Doris Doudet

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1. Individual neurons were recorded extracellularly in the precentral forelimb area of two monkeys trained to perform rapid, large amplitude flexion and extension movements of the contralateral forearm in response to auditory signals. Electromyographic (EMG) activity in the biceps/triceps muscles was recorded separately under the same conditions. The(More)
This report describes the presence of reactive microglia, the accumulation of extracellular melanin, and the extensive loss of dopaminergic neurons in the substantia nigra of monkeys administered 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) 5 to 14 years before death. This evidence of chronic neuroinflammation years after MPTP exposure is similar to(More)
Movement parameters and electromyographic (EMG) studies were carried out in two macaque monkeys performing a rapid arm movement before and after administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Hypokinesia and rigidity were seen after repeated doses. Disturbances in both movements and EMG activity were similar to those reported in(More)
Using MRI and PET, we investigated the consequences of manganese intoxication in a primate model of parkinsonism and dystonia. Three rhesus monkeys were injected intravenously with doses of 10 to 14 mg/kg of MnCl2 on seven occasions, each a week apart. Two animals became hypoactive with abnormal extended posturing in the hind limbs. These motor disturbances(More)
UNLABELLED The reproducibility of (+/-)-alpha-[11C] dihydrotetrabenazine (DTBZ) measures in PET was studied in 10 healthy human subjects, aged 22-76 y. METHODS The scan-to-scan variation of several measures used in PET data analysis was determined, including the radioactivity ratio (target-to-reference), plasma-input Logan total distribution volume (DV),(More)
BACKGROUND Lesch-Nyhan disease is a rare, devastating, X-linked recessive disorder of purine synthesis. Patients present with hyperuricemia, choreoathetosis, dystonia, and aggressive and self-injurious behavior. Although the genetic and biochemical abnormalities have been identified, the causes of the neuropsychiatric syndrome remain unclear. METHODS We(More)
Human retinal pigment epithelial (hRPE) cells are dopaminergic support cells in the neural retina. Stereotaxic intrastriatal implantation of hRPE cells attached to gelatin microcarriers (Spheramine) in rodent and non-human primate models of Parkinson's disease (PD) produces long term amelioration of motor and behavioral deficits, with histological and PET(More)
Human retinal pigment epithelial (hRPE) cells produce L-dopa, are easily harvested and expanded in culture, and, attached to microcarriers, can survive in the brain without immunosuppression. Studies in rats, primates, and parkinsonian patients have demonstrated that striatally implanted hRPE cells attached to gelatin microcarriers (RPE-GM) are able to(More)
Changes in dopamine turnover resulting from disease states such as Parkinson's disease may be reflected in corresponding changes in the kinetics of the positron emission tomographic tracer [(18)F]fluorodopa. The authors had previously refined the conventional irreversible-tracer graphical approach to determine both the uptake rate constant K(i) and the rate(More)
Positron emission tomography was performed on 12 Alzheimer's patients and 12 age-matched normal controls following the administration of the opiate receptor antagonist 6-deoxy-6-beta-[18F]fluoronaltrexone (cyclofoxy, CF). Tracer kinetic analysis was used to determine the volume of distribution of CF, a measure of unoccupied mu and kappa receptor density,(More)