investigated whether this dynamic sensory processing was reflected in the spatial and temporal properties of neurons in layer V of the 'whisker area' in the rat primary somatosensory cortex. We found that the majority of layer V neurons had large (8.5 +/- 4.9 whiskers) spatiotemporal receptive fields (i.e. individual cells responded best to different whiskers as a function of post-stimulus time), and that the excitatory responses of surround whiskers formed a spatial gradient of excitation that seemed to reflect the greater use of the ventral and caudal whiskers during natural behaviors. Analyses of ensembles of layer V neurons revealed that single whisker stimuli activated a portion of layer V that extends well beyond a single cortical column (average of 5.6 barrel cortical columns). Based on these results, we conclude that the rat primary somatosensory cortex does not appear to operate as a static decoder of tactile information. On the contrary, our data suggest that tactile processing in rats is likely to involve the on-going interactions between populations of broadly tuned neurons in the thalamocortical pathway.