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Parkinson’s Disease
Volume 2017, Article ID 5798734, 8 pages
Research Article

Antidyskinetic Treatment with MTEP Affects Multiple Molecular Pathways in the Parkinsonian Striatum

Department of Neurology, Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, 1665 Kongjiang Road, Shanghai 200092, China

Correspondence should be addressed to Zhen-guo Liu; moc.nuyila@4002uilougnehz

Received 17 February 2017; Revised 8 May 2017; Accepted 17 September 2017; Published 30 October 2017

Academic Editor: Francisco Grandas

Copyright © 2017 Jing-ya Lin et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Parkinson’s disease is characterized by dopaminergic neuron loss and dopamine (DA) depletion in the striatum. Standard treatment is still focused on the restoration of dopamine with exogenous L-Dopa, which however causes L-Dopa-induced dyskinesia (LID). Several studies have shown that antagonism of the metabotropic glutamate receptor 5 alleviates LID, but the underlying mechanisms have remained unclear. We set out to determine where this alleviation may depend on restoring the equilibrium between the two main striatofugal pathways. For this purpose, we examined molecular markers of direct and indirect pathway involvement (prodynorphin and proenkephalin, resp.) in a rat model of LID treated with the mGluR5 antagonist MTEP. Our results show that MTEP cotreatment significantly attenuates the upregulation of prodynorphin mRNA induced by L-Dopa while also decreasing the expression levels of proenkephalin mRNA. We also examined markers of the mGluR5-related PKC/MEK/ERK1/2 signaling pathway, finding that both the expression of PKC epsilon and the phosphorylation of MEK and ERK1/2 had decreased significantly in the MTEP-treated group. Taken together, our results show that pharmacological antagonism of mGluR5 normalizes several abnormal molecular responses in the striatum in this experimental model of LID.