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Abstract #9110 Published in IGR 5-2
Neurochemical correlates of cortical plasticity after unilateral elevated intraocular pressure in a primate model of glaucoma
Lam DY; Kaufman PL; Gabelt BT; To EC; Matsubara JAInvestigative Ophthalmology and Visual Science 2003; 44: 2573-2581
PURPOSE: To examine the time course of changes in the expression patterns of several synaptic plasticity markers in the primary visual cortex after unilateral elevated intraocular pressure (IOP) in a primate model of glaucoma. METHODS: A monkey model of experimental glaucoma was combined with immunohistochemical and histochemical methods to assess changes in expression patterns and metabolic activity of cortical neurons in V1. RESULTS: Experimental unilateral glaucoma altered the spatial and temporal distribution of several neurochemicals associated with cortical plasticity in V1 of the primate. Within-animal comparisons of immunohistochemical studies revealed that GABAa receptor protein and GAP-43 were significantly lower in glaucomatous versus normal eye bands after two, four, and seven months of elevated IOP. SYN immunoreactivity was also lower in the glaucomatous versus the normal eye bands but only at four months of elevated IOP. CAMKIIα immunoreactivity levels were higher in the glaucomatous versus the normal eye bands. Between-animal comparisons revealed that the levels of GAP-43 and SYN were up-regulated, whereas levels of GABAa receptor protein were down-regulated, in glaucomatous eyes when compared with levels in the visual cortex of normal animals. CONCLUSIONS: Unilateral elevation of IOP affects both the metabolic activity of cortical neurons and the expressed levels of GAP-43, SYN, GABAa receptor protein, and CAMKIIα, as measured immunohistochemically in the primary visual cortex of adult monkeys. Because these neurochemicals are thought to be necessary for synaptic plasticity, their redistribution may support functional recovery of cortical neurons after damage to retinal ganglion cells induced by elevated IOP.
Dr. D.Y. Lam, Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC, Canada
Classification:
2.16 Chiasma and retrochiasmal central nervous system (Part of: 2 Anatomical structures in glaucoma)
3.3 Immunohistochemistry (Part of: 3 Laboratory methods)
5 Experimental glaucoma; animal models
