title: Rapid recovery from the effects of early monocular deprivation is enabled by temporary inactivation of the retinas.
abstract: A half-century of research on the consequences of monocular deprivation (MD) in animals has revealed a great deal about the pathophysiology of amblyopia. MD initiates synaptic changes in the visual cortex that reduce acuity and binocular vision by causing neurons to lose responsiveness to the deprived eye. However, much less is known about how deprivation-induced synaptic modifications can be reversed to restore normal visual function. One theoretically motivated hypothesis is that a period of inactivity can reduce the threshold for synaptic potentiation such that subsequent visual experience promotes synaptic strengthening and increased responsiveness in the visual cortex. Here we have reduced this idea to practice in two species. In young mice, we show that the otherwise stable loss of cortical responsiveness caused by MD is reversed when binocular visual experience follows temporary anesthetic inactivation of the retinas. In 3-mo-old kittens, we show that a severe impairment of visual acuity is also fully reversed by binocular experience following treatment and, further, that prolonged retinal inactivation alone can erase anatomical consequences of MD. We conclude that temporary retinal inactivation represents a highly efficacious means to promote recovery of function.
authors.affiliation: Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139.
authors.forename: Ming-Fai
authors.initials: MF
authors.lastname: Fong
authors.affiliation: Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada B3H 4R2.
authors.forename: Donald E
authors.initials: DE
authors.lastname: Mitchell
authors.affiliation: Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada B3H 4R2.
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Duffy
authors.affiliation: Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139; mbear@mit.edu.
authors.forename: Mark F
authors.initials: MF
authors.lastname: Bear
mesh_terms: D000550:Amblyopia / Q000628:therapy*; D000818:Animals; D002415:Cats; D005074:Evoked Potentials, Visual; D005260:Female; D008297:Male; D051379:Mice; D023421:Models, Animal; D020127:Recovery of Function; D015349:Vision, Monocular; D014792:Visual Acuity
keywords: amblyopia; lateral geniculate nucleus; metaplasticity; ocular dominance plasticity; visual cortex