The effect of unilateral cortical lesions on the circadian changes in rat striatal ascorbate and homovanillic acid levels measured in vivo using voltammetry.

Linear sweep voltammograms were recorded in the striata of rats with a unilateral cortical lesion. The height of the ascorbate peak was 55% smaller on the lesioned side compared with the intact side, the homovanillic acid peak showed no significant change. The nocturnal increase in the release of striatal ascorbate was reduced by 80% on the lesioned side whilst the circadian variation in homovanillic acid was unaffected. These results support the hypothesis that there is a link between glutamate release and extracellular ascorbate concentrations in the brain.