title: Orientation-restricted continuous visual exposure induces marked reorganization of orientation maps in early life.
abstract: To elucidate the effect of visual experience on the development of orientation maps, we conducted intrinsic signal optical imaging of the visual cortex of kittens that were continuously exposed to a single orientation through cylindrical-lens-fitted goggles under a freely moving condition starting at post-natal week 3. We observed a rapid reorganization of orientation maps, characterized by extensive representation of exposed orientations with reduced responsiveness to unexposed orientations. The over-representation of exposed orientation was marked for 1-2 weeks of goggle rearing. A longer period of goggle rearing, however, decreased the degree of over-representation, which still remained at a remarkable level. Dark rearing episodes daily interleaved between single orientation exposures moderated the over-representation effect. Unit recording from goggle-reared kittens showed preferred orientations consistent with optical imaging. Using c-Fos immunoreactivity mapping, we showed that the number of neurons strongly responding to the exposed orientation was 3 times larger in a goggle-reared cat than the number of neurons responding to the vertical orientation in a normal cat. Taken together, these results suggest that the reorganization of orientation maps was caused by the expansion of domains maximally responding to exposed orientation as well as the strong reduction of responses to unexposed orientations.
authors.affiliation: Laboratory for Visual Neurocomputing, Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. shigeru@riken.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tanaka
authors.forename: Jérôme
authors.initials: J
authors.lastname: Ribot
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Imamura
authors.forename: Toshiki
authors.initials: T
authors.lastname: Tani
mesh_terms: D000465:Algorithms; D000818:Animals; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D002415:Cats; D004567:Electrodes, Implanted; D004594:Electrophysiology; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008027:Light; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology
chemical_list: D016760:Proto-Oncogene Proteins c-fos