Medicamentul Veterinar (Jun 2017)
PAIN IN A PARKINSON`S DISEASE RODENT ANIMAL MODEL INDUCED WITH 6-HYDROXYDOPAMINE
Abstract
Pain phenomenon, the unpleasant sensory and emotional event, appears to evidently intrude in Parkinson disease (PD), a disease formally considered to be restricted only to motor deficits. Although over a half of persons with PD suffer from pain manifestations, there are very few reports targeting this issue. Considering the cases when motor symptoms of PD are eclipsed by severe pain disclosure, there is an obvious need of clarifying the intricate implications of pain in PD context. Because there are few studies researching the link between pain and PD in clinical context, but as well in animal models we chose to explore the effects of pain stimuli on a rodent model of PD. Materials and methods: We experimentally induced a PD model in Wistar rats (n=12) by injecting in the substantia nigra, a brain area known to be involved in PD occurrence, one dose of a 6-hydroxidopamine (6-OHDA) solution (8µm 6-OHDA base and 4µm physiological saline), utilizing neurosurgery, while their control peers received same dose of saline solution. Two weeks after the intervention the animals were subjected to the hot-plate test, a behavioral task for acquiring pain sensitivity. Results: There was noticed a statistical significant (F(1,10) = 5.67, p=0.038) sensibility of the 6-OHDA rats to thermal pain stimuli (8.2 s ± 0.8 s in 6-OHDA group) as compared to their peers (13.8 s ± 1.6 s in controls). Conclusions: The involvement of pain in PD animal models is demonstrated raising questions of how it influences PD evolution. Moreover, this result increases awareness of deficient diagnostic methods of pain in PD and as a consequence, poor treatment of pain manifestations.
