title: Making waves: initiation and propagation of corticothalamic Ca2+ waves in vivo.
abstract: 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.
authors.affiliation: Institute of Neuroscience, Technical University Munich, Biedersteiner Strasse 29, 80802 Munich, Germany.
authors.forename: Albrecht
authors.initials: A
authors.lastname: Stroh
authors.forename: Helmuth
authors.initials: H
authors.lastname: Adelsberger
authors.forename: Alexander
authors.initials: A
authors.lastname: Groh
authors.forename: Charlotta
authors.initials: C
authors.lastname: Rühlmann
authors.forename: Sebastian
authors.initials: S
authors.lastname: Fischer
authors.forename: Anja
authors.initials: A
authors.lastname: Schierloh
authors.forename: Karl
authors.initials: K
authors.lastname: Deisseroth
authors.forename: Arthur
authors.initials: A
authors.lastname: Konnerth
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000502:physiology; D062308:Optogenetics / Q000379:methods; D010775:Photic Stimulation / Q000379:methods; D013788:Thalamus / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*