Institute of Physiology I, Universität Freiburg, Engesserstrasse 4, D-79108 Freiburg, Germany.
Science. 2010 Jan 1;327(5961):52-8. doi: 10.1126/science.1177876. Epub 2009 Dec 3.
Fast-spiking, parvalbumin-expressing basket cells (BCs) are important for feedforward and feedback inhibition. During network activity, BCs respond with short latency and high temporal precision. It is thought that the specific properties of input synapses are responsible for rapid recruitment. However, a potential contribution of active dendritic conductances has not been addressed. We combined confocal imaging and patch-clamp techniques to obtain simultaneous somatodendritic recordings from BCs. Action potentials were initiated in the BC axon and backpropagated into the dendrites with reduced amplitude and little activity dependence. These properties were explained by a high K+ to Na+ conductance ratio in BC dendrites. Computational analysis indicated that dendritic K+ channels convey unique integration properties to BCs, leading to the rapid and temporally precise activation by excitatory inputs.
快速放电、表达钙结合蛋白 Parvalbumin 的篮状细胞 (BCs) 对于前馈和反馈抑制很重要。在网络活动期间，BC 以短潜伏期和高时间精度做出响应。人们认为输入突触的特定特性负责快速招募。然而，活跃树突电导的潜在贡献尚未得到解决。我们结合共聚焦成像和膜片钳技术从 BC 获得同时的体树突记录。动作电位在 BC 轴突中发起，并以降低的幅度和几乎没有活动依赖性逆行传播到树突中。这些特性可以用 BC 树突中的高 K+ 到 Na+ 电导比来解释。计算分析表明，树突 K+ 通道为 BC 提供独特的整合特性，导致兴奋性输入的快速和时间精确激活。
