Responsiveness of cat area 17 after monocular inactivation: limitation of topographic plasticity in adult cortex.

Rosa M.G., Schmid L.M. and Calford M.B. (1995) Responsiveness of cat area 17 after monocular inactivation: limitation of topographic plasticity in adult cortex.. The Journal of Physiology, 482 3: 589-608. doi:10.1113/jphysiol.1995.sp020543


Author Rosa M.G.
Schmid L.M.
Calford M.B.
Title Responsiveness of cat area 17 after monocular inactivation: limitation of topographic plasticity in adult cortex.
Journal name The Journal of Physiology   Check publisher's open access policy
ISSN 1469-7793
Publication date 1995-02-01
Sub-type Article (original research)
DOI 10.1113/jphysiol.1995.sp020543
Volume 482
Issue 3
Start page 589
End page 608
Total pages 20
Subject 1314 Physiology
Abstract 1. Recordings were made from neurones in the splenial sulcus of normal adult cats and adult cats which had one eye inactivated by enucleation or photocoagulation of the optic disc. Two visually responsive regions were observed, corresponding to the peripheral representation of visual area 1 (V1) and the splenial visual area. In normal animals, responses to the ipsilateral eye in V1 were restricted to the medial half of the splenial sulcus, up to 45‐50 deg eccentricity. Thus, by inactivating the eye contralateral to the experimental hemisphere, we created a region in V1, 1‐2 mm wide, that lacked normal inputs. 2. In contrast to results from previous experiments where lesions were placed in the central retina, neurones in the deprived peripheral representation remained unresponsive to light stimuli for up to 12 h after deactivation of the contralateral eye. 3. In animals that were allowed to recover from the monocular deactivation for periods of 2 days to 16 months, there was rearrangement of the retinotopic maps. Receptive fields in regions of cortex that normally represented the monocular crescent were displaced to the temporal border of the binocular field of vision. However, most neurones in the deprived peripheral representation remained unresponsive to visual stimuli even more than 1 year after treatment. This is also in marked contrast with the extensive reorganization that is observed in the central representation of V1 after restricted retinal lesions. Analysis of the cortical magnification factor demonstrates that the change in visual topography is local, and does not involve an overall centro‐peripheral shift of the retinotopic map. 4. Among the neurones that did show displaced receptive fields, the response properties were clearly abnormal. They showed a notable lack of spontaneous activity, low firing rates and rapid habituation to repeated stimulation. 5. The low potential for reorganization of the monocular sector of V1 demonstrates that the capacity for plasticity of mature sensory representations varies with location in cortex. Even relatively small pieces of cortex, such as the monocular crescent representations, may not reorganize completely if certain conditions are not met. These results suggest the existence of natural boundaries that may limit the process of reorganization of sensory representations.
Q-Index Code C1
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: Scopus Import - Archived
 
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