title: Cortico-fugal output from visual cortex promotes plasticity of innate motor behaviour.
abstract: The mammalian visual cortex massively innervates the brainstem, a phylogenetically older structure, via cortico-fugal axonal projections. Many cortico-fugal projections target brainstem nuclei that mediate innate motor behaviours, but the function of these projections remains poorly understood. A prime example of such behaviours is the optokinetic reflex (OKR), an innate eye movement mediated by the brainstem accessory optic system, that stabilizes images on the retina as the animal moves through the environment and is thus crucial for vision. The OKR is plastic, allowing the amplitude of this reflex to be adaptively adjusted relative to other oculomotor reflexes and thereby ensuring image stability throughout life. Although the plasticity of the OKR is thought to involve subcortical structures such as the cerebellum and vestibular nuclei, cortical lesions have suggested that the visual cortex might also be involved. Here we show that projections from the mouse visual cortex to the accessory optic system promote the adaptive plasticity of the OKR. OKR potentiation, a compensatory plastic increase in the amplitude of the OKR in response to vestibular impairment, is diminished by silencing visual cortex. Furthermore, targeted ablation of a sparse population of cortico-fugal neurons that specifically project to the accessory optic system severely impairs OKR potentiation. Finally, OKR potentiation results from an enhanced drive exerted by the visual cortex onto the accessory optic system. Thus, cortico-fugal projections to the brainstem enable the visual cortex, an area that has been principally studied for its sensory processing function, to plastically adapt the execution of innate motor behaviours.
authors.affiliation: Howard Hughes Medical Institute and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, California 92093-0634, USA.|Neurobiology Section and Department of Neuroscience, University of California San Diego, La Jolla, California 92093-0634, USA.
authors.forename: Bao-Hua
authors.initials: BH
authors.lastname: Liu
authors.affiliation: Department of Neurobiology, Stanford University School of Medicine, Palo Alto, California 94305, USA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Huberman
authors.affiliation: Howard Hughes Medical Institute and Center for Neural Circuits and Behavior, University of California San Diego, La Jolla, California 92093-0634, USA.|Neurobiology Section and Department of Neuroscience, University of California San Diego, La Jolla, California 92093-0634, USA.|Department of Physiology, University of California San Francisco, San Francisco, California 94143-0444, USA.
authors.forename: Massimo
authors.initials: M
authors.lastname: Scanziani
mesh_terms: D000818:Animals; D001933:Brain Stem / Q000502:physiology*; D002531:Cerebellum / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008813:Mice, Inbred ICR; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D012018:Reflex / Q000502:physiology*; D012160:Retina / Q000502:physiology; D014726:Vestibular Nuclei / Q000502:physiology; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*