Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
Science. 2012 Jun 15;336(6087):1458-61. doi: 10.1126/science.1222017.
In central neurons, information flows from the dendritic surface toward the axon terminals. We found that during in vitro gamma oscillations, ectopic action potentials are generated at high frequency in the distal axon of pyramidal cells (PCs) but do not invade the soma. At the same time, axo-axonic cells (AACs) discharged at a high rate and tonically inhibited the axon initial segment, which can be instrumental in preventing ectopic action potential back-propagation. We found that activation of a single AAC substantially lowered soma invasion by antidromic action potential in postsynaptic PCs. In contrast, activation of soma-inhibiting basket cells had no significant impact. These results demonstrate that AACs can separate axonal from somatic activity and maintain the functional polarization of cortical PCs during network oscillations.
在中枢神经元中，信息从树突表面流向轴突末梢。我们发现，在体外γ振荡期间，树突状细胞（PC）的远端轴突中以高频产生异位动作电位，但不会侵入胞体。与此同时，轴突-轴突细胞（AAC）以高频率放电并持续抑制轴突起始段，这有助于防止异位动作电位逆行传播。我们发现，单个 AAC 的激活可显著降低突触后 PC 中逆行动作电位引起的胞体入侵。相比之下，激活抑制胞体的篮状细胞没有显著影响。这些结果表明，AAC 可以将轴突活动与胞体活动分开，并在网络振荡过程中维持皮质 PC 的功能极化。
