Although dopamine is known to promote wakefulness, the specific dopamine circuits in the brain that regulate arousal are not clear. Here Taylor et al. report that selective optogenetic stimulation of ventral tegmental area (VTA) dopamine neurons in mice produces a powerful arousal response sufficient to restore conscious behaviors, including the righting reflex, during continuous, steady-state general anesthesia. Although previous studies found that VTA dopamine neurons do not appear to play a central role in regulating sleep–wake transitions, these results demonstrate that selective stimulation of these neurons is sufficient to induce the transition from an unconscious, anesthetized state to an awake state. The authors concluded that VTA dopamine neurons play a critical role in promoting wakefulness.
Taylor NE, Van Dort CJ, Kenny JD, Pei JZ, Guidera JA, Vlasov KY, Lee JT, Boyden ES, Brown EN, and Solt K: Optogenetic activation of dopamine neurons in the ventral tegmental area induces reanimation from general anesthesia. Proc. Natl. Acad. Sci. USA [Epub ahead of print October 24, 2016; doi:10.1073/pnas.1614340113].