Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
Neuron. 2021 Mar 3;109(5):778-787.e3. doi: 10.1016/j.neuron.2020.12.018. Epub 2021 Jan 19.
Fast synaptic transmission relies upon the activation of ionotropic receptors by neurotransmitter release to evoke postsynaptic potentials. Glutamate and GABA play dominant roles in driving highly dynamic activity in synaptically connected neuronal circuits, but ionotropic receptors for other neurotransmitters are also expressed in the neocortex, including nicotinic receptors, which are non-selective cation channels gated by acetylcholine. To study the function of non-glutamatergic excitation in neocortex, we used two-photon microscopy to target whole-cell membrane potential recordings to different types of genetically defined neurons in layer 2/3 of primary somatosensory barrel cortex in awake head-restrained mice combined with pharmacological and optogenetic manipulations. Here, we report a prominent nicotinic input, which selectively depolarizes a subtype of GABAergic neuron expressing vasoactive intestinal peptide leading to disinhibition during active sensorimotor processing. Nicotinic disinhibition of somatosensory cortex during active sensing might contribute importantly to integration of top-down and motor-related signals necessary for tactile perception and learning.
快速的突触传递依赖于神经递质释放激活离子型受体，从而引发突触后电位。谷氨酸和 GABA 在驱动突触连接神经元回路中高度动态的活动方面发挥主导作用，但其他神经递质的离子型受体也在新皮层中表达，包括烟碱型受体，它是由乙酰胆碱门控的非选择性阳离子通道。为了研究非谷氨酸能兴奋在新皮层中的功能，我们使用双光子显微镜将全细胞膜电位记录靶向到清醒束缚头部小鼠初级体感皮层 2/3 层中不同类型的基因定义神经元，并结合药理学和光遗传学操作。在这里，我们报告了一个显著的烟碱输入，它选择性地去极化表达血管活性肠肽的 GABA 能神经元亚型，在主动感觉运动处理过程中导致去抑制。在主动感觉过程中，体感皮层的烟碱去抑制可能对整合用于触觉感知和学习的自上而下和与运动相关的信号非常重要。
