Making waves: initiation and propagation of corticothalamic Ca2+ waves in vivo

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium Signaling / physiology*
  • Cerebral Cortex / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Neural Pathways / physiology
  • Optogenetics / methods
  • Photic Stimulation / methods
  • Thalamus / physiology*
  • Visual Cortex / physiology*