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Lentiviral delivery of glial cell line-derived neurotrophic factor (lenti-GDNF) was tested for its trophic effects upon degenerating nigrostriatal neurons in nonhuman primate models of Parkinson's disease (PD). We injected lenti-GDNF into the striatum and substantia nigra of nonlesioned aged rhesus monkeys or young adult rhesus monkeys treated 1 week prior(More)
The role of the amygdala in major depression was investigated. Resting regional cerebral metabolic rate (rCMRglu) was measured with [18F]fluorodeoxyglucose positron emission tomography (PET) in two samples of subjects using two different PET cameras. The samples consisted of 10 and 17 medication-free depressives and 11 and 13 controls, respectively. Using(More)
Severe and prolonged physical and psychological stress is known to cause brain damage; long-term torture victims in prison have later developed psychiatric disorders and cerebral cortical atrophy observed in CT scans (Jensen, Genefke, Hyldebrandt, Pedersen, Petersen, and Weile, 1982). In nonhuman primates, we observed degeneration and depletion of the(More)
Although the role of dopamine dysfunction is well established in Parkinson's disease, the effect of nigrostriatal degeneration on motor performance during normal aging is less well understood. In this study, aged rhesus monkeys (25-27 years old) displayed significant impairments relative to young (3-5 years old) cohorts in motor function as assessed on a(More)
Clinical symptoms of Parkinson's disease (PD) do not manifest until dopamine (DA) neuronal loss reaches a symptomatic threshold. To explore the mechanisms of functional compensation that occur in presynaptic DA nerve terminals in PD, we compared striatal positron emission tomographic (PET) measurements by using [11C]dihydrotetrabenazine ([11C]DTBZ; labeling(More)
Motor fluctuations are a major disabling complication in the treatment of Parkinson's disease. To investigate whether such oscillations in mobility can be attributed to changes in the synaptic levels of dopamine, we studied prospectively patients in the early stages of Parkinson's disease with a follow-up after at least 3 years of levodopa treatment. At(More)
OBJECTIVE To evaluate the visible and quantitative anatomic distribution of fluorine-18-labeled L-DOPA in the healthy human brain, to thereby expand the understanding of extrastriatal sites of levodopa function, and to provide a broader foundation for clinical and research studies of fluoroDOPA accumulation in patients. METHODS The authors performed(More)
The authors developed a novel positron emission tomography method to estimate changes in the synaptic level of dopamine ([DA]) induced by direct dopamine agonists (for example, apomorphine) in patients with Parkinson disease. The method is based on the typical asymmetry of the nigrostriatal lesion that often occurs in Parkinson disease. Using the(More)
Electroencephalogram (EEG) alpha power has been demonstrated to be inversely related to mental activity and has subsequently been used as an indirect measure of brain activation. The thalamus has been proposed as an important site for modulation of rhythmic alpha activity. Studies in animals have suggested that cortical alpha rhythms are correlated with(More)