6-[18F]fluoro-L-dopa and cerebral blood flow in unilaterally MPTP-treated monkeys.

Intravenous administration of 15O-labeled water and 6-[18F]-L-fluorodopa were used to assess abnormal striatal activity in monkeys after long-term recovery of unilateral lesions of the dopaminergic nigro-striatal system induced by the neurotoxin MPTP. PET data were examined in relation to behavioral and biological parameters. Cerebral blood flow and 6-[18F]-L-DOPA uptake were found to be significantly reduced in the lesioned striatum, compared to the unaffected side and to normal controls.

D-dopa and L-dopa similarly elevate brain dopamine and produce turning behavior in rats.

In the intact rat, intragastric administration of D-dihydroxyphenylalanine (D-DOPA) together with carbidopa (alpha-methyldopa hydrazine, a peripheral dopadecarboxylase inhibitor) increased striatal dopamine concentration to the same extent as a similar treatment with L-DOPA plus carbidopa. In rats with unilateral 6-hydroxydopamine-induced lesions of their substantia nigra, both stereoisomers of DOPA produced significant increases in dopamine and its metabolites in the intact striata. Although dopamine concentrations in the lesioned striata did not change, a significant increase in dopamine metabolites was observed, indicating some extraneuronal formation of dopamine.

Poor premorbid adjustment and CT scan abnormalities in chronic schizophrenia.

The authors evaluated the premorbid adjustment of 51 chronic schizophrenic patients by retrospective chart analysis using a novel scale. Those patients with CT evidence suggestive of brain atrophy had significantly worse premorbid scores, particularly during childhood, than did the patients with normal scans. This finding provides further support for the clinical relevance of CT findings in chronic schizophrenic patients and implicates a neuropathological process that occurs early in development.