Experimental glaucoma in primates: changes in cytochrome oxidase blobs in V1 cortex.
OBJECTIVE
To evaluate the effects of ganglion cell depletion from experimental glaucoma on the relative metabolic activities of neurons in the cytochrome oxidase blobs of V1 cortex in the macaque visual system.


METHODS
Monocular experimental glaucoma was induced in adult monkeys (Macaca mulatta and Macaca fascicularis) by laser application to the trabecular meshwork, increasing the intraocular pressure. After other experiments, the primary visual cortices were analyzed for functional excitation from surviving ganglion cells, as indicated by cytochrome oxidase histochemistry.


RESULTS
Cytochrome oxidase reactivity was uniformly reduced in blobs with input from the glaucomatous eye in a manner consistent with loss of known afferent inputs. The average size of glaucomatous blobs in layers 2 and 3 of V1 cortex was reduced by half.


CONCLUSIONS
Experimental glaucoma in monkeys reduces retinal input to the central nervous system, thereby reducing the metabolic drive to downstream targets, as indicated by the reduction in the size of cytochrome oxidase blobs in layers 2 and 3 of V1 cortex. The pattern of cytochrome oxidase loss within the blob was uniform, suggesting that all sources of afferent input to the blobs were affected by experimental glaucoma.
Crawford
M L
ML
Department of Ophthalmology and Visual Science, University of Texas Medical School at Houston, 77030, USA. morris.l.crawford@uth.tmc.edu
Harwerth
R S
RS
Smith
E L
EL
Mills
S
S
Ewing
B
B
D000344:Afferent Pathways / Q000201:enzymology; D000818:Animals; D004195:Disease Models, Animal; D003576:Electron Transport Complex IV / Q000378:metabolism*; D005901:Glaucoma / Q000201:enzymology*; D053685:Laser Therapy; D008252:Macaca fascicularis; D008253:Macaca mulatta; D009474:Neurons / Q000201:enzymology; D012165:Retinal Ganglion Cells / Q000201:enzymology; D014129:Trabecular Meshwork / Q000601:surgery; D014793:Visual Cortex / Q000201:enzymology*; D014794:Visual Fields
D003576:Electron Transport Complex IV