W. M. Keck Center for Neurophysics, Integrative Center for Learning and Memory, and Brain Research Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Neuroscience Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90095, USA.
Science. 2017 Mar 24;355(6331). doi: 10.1126/science.aaj1497. Epub 2017 Mar 9.
Neural activity in vivo is primarily measured using extracellular somatic spikes, which provide limited information about neural computation. Hence, it is necessary to record from neuronal dendrites, which can generate dendritic action potentials (DAPs) in vitro, which can profoundly influence neural computation and plasticity. We measured neocortical sub- and suprathreshold dendritic membrane potential (DMP) from putative distal-most dendrites using tetrodes in freely behaving rats over multiple days with a high degree of stability and submillisecond temporal resolution. DAP firing rates were several-fold larger than somatic rates. DAP rates were also modulated by subthreshold DMP fluctuations, which were far larger than DAP amplitude, indicating hybrid, analog-digital coding in the dendrites. Parietal DAP and DMP exhibited egocentric spatial maps comparable to pyramidal neurons. These results have important implications for neural coding and plasticity.
体内神经活动主要通过细胞外体峰来测量，但其提供的神经计算信息有限。因此，有必要从神经元树突进行记录，树突在体外可以产生树突动作电位（DAP），而这些 DAP 可以深刻影响神经计算和可塑性。我们使用四极管在自由活动的大鼠中，在多天内测量新皮层亚阈值和超阈值树突膜电位（DMP），具有高度稳定性和亚毫秒级的时间分辨率。DAP 的发射率比体细胞率高几个数量级。DAP 率也受到亚阈值 DMP 波动的调制，其波动幅度远大于 DAP 幅度，表明在树突中存在混合的、模拟-数字编码。顶叶 DAP 和 DMP 表现出与锥体神经元相当的自我中心空间图谱。这些结果对神经编码和可塑性具有重要意义。
