Changes in brain glucose metabolism following traumatic optic neuropathy in rats.

This study investigated whether an optic neuropathy results in changes of brain glucose metabolism using 2-deoxy-2-F-18 fluoro-D-glucose (F-18 FDG) positron emission tomography (PET) scan. Optic nerves were crushed in the left eye of four male Sprague–Dawley rats, which were examined using F-18 FDG PET 7 days before and after surgery for a total of 5 weeks. We calculated the standardized uptake value ratio and analyzed relative changes in the visual cortex, thalamus, hypothalamus, and superior colliculus over time. The glucose metabolism in both visual cortices elevated after an optic nerve injury. A trend towards higher glucose metabolism, reaching significance 2 weeks following the procedure, was observed in the right visual cortical areas compared with those in the left hemisphere. The standardized uptake value ratios of both thalami significantly increased in 2 weeks as compared with the baseline. Other brain regions showed no significant changes. Traumatic optic neuropathy in rats causes asymmetrical elevation in brain glucose metabolism in the visual cortex, while the observed changes in the thalami as compared with baseline were similar in both hemispheres of the rat brain. [ABSTRACT FROM AUTHOR]