title: Quantification of early stages of cortical reorganization of the topographic map of V1 following retinal lesions in monkeys.
abstract: We quantified the capacity for reorganization of the topographic representation of area V1 in adult monkeys. Bias-free automated mapping methods were used to delineate receptive fields (RFs) of an array of neuronal clusters prior to, and up to 6 h following retinal lesions. Monocular lesions caused a significant reorganization of the topographic map in this area, both inside and outside the cortical lesion projection zone (LPZ). Small flashed stimuli revealed responses up to 0.85 mm inside the boundaries of the LPZ, with RFs representing regions of undamaged retina immediately surrounding the lesion. In contrast, long moving bars that spanned the scotoma resulting from the lesion revealed responsive units up to 1.87 mm inside the LPZ, with RFs representing interpolated responses in this region. This reorganization is present immediately after monocular retinal lesioning. Both stimuli showed a similar and significant (5-fold) increase of the RF scatter in the LPZ, 0.56 mm (median), compared with the undamaged retina, 0.12 mm. Our results reveal an array of preexisting subthreshold functional connections of up to 2 mm in V1, which can be rapidly mobilized independently from the differential qualitative reorganization elicited by each stimulus.
authors.affiliation: Programa de Neurobiologia, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro, RJ 21941-900, Brazil.
authors.forename: Eliã P
authors.initials: EP
authors.lastname: Botelho
authors.forename: Cecília
authors.initials: C
authors.lastname: Ceriatte
authors.forename: Juliana G M
authors.initials: JG
authors.lastname: Soares
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gattass
authors.forename: Mario
authors.initials: M
authors.lastname: Fiorani
mesh_terms: D000818:Animals; D001931:Brain Mapping; D002428:Cebus; D004569:Electroencephalography; D055724:Electrophysiological Phenomena / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D010775:Photic Stimulation; D012160:Retina / Q000293:injuries* / Q000502:physiology; D059629:Signal-To-Noise Ratio; D014793:Visual Cortex / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology; D014795:Visual Pathways / Q000502:physiology