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Parkinson’s Disease
Volume 2010 (2010), Article ID 238491, 6 pages
http://dx.doi.org/10.4061/2010/238491
Research Article

Effects of SR141716A on Cognitive and Depression-Related Behavior in an Animal Model of Premotor Parkinson's Disease

1Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, Trindade, Bloco D/CCB, P.O. Box 476, 88040-970 Florianópolis, SC, Brazil
2Laboratório de Fisiologia e Farmacologia do Sistema Nervoso Central, Setor de Ciências Biológicas, Universidade Federal do Paraná (UFPR), Centro Politécnico, 81531-980 Curitiba, PR, Brazil

Received 25 March 2010; Revised 16 July 2010; Accepted 31 August 2010

Academic Editor: Alan R. Crossman

Copyright © 2010 M. T. Tadaiesky 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.

Abstract

A previous study from our laboratory revealed that moderate nigral dopaminergic degeneration caused emotional and cognitive deficits in rats, paralleling early signs of Parkinson's disease. Recent evidence suggests that the blockade of cannabinoid CB1 receptors might be beneficial to alleviate motor inhibition typical of Parkinson's disease. Here, we investigated whether antagonism of CB1 receptors would improve emotional and cognitive deficits in a rat model of premotor Parkinson's disease. Depression-like behavior and cognition were assessed with the forced swim test and the social recognition test, respectively. Confirming our previous study, rats injected with 6-hydroxydopamine in striatum presented emotional and cognitive alterations which were improved by acute injection of SR141716A. HPLC analysis of monoamine levels demonstrated alterations in the striatum and prefrontal cortex after SR141716A injection. These findings suggest a role for CB1 receptors in the early symptoms caused by degeneration of dopaminergic neurons in the striatum, as observed in Parkinson's disease.