title: Calcium-permeable AMPA receptors are involved in the induction and expression of l-DOPA-induced dyskinesia in Parkinson's disease.
abstract: Overactivity of striatal alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptors is implicated in the pathophysiology of L-DOPA-induced dyskinesia (LID) in Parkinson's disease (PD). In this study, we evaluated the behavioural and molecular effects of acute and chronic blockade of Ca(2+)-permeable AMPA receptors in animal models of PD and LID. The acute effects of the Ca(2+)-permeable AMPA receptor antagonist 1-trimethylammonio-5-(1-adamantane-methylammoniopentane) dibromide hydrobromide (IEM 1460) on abnormal involuntary movements (AIMs) in the 6-hydroxydopamine (6-OHDA)-lesioned rat and LID in the MPTP-lesioned non-human primate were assessed. Subsequently, the effects of chronic treatment of 6-OHDA-lesioned rats with vehicle, L-DOPA/benserazide (6/15 mg/kg, i.p.) + vehicle or L-DOPA + IEM 1460 (3 mg/kg, i.p.) on behavioural and molecular correlates of priming for LID were evaluated. In the 6-OHDA-lesioned rat and MPTP-lesioned non-human primate, acute treatment with IEM 1460 (1-3 mg/kg) dose-dependently reduced LID without adverse effects on motor performance. Chronic co-treatment for 21 days with IEM 1460 reduced the induction of AIMs by L-DOPA in the 6-OHDA-lesioned rat without affecting peak rotarod performance, and attenuated AIMs score by 75% following l-DOPA challenge (p < 0.05). Chronic IEM 1460 treatment reversed L-DOPA-induced up-regulation of pre-proenkephalin-A, and normalised pre-proenkephalin-B mRNA expression in the lateral striatum, indicating an inhibition of both behavioural and molecular correlates of priming. These data suggest that Ca(2+)-permeable AMPA receptors are critically involved in both the induction and subsequent expression of LID, and represent a potential target for anti-dyskinetic therapies.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, UK. christopher.kobylecki@manchester.ac.uk
authors.forename: Christopher
authors.initials: C
authors.lastname: Kobylecki
authors.forename: M Angela
authors.initials: MA
authors.lastname: Cenci
authors.forename: Alan R
authors.initials: AR
authors.lastname: Crossman
authors.forename: Paula
authors.initials: P
authors.lastname: Ravenscroft
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000978:Antiparkinson Agents / Q000009:adverse effects*; D001522:Behavior, Animal / Q000187:drug effects*; D001545:Benserazide / Q000009:adverse effects; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002144:Callithrix; D004409:Dyskinesia, Drug-Induced / Q000209:etiology / Q000378:metabolism / Q000523:psychology*; D004745:Enkephalins / Q000096:biosynthesis; D007980:Levodopa / Q000009:adverse effects*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D016627:Oxidopamine; D010300:Parkinson Disease / Q000188:drug therapy* / Q000209:etiology / Q000378:metabolism; D011498:Protein Precursors / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000502:physiology*
chemical_list: D000978:Antiparkinson Agents; D004745:Enkephalins; C110702:IEM 1460; D011498:Protein Precursors; D018091:Receptors, AMPA; D007980:Levodopa; D001545:Benserazide; D016627:Oxidopamine; C033660:preproenkephalin; D000218:Adamantane; D002118:Calcium