Avaliação de sintomas motores e não motores em um modelo de parkisonismo experimental induzido por rotenona em ratos

Abstract

Parkinson's disease (PD) affects about 1.6% of the world's population over 65 years old, being the second most common neurodegenerative disease in the elderly. PD is characterized by the progressive loss of dopaminergic neurons of the substantia nigra, leading to a severe reduction of dopamine levels, resulting in several motor symptoms (resting tremor, bradykinesia, instability, postural abnormalities and akinesia) and non-motor symptoms (anosmia, depression, dementia, anxiety, gastrointestinal problems etc.). Wistar rats (220-250g) were divided into two groups: ROT (receiving rotenone 2.75mg / kg, i.p. for 21 days) and CTL (receiving the DMSO vehicle + sunflower oil i.p for 21 days). The results showed that rotenone was able to induce motor deficits after 14 and 21 days of administration in the horizontal and vertical exploration and mean velocity of the animals in the open field test, as well as in the postural stability in the modified cylinder test, also observed losses in motor coordination in the rotarod test. The deficit observed after 21 days in rotarod was responsive to apomorphine, which improved the performance of the animals. Rotenone also induced non-motor deficits such as olfactory impairment in the pellet test buried after 7 and 21, as well as in the olfactory discrimination test after 21, type-depressive behavior in the sucrose preference test after 14 and 21 days, as well as in working memory in the Y-maze test and aversive memory in the passive avoidance test after the 21st day. Rotenone also married decreased gastric emptying and intestinal motility in the red phenol test after day 21, as well as induced loss of dopamine and DOPAC content in the striatum. The results obtained in the present study suggest that rotenone can induce several motor deficits after and not motor after 14 and 21 days of administration, as well as a reduction of the striatal dopamine content, and it may be a good model of parkinsonism that can be used in the search for new neuroprotective substances as well as the understanding of the pathogenesis of this disease.