title: A Neural Circuit That Controls Cortical State, Plasticity, and the Gain of Sensory Responses in Mouse.
abstract: Neurons in the visual cortex were first found to be exquisitely selective for particular properties of visual stimuli in anesthetized animals, including mice. Studies of alert mice in an apparatus that allowed them to stand or run revealed that locomotion causes a change in cortical state that dramatically increases the magnitude of responses in neurons of the visual cortex without altering selectivity, effectively changing the gain of sensory responses. Locomotion also dramatically enhances adult plasticity in the recovery from long-term visual deprivation. We have studied the elements and operation of the neural circuit responsible for the enhancement of activity and shown that it enhances plasticity even in mice not free to run. The circuit consists of projections ascending from the midbrain locomotor region (MLR) to the basal forebrain, activating cholinergic and perhaps other projections to excite inhibitory interneurons expressing vasoactive intestinal peptide (VIP) in the visual cortex. VIP cells activated by locomotion inhibit interneurons that express somatostatin (SST), thereby disinhibiting the excitatory principal neurons and allowing them to respond more strongly to effective visual stimuli. These findings reveal in alert animals how the ascending reticular activating system described in anesthetized animals 50 years ago operates to control cortical state.
authors.affiliation: Center for Integrative Neuroscience, Department of Physiology, University of California, San Francisco, California 94143-0444 stryker@phy.ucsf.edu.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Stryker
mesh_terms: D000818:Animals; D008124:Locomotion; D051379:Mice; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D012677:Sensation / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*