Origins of Cortical Layer V Surround Receptive Fields in the Rat Barrel Cortex
Origins of Cortical Layer V Surround Receptive Fields in the Rat Barrel Cortex
复制标题
DOI：
10.1152/jn.00560.2009
复制
发表时间：
2010-02-01
影响因子：
2.5
通讯作者：
Fox, Kevin
中科院分区：
文献类型：
--
作者：
Wright, Nicholas;Fox, Kevin
Wright N，Fox K。皮质层 V 的起源围绕大鼠桶状皮层的感受野。 J Neurophysiol 103: 709-724, 2010。首次发表于 2009 年 11 月 25 日； doi：10.1152/jn.00560.2009。桶状皮层的第四层包含对侧胡须垫的解剖图，它可以作为将细胞的感受野特性与其所在的皮层柱联系起来的有用参考。最近的研究表明，第四层细胞的周围感受野在皮质内或皮质下产生的程度取决于它们是位于桶状还是间隔柱中。为了研究V层细胞是否如此，我们通过从皮质表面注入蝇蕈醇并在局部离子电渗荷包牡丹碱存在的情况下测量对感觉刺激的尖峰反应来阻断桶状皮层的皮质内活动。桶下方的第五层细胞具有较小的皮质下生成的单或双晶须中心感受野和较大的皮质内生成的六至七个晶须周围感受野。相反，位于隔膜的细胞接收来自皮层下和皮层来源的多须输入。 Va 层和 Vb 层细胞的大多数特性非常相似。然而，与 Va 层细胞相比，Vb 层桶状神经元表现出相对缺乏由感觉输入引起的阶段性抑制。在没有来自浅层的输入的情况下，对 V 层细胞的直接丘脑输入不足以引起感觉反应。这些发现表明，尽管第五层感受野明显相似，但桶状皮层和隔膜细分在桶状皮层内处理不同来源的信息。
Wright N, Fox K. Origins of cortical layer V surround receptive fields in the rat barrel cortex. J Neurophysiol 103: 709-724, 2010. First published November 25, 2009; doi: 10.1152/jn.00560.2009. Layer IV of the barrel cortex contains an anatomical map of the contralateral whisker pad, which serves as a useful reference in relating receptive field properties of cells to the cortical columns in which they reside. Recent studies have shown that the degree to which the surround receptive fields of layer IV cells are generated intracortically or subcortically depends on whether they lie in barrel or septal columns. To investigate whether this is true for layer V cells, we blocked intracortical activity in the barrel cortex by infusing muscimol from the cortical surface and measuring spike responses to sensory stimulation in the presence of locally iontophoresed bicuculline. Layer V cells beneath barrels had small subcortically generated single- or double-whisker center receptive fields and larger intracortically generated six to seven whisker surround receptive fields. Conversely, septally located cells received multiwhisker input from both subcortical and cortical sources. Most properties of layer Va and layer Vb cells were very similar. However, layer Vb barrel neurons showed a relative lack of phasic inhibition evoked from sensory input compared with layer Va cells. The direct thalamic input to the layer V cells was not sufficient to evoke a sensory response in the absence of input from superficial layers. These findings suggest that despite the apparent overt similarity of layer V receptive fields, barrel and septal subdivisions process different sources of information within the barrel cortex.