Bilateral lesions of the nigrostriatal pathways are associated with chronic mechanical pain hypersensitivity in rats

Some patients with Parkinson's disease (PD) suffer from pain before motor symptoms. To model this, we proposed to assess the mechanical hypersensitivity in an animal model of PD with a bilateral lesion of the nigrostriatal pathway. PD model was validated by a decrease of locomotor activity and a 76% dopamine cell loss in the substantia nigra pars compacta. PD animals displayed a decrease of mechanical thresholds, correlated with the degree of the dopamine lesion. This animal model displays nociceptive disorders as found in PD patients and could be useful to assess the effects of new antiparkinsonian drugs. (C) 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.