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Updated: Oct 11, 2026

Rating L-DOPA-Induced Dyskinesias in the Unilaterally 6-OHDA-Lesioned Rat Model of Parkinson's Disease
Published on: October 4, 2021
TH protein and mRNA in nigrostriatal dopaminergic neurons are down-regulated by continuous but not intermittent
1Department of Pharmacology, Faculty of Medicine, Kagoshima University, 890-8520, Kagoshima, Japan. shinichi@m.kufln.kagoshima-u.ac.jp
Abstract:
Levels of tyrosine hydroxylase (TH) and TH mRNA were measured after administration of dopamine agonists for a long period of time to elucidate the long-term feedback inhibition of dopamine synthesis in nigrostriatal dopaminergic neurons. Continuous infusion, which desensitized presynaptic dopamine receptors, but not repeated administration, down-regulated TH and TH mRNA levels. This suggests levels of TH protein and mRNA are only feedback inhibited by the continuous stimulation of postsynaptic dopamine receptors.
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