Synaptic Mechanisms Underlying Sparse Coding of Active Touch
Synaptic Mechanisms Underlying Sparse Coding of Active Touch
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DOI：
10.1016/j.neuron.2011.02.022
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发表时间：
2011-03-24
期刊：
影响因子：
16.2
通讯作者：
Petersen, Carl C. H.
中科院分区：
文献类型：
--
作者：
Crochet, Sylvain;Poulet, James F. A.;Petersen, Carl C. H.
动物主动收集感觉信息，但在主动感觉处理过程中驱动神经元回路功能的突触机制知之甚少。在这里，我们研究了突触驱动的膜电位动态活动胡须感觉使用全细胞记录从第2/3层锥体神经元在初级躯体感觉桶皮层的行为小鼠。虽然胡须与物体的接触在所有神经元中引起快速去极化，但这些触摸反应仅在近似10%的细胞中驱动动作电位。这种稀疏编码是由触摸诱发反应的细胞特异性反转电位确保的，这些反转电位相对于大多数神经元的动作电位阈值是超极化的。交互间隔深刻地影响触摸诱发的突触后电位，有趣的是不影响触摸反应的峰值膜电位。双全细胞记录表明在主动触摸过程中高度相关的膜电位动态。因此，同步皮质层2/3微电路内的稀疏动作电位放电似乎稳健地发信号通知每个主动触摸响应。
Sensory information is actively gathered by animals, but the synaptic mechanisms driving neuronal circuit function during active sensory processing are poorly understood. Here, we investigated the synaptically driven membrane potential dynamics during active whisker sensation using whole-cell recordings from layer 2/3 pyramidal neurons in the primary somatosensory barrel cortex of behaving mice. Although whisker contact with an object evoked rapid depolarization in all neurons, these touch responses only drove action potentials in similar to 10% of the cells. Such sparse coding was ensured by cell-specific reversal potentials of the touch-evoked response that were hyperpolarized relative to action potential threshold for most neurons. Intercontact interval profoundly influenced touch-evoked postsynaptic potentials, interestingly without affecting the peak membrane potential of the touch response. Dual whole-cell recordings indicated highly correlated membrane potential dynamics during active touch. Sparse action potential firing within synchronized cortical layer 2/3 microcircuits therefore appears to robustly signal each active touch response.