Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Edmond and Lily Safra Center for Brain Sciences and Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
Cell Rep. 2018 Apr 24;23(4):1034-1044. doi: 10.1016/j.celrep.2018.03.103.
The excitability of the apical tuft of layer 5 pyramidal neurons is thought to play a crucial role in behavioral performance and synaptic plasticity. We show that the excitability of the apical tuft is sensitive to adrenergic neuromodulation. Using two-photon dendritic Ca imaging and in vivo whole-cell and extracellular recordings in awake mice, we show that application of the α2A-adrenoceptor agonist guanfacine increases the probability of dendritic Ca events in the tuft and lowers the threshold for dendritic Ca spikes. We further show that these effects are likely to be mediated by the dendritic current I. Modulation of I in a realistic compartmental model controlled both the generation and magnitude of dendritic calcium spikes in the apical tuft. These findings suggest that adrenergic neuromodulation may affect cognitive processes such as sensory integration, attention, and working memory by regulating the sensitivity of layer 5 pyramidal neurons to top-down inputs.
树突顶帽层 5 锥体神经元的兴奋性被认为在行为表现和突触可塑性中起着关键作用。我们表明，顶帽的兴奋性对肾上腺素能神经调制敏感。我们使用双光子树突钙成像和清醒小鼠的体内全细胞和细胞外记录，表明应用α2A-肾上腺素受体激动剂胍法辛增加了树突钙事件在顶帽中的概率，并降低了树突钙峰的阈值。我们进一步表明，这些作用可能是由树突电流 I 介导的。在一个现实的分区模型中，调制 I 控制了树突顶帽中树突钙峰的产生和幅度。这些发现表明，通过调节 5 层锥体神经元对自上而下输入的敏感性，肾上腺素能神经调制可能会影响感觉整合、注意力和工作记忆等认知过程。
