Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Neuron. 2010 Feb 11;65(3):422-35. doi: 10.1016/j.neuron.2010.01.006.
Computations in cortical circuits are mediated by synaptic interactions between excitatory and inhibitory neurons, and yet we know little about their activity in awake animals. Here, through single and dual whole-cell recordings combined with two-photon microscopy in the barrel cortex of behaving mice, we directly compare the synaptically driven membrane potential dynamics of inhibitory and excitatory layer 2/3 neurons. We find that inhibitory neurons depolarize synchronously with excitatory neurons, but they are much more active with differential contributions of two classes of inhibitory neurons during different brain states. Fast-spiking GABAergic neurons dominate during quiet wakefulness, but during active wakefulness Non-fast-spiking GABAergic neurons depolarize, firing action potentials at increased rates. Sparse uncorrelated action potential firing in excitatory neurons is driven by fast, large, and cell-specific depolarization. In contrast, inhibitory neurons fire correlated action potentials at much higher frequencies driven by slower, smaller, and broadly synchronized depolarization.
皮层回路中的计算是由兴奋性和抑制性神经元之间的突触相互作用介导的，但我们对清醒动物中它们的活动知之甚少。在这里，通过在行为小鼠的桶状皮层中进行的单和双全细胞记录以及双光子显微镜，我们直接比较了兴奋性和抑制性 2/3 层神经元的突触驱动膜电位动力学。我们发现抑制性神经元与兴奋性神经元同步去极化，但它们在不同的脑状态下具有不同的两类抑制性神经元的差异贡献，表现出更高的活性。快速放电 GABA 能神经元在安静觉醒时占主导地位，但在活跃觉醒时，非快速放电 GABA 能神经元去极化，以增加的频率发射动作电位。兴奋性神经元中稀疏的不相关动作电位发射是由快速、大且细胞特异性的去极化驱动的。相比之下，抑制性神经元以较慢、较小且广泛同步的去极化驱动的更高频率发射相关动作电位。
