Effect of sensory deafferentation on the GABAergic circuitry of the adult cat visual system

• Published in: Neuroscience Vol. 83; no. 2; pp. 381 - 391
• Main Authors: Arckens, L, Eysel, U.T, Vanderhaeghen, J.-J, Orban, G.A, Vandesande, F
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-03-1998; Elsevier
• Subjects: Animals; A–P, antero–posterior; Biological and medical sciences; cat; Cats; Denervation; dLGN; dLGN, dorsal lateral geniculate nucleus; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; GAD; GAD, glutamate decarboxylase; gamma-Aminobutyric Acid - physiology; Geniculate Bodies - metabolism; GFAP, glial fibrillary acid protein; Glutamate Decarboxylase - metabolism; Immunohistochemistry; In Situ Hybridization; Neurons, Afferent - physiology; Ocular Physiological Phenomena; Oligonucleotide Probes; PGN, perigeniculate nucleus; Retina - cytology; Retina - physiology; RNA, Messenger - biosynthesis; SSC, standard saline citrate; topographic re-organization; Vertebrates: nervous system and sense organs; visual cortex; Visual Cortex - physiology; dLGN; dLGN, dorsal lateral geniculate nucleus; visual cortex; cat; GAD, glutamate decarboxylase; PGN, perigeniculate nucleus; SSC, standard saline citrate; GAD; A–P, antero–posterior; topographic re-organization; GFAP, glial fibrillary acid protein; in situ hybridization; Fissipedia; Carnivora; Visual cortex; Enzyme; Central nervous system; Lyases; Glutamate decarboxylase; Visual system; Carbon-carbon lyases; Vertebrata; Mammalia; Visual pathway; Carboxy-lyases; Topography; Cat; Neurotransmitter; GABA; Deafferentation; Brain (vertebrata)
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/S0306-4522(97)00422-3

The effect of bilateral central retinal lesions on the GAD67 and GAD65 messenger RNA levels in the dorsal lateral geniculate nucleus, the perigeniculate nucleus and the visual cortex of the adult cat was investigated by in situ hybridization. Three days post-lesion, a decrease in the number of GAD67-expressing cells was apparent in the deafferented dorsal lateral geniculate nucleus. This decrease persisted until 7.5 months post-lesion and was more pronounced with longer survival times. The decrease in GAD67 mRNA was mirrored by a decrease in glutamate decarboxylase-immunoreactive cells. GAD65 messenger RNA expression levels were low in the dorsal lateral geniculate nucleus of both control and retinally-lesioned cats. In the perigeniculate nucleus the messenger RNA levels of both glutamate decarboxylase isoforms were clearly decreased over a restricted region. In the lesion-affected visual cortex, no changes at the messenger RNA level were observed for either GAD67 or GAD65 although changes in glutamate decarboxylase immunoreactivity have been previously described.[34]
Hence, in the dorsal lateral geniculate nucleus, the perigeniculate nucleus and the visual cortex, different intracellular mechanisms seem to lead to decreased GABAergic inhibition in response to sensory deafferentation.