Invariant computations in local cortical networks with balanced excitation and inhibition
Invariant computations in local cortical networks with balanced excitation and inhibition
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DOI：
10.1038/nn1391
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发表时间：
2005-02-01
影响因子：
25
通讯作者：
Sur, M
中科院分区：
文献类型：
--
作者：
Mariño, J;Schummers, J;Sur, M
皮质计算关键涉及局部神经元回路。计算通常在皮层区域是不变的，但由网络执行，根据其功能结构，该区域内的网络可能会有很大变化。在这里，我们展示了一种机制，通过这种机制，在猫的初级视觉皮层的方向偏好图，提供了广泛的多样性的本地电路不变的计算方向选择性。视觉诱发的兴奋性和抑制性突触电导在皮层神经元中平衡得很好，因此在所有地图位置都保持了尖峰响应的急剧调整。这种功能平衡来自兴奋性和抑制性细胞的空间各向同性局部连接。建模结果表明，这种协变是经常性的，而不是纯粹的前馈处理的签名，所观察到的各向同性的本地电路是足以产生不变的尖峰调谐。
Cortical computations critically involve local neuronal circuits. The computations are often invariant across a cortical area yet are carried out by networks that can vary widely within an area according to its functional architecture. Here we demonstrate a mechanism by which orientation selectivity is computed invariantly in cat primary visual cortex across an orientation preference map that provides a wide diversity of local circuits. Visually evoked excitatory and inhibitory synaptic conductances are balanced exquisitely in cortical neurons and thus keep the spike response sharply tuned at all map locations. This functional balance derives from spatially isotropic local connectivity of both excitatory and inhibitory cells. Modeling results demonstrate that such covariation is a signature of recurrent rather than purely feed-forward processing and that the observed isotropic local circuit is sufficient to generate invariant spike tuning.