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Effect of sensory deafferentation on immunoreactivity of GABAergic cells and on GABA receptors in the adult cat visual cortex
Author(s) -
Rosier A. M.,
Arckens L.,
Demeulemeester H.,
Orban G. A.,
Eysel U. T.,
Wu Y.J.,
Vandesande F.
Publication year - 1995
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.903590309
Subject(s) - cats , gabaergic , glutamate decarboxylase , visual cortex , biology , muscimol , gabaa receptor , gamma aminobutyric acid , inhibitory postsynaptic potential , sensory system , neuroscience , receptor , cortex (anatomy) , medicine , endocrinology , biochemistry , enzyme
To investigate the effects of sensory deafferentation on the cortical GABAergic circuitry in adult cats, glutamic acid decarboxylase (GAD) and gamma‐aminobutyric acid (GABA) immunoreactivity and GABA receptor binding were studied in the visual cortex of normal cats and compared with cats that had received restricted binocular central lesions of the retina and had survived for 2 weeks postlesion in a normal visual environment. In the visual cortex of lesioned cats, two changes were observed in the number of GAD‐immunoreactive elements in the regions affected by the retinal lesions: the number of GAD‐positive puncta decreased, whereas that of GAD‐immunoreactive somata increased. In contrast, no detectable changes were measured in the number of GABA‐immunopositive somata or puncta. At the receptor level, we observed no differences in either the laminar distribution or the affinity of cortical GABA A and GABA B receptors labeled with [ 3 H]‐muscimol and [ 3 H]‐baclofen, respectively, in the lesioned versus normal cats. We present the hypothesis that sensory deafferentation in these adult cats (1) leads to a reduction of cortical GABAergic inhibition in the deafferented region, and (2) that this decreased inhibition may permit changes in efficiency of synapses and (3) that these changes may represent a first stage of events underlying the retinotopic reorganization preceeding the structural changes. © 1995 Wiley‐Liss, Inc.