Presymptomatic compensation in Parkinson's disease is not dopamine-mediated.
The symptoms of Parkinson's disease (PD) appear only after substantial degeneration of the dopaminergic neuron system (e.g. an 80% depletion of striatal dopamine)--that is, there is a substantive presymptomatic period of the disease. It is widely believed that dopamine-related compensatory mechanisms are responsible for delaying the appearance of symptoms. Recent advances in understanding the presymptomatic phase of PD have increased our understanding of these dopamine-related compensatory mechanisms and have highlighted the role of non-dopamine-mediated mechanisms both within and outside the basal ganglia. This increased knowledge of plasticity within cortical-basal-ganglia-thalamocortical circuitry as dopaminergic neuron degeneration progresses has implications for understanding plasticity in neural circuits generally and, more specifically, for developing novel therapeutics or presymptomatic diagnostics for PD.
Bezard
Erwan
E
Basal Gang, Laboratoire de Neurophysiologie, CNRS UMR 5543, Université Victor Segalen, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France. erwan.bezard@umr5543.u-bordeaux2.fr
Gross
Christian E
CE
Brotchie
Jonathan M
JM
D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001479:Basal Ganglia / Q000503:physiopathology; D018450:Disease Progression; D004298:Dopamine / Q000378:metabolism*; D004745:Enkephalins / Q000235:genetics / Q000378:metabolism; D005917:Globus Pallidus / Q000503:physiopathology; D006801:Humans; D008959:Models, Neurological; D010300:Parkinson Disease / Q000378:metabolism / Q000503:physiopathology*; D017448:Receptors, Dopamine D2 / Q000502:physiology; D013378:Substantia Nigra / Q000503:physiopathology
D004745:Enkephalins; D017448:Receptors, Dopamine D2; D004298:Dopamine