A rat model of the cognitive impairments in Parkinson’s disease

CLAUDIO DA CUNHA, RUI D. S. PREDIGER, EDMAR MIYOSHI, REINALDO N. TAKAHASHI

Abstract


Although Parkinson’s disease (PD) is classically considered to be a motor system disease, subtle cognitive impairments can be observed even during the early phases of PD. In this article we review behavioral and neurochemical studies on the cognitive alterations observed in rats treated with intranigral infusion of the neurotoxin MPTP. The critical role of dopamine release in the dorsal striatum and its modulation by adenosine receptors is also reviewed as a potential strategy to treat the cognitive disabilities of PD patients who do not improve with levodopa therapy. Most of the impairments presented by rats treated with intranigral infusion of MPTP are similar to those observed during the early phase of PD, when a moderate loss of nigral dopamine neurons (40-70%) results in sensory and memory deficits with no major motor impairments. These animals also model the working memory and habit learning defi cits, with long-term spatial (episodic) memories being mostly spared as observed in non-demented PD patients. The intranigral infusion of MPTP in rats has led to the development of useful models, which do not present gross motor impairments that would otherwise compromise the interpretation of the performance of the animals in cognitive tasks.

Keywords


Parkinson’s disease; learning; memory; cognition; MPTP; rats; animal model

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DOI: http://dx.doi.org/10.5514/rmac.v32.i2.23276


Editor in Chief:

Dr. Carlos J. Flores-Aguirre

editor_general@rmac-mx.org

ISSN: 0185-4534

ISSN Electrónico: 2007-0802