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Topographic plasticity in primary visual cortex is mediated by local corticocortical connections


Calford, MB and Wright, LL and Metha, AB and Taglianetti, V, Topographic plasticity in primary visual cortex is mediated by local corticocortical connections, Journal of Neuroscience, 23, (16) pp. 6434-6442. ISSN 0270-6474 (2003) [Refereed Article]


The placement of monocular laser lesions in the adult cat retina produces a lesion projection zone (LPZ) in primary visual cortex (V1) in which the majority of neurons have a normally located receptive field (RF) for stimulation of the intact eye and an ectopically located RF (displaced to intact retina at the edge of the lesion) for stimulation of the lesioned eye. Animals that had such lesions for 14-85 d were studied under halothane and nitrous oxide anesthesia with conventional neurophysiological recording techniques and stimulation of moving light bars. Previous work suggested that a candidate source of input, which could account for the development of the ectopic RFs, was long-range horizontal connections within V1. The critical contribution of such input was examined by placing a pipette containing the neurotoxin kainic acid at a site in the normal VI visual representation that overlapped with the ectopic RF recorded at a site within the LPZ. Continuation of well defined responses to stimulation of the intact eye served as a control against direct effects of the kainic acid at the LPZ recording site. In six of seven cases examined, kainic acid deactivation of neurons at the injection site blocked responsiveness to lesioned-eye stimulation at the ectopic RF for the LPZ recording site. We therefore conclude that long-range horizontal projections contribute to the dominant input underlying the capacity for retinal lesion-induced plasticity in V1.

Item Details

Item Type:Refereed Article
Keywords:Adult brain plasticity; Area 17; Cortical reorganization; Ectopic receptive fields; Horizontal connections; Retinal lesion; halothane; kainic acid; nitrous oxide; animal experiment; animal tissue; article; cat; controlled study; Cats
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Neurology and neuromuscular diseases
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Calford, MB (Professor Mike Calford)
ID Code:91296
Year Published:2003
Web of Science® Times Cited:59
Deposited By:Research Division
Deposited On:2014-05-13
Last Modified:2014-05-13

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