Institute of Neuroscience, Technical University Munich, Biedersteiner Strasse 29, 80802 Munich, Germany.
Neuron. 2013 Mar 20;77(6):1136-50. doi: 10.1016/j.neuron.2013.01.031.
Corticothalamic slow oscillations of neuronal activity determine internal brain states. At least in the cortex, the electrical activity is associated with large neuronal Ca(2+) transients. Here we implemented an optogenetic approach to explore causal features of the generation of slow oscillation-associated Ca(2+) waves in the in vivo mouse brain. We demonstrate that brief optogenetic stimulation (3-20 ms) of a local group of layer 5 cortical neurons is sufficient for the induction of global brain Ca(2+) waves. These Ca(2+) waves are evoked in an all-or-none manner, exhibit refractoriness during repetitive stimulation, and propagate over long distances. By local optogenetic stimulation, we demonstrate that evoked Ca(2+) waves initially invade the cortex, followed by a secondary recruitment of the thalamus. Together, our results establish that synchronous activity in a small cluster of layer 5 cortical neurons can initiate a global neuronal wave of activity suited for long-range corticothalamic integration.
皮质丘脑慢波活动决定了大脑的内部状态。至少在大脑皮层中，电活动与大神经元 Ca(2+)瞬变有关。在这里，我们采用光遗传学方法来探索在活体小鼠大脑中与慢振荡相关的 Ca(2+)波产生的因果特征。我们证明，对局部一群 5 层皮质神经元进行短暂的光遗传学刺激（3-20 毫秒）足以诱导全脑 Ca(2+)波。这些 Ca(2+)波以全或无的方式被激发，在重复刺激期间表现出不应期，并能长距离传播。通过局部光遗传学刺激，我们证明，诱发的 Ca(2+)波最初侵入皮层，随后丘脑被募集。总之，我们的结果表明，一小群 5 层皮质神经元的同步活动可以引发适合长距离皮质丘脑整合的全脑神经元活动波。
