The number of dopaminergic cells is increased in the olfactory bulb of monkeys chronically exposed to MPTP
Belzunegui S, San Sebastián W, Garrido-Gil P, Izal-Azcárate A, Vázquez-Claverie M, López B, Marcilla I, Lanciego JL, Luquin MR.
Laboratory of Regenerative Therapy, Department of Neuroscience, Center for Applied Medicine Research, University of Navarra, Avenida Pío XII 55, 31008. Pamplona, Navarra, Spain.
We investigated the impact of the nigrostriatal lesion on the olfactory tyrosine hydroxylase-immunoreactive (TH-ir) cells in monkeys.
The majority of these TH-ir cells appeared in the glomerular layer of the olfactory bulb and many were immature but functional dopaminergic neurons. In parkinsonian monkeys the number of olfactory dopaminergic neurons increased up to 100% as compared to controls, but their phenotype did not change.
This increased TH-ir cell population might be a direct consequence of the nigral cell loss and contribute to the hyposmia reported by Parkinson's disease patients.
CITATION Synapse. 2007 Dec;61(12):1006-12