Please use this identifier to cite or link to this item: http://ahro.austin.org.au/austinjspui/handle/1/10514
Title: Evidence for plasticity of the dopaminergic system in parkinsonism.
Authors: Donnan, Geoffrey A;Woodhouse, D G;Kaczmarczyk, S J;Holder, J E;Paxinos, G;Chilco, P J;Churchyard, A J;Kalnins, Renate M;Fabinyi, Gavin;Mendelsohn, Frederick AO
Affiliation: Department of Neurology, Austin Hospital, Heidelberg, Victoria, Australia.
Issue Date: 16-May-1991
Citation: Molecular Neurobiology; 5(2-4): 421-33
Abstract: A series of compensatory mechanisms within the dopaminergic system have been shown to maintain clinical function in the presence of dopamine loss. Experimental evidence for increased presynaptic dopamine turnover owing to increased dopamine synthesis, release, and reduced reuptake exists. Direct evidence that these mechanisms maintain extracellular dopamine levels is provided by intracerebral microdialysis techniques. Postsynaptic denervation supersensitivity clearly occurs with D2 dopamine receptors, although this is less evident with D1 receptors. Similarly, mechanisms of plasticity have been shown to be relevant in human postmortem and Positron Emission Tomographic studies of patients with Parkinson's disease. However, although presynaptic increases in dopamine turnover are well documented, postsynaptic D1 and D2 receptor changes have been more difficult to establish, mainly because of methodological difficulties. D2, but not D1, receptor increases have been documented in drug naive Parkinsonian patients with PET techniques. In transplantation of adrenal gland to striatum in animal models and patients with Parkinsonism where clinical improvement occurs, plasticity of host response may be as important as plasticity of the graft. Although some elements of the compensatory mechanism of dopamine plasticity may be deleterious, such as dyskinesias owing to dopamine receptor supersensitivity, the overall effect of delay and minimization of the clinical expression of disease is advantageous. An even greater understanding of the mechanisms involved may assist in developing future therapeutic strategies.
Internal ID Number: 1823144
URI: http://ahro.austin.org.au/austinjspui/handle/1/10514
URL: http://www.ncbi.nlm.nih.gov/pubmed/1823144
Type: Journal Article
Subjects: Adrenal Glands.transplantation
Adult
Aged
Animals
Corpus Striatum.metabolism.physiopathology.radionuclide imaging
Denervation
Dopamine.metabolism.physiology
Humans
Mice
Mice, Inbred C57BL
Middle Aged
Neuronal Plasticity
Neurotoxins.toxicity
Parkinson Disease.metabolism.physiopathology.radionuclide imaging.surgery
Parkinson Disease, Secondary.metabolism.physiopathology.surgery
Rats
Receptors, Dopamine.metabolism.physiology
Synapses.physiology
Tomography, Emission-Computed
Transplantation, Heterotopic
Appears in Collections:Journal articles

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