title: Effect of chronic L-dopa or melatonin treatments after dopamine deafferentation in rats: dyskinesia, motor performance, and cytological analysis.
abstract: The present study examines the ability of melatonin to protect striatal dopaminergic loss induced by 6-OHDA in a rat model of Parkinson's disease, comparing the results with L-DOPA-treated rats. The drugs were administered orally daily for a month, their therapeutic or dyskinetic effects were assessed by means of abnormal involuntary movements (AIMs) and stepping ability. At the cellular level, the response was evaluated using tyrosine hydroxylase immunoreactivity and striatal ultrastructural changes to compare between L-DOPA-induced AIMs and Melatonin-treated rats. Our findings demonstrated that chronic oral administration of Melatonin improved the alterations caused by the neurotoxin 6-OHDA. Melatonin-treated animals perform better in the motor tasks and had no dyskinetic alterations compared to L-DOPA-treated group. At the cellular level, we found that Melatonin-treated rats showed more TH-positive neurons and their striatal ultrastructure was well preserved. Thus, Melatonin is a useful treatment to delay the cellular and behavioral alterations observed in Parkinson's disease.
authors.affiliation: Laboratorio de Neuromorfologia, Departamento de Neurociencias, Facultad de Estudios Superiores Iztacala, UNAM, Avenida de los Barrios 1, Los Reyes Iztacala, 54090 Tlalnepantla, MEX, Mexico.
authors.forename: Ana Luisa
authors.initials: AL
authors.lastname: Gutierrez-Valdez
authors.forename: Verónica
authors.initials: V
authors.lastname: Anaya-Martínez
authors.forename: José Luis
authors.initials: JL
authors.lastname: Ordoñez-Librado
authors.forename: Ricardo
authors.initials: R
authors.lastname: García-Ruiz
authors.forename: Carmen
authors.initials: C
authors.lastname: Torres-Esquivel
authors.forename: Montserrat
authors.initials: M
authors.lastname: Moreno-Rivera
authors.forename: Javier
authors.initials: J
authors.lastname: Sánchez-Betancourt
authors.forename: Enrique
authors.initials: E
authors.lastname: Montiel-Flores
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Avila-Costa