Programa de Pós-Graduação em Farmacologia

É com grande orgulho que a Coordenação do Programa de Pós-Graduação em Farmacologia (PPGFMC) parabeniza a mestranda do PPGFMC Dayse Machado de Melo pela conquista do Prêmio Nacional Juarez Aranha Ricardo promovido pela Sociedade Brasileira de Neurociências e Comportamento (SBNeC), durante a XLIII Reunião da SBNeC realizada de maneira online de 13 a 17 de outubro de 2020.

O trabalho intitulado “SEX MATTERS: INTRANASAL ADMINSTRATION OF MPTP INDUCES NON-MOTOR SYMPTOMS OF PARKINSON’S DISEASE SELECTIVELY IN C567BL/6 FEMALE MICE” faz parte da sua dissertação de mestrado que está sendo desenvolvida no PPGFMC sob a orientação do professor Rui Daniel Prediger.

Introduction: Parkinson’s disease (PD) is characterized by motor symptoms including resting tremors, bradykinesia and muscular rigidity. However, nowadays is well known that non-motor symptoms, such as olfactory, gastrointestinal, cognitive and emotional impairments, may appear many years before the clinical diagnosis. Interestingly, there is increasing evidence of gender-related differences in PD. For instance, PD incidence and prevalence are higher in men, whereas women with PD manifest more frequently depression, anxiety and constipation.

Objective: The main aim of this study was to investigate putative sex-related differences in the development of non-motor symptoms of PD in male and female C567BL/6 mice submitted to intranasal (i.n.) administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), an animal model of early stages of PD (Curr Pharm Des 17:489, 2011).

Methods: All experiments were previously approved by the CEUA/UFSC (protocol 5097220420). A total of 12 male and 12 female C57BL/6 mice (4-5 months old) received a single bilateral i.n. administration of MPTP (0.5 mg per nostril) or saline and were submitted to a battery of behavioral tasks: olfactory discrimination (day 5), splash test (day 12), fecal output (days 7 and 14), tail suspension and open field tests (day 15). Data from the olfactory discrimination test was analyzed by the Student t test and the rest of data was evaluated using two-way ANOVA followed by multiple post-hoc comparisons using the Newman-Keuls test. The accepted level of significance for the results was p ≤ 0.05.

Results: In the olfactory discrimination test, mice from the control group (regardless of sex) were able to discriminate between familiar and non-familiar compartments, as indicated by higher time spent in the familiar compartment. The i.n. administration of this low MPTP dose induced an early disruption in olfactory discrimination ability selectively in female mice . Moreover, only females infused intranasally with MPTP displayed a significant reduction in the total output of fecal pellets and a significant increase in the immobility time on the tail suspension test. In addition, the i.n. administration of the current MPTP dose did not induce neither motor impairments nor anhedonic-like behaviors in male and female mice.

Conclusion: These findings provide new evidence that female mice are more susceptible than male mice to the development of non-motor symptoms of PD following i.n. MPTP administration, including olfactory and gastrointestinal deficits and depressive-like behaviors.

Financial support: UFSC, CAPES, CNPq and FAPESC.