Effect of chronic intranasal administration of α-synuclein oligomers on motor activity and anxiety in adult and middle-aged mice
Among the least experimentally studied aspects of the pathogenesis of α- synucleinopathies (major representatives, Parkinson`s disease and Lewy body dementia) are age-related effects of amyloidogenic α-synuclein species resulting from overexpression and misfolding on mammalian behavior and physiological functions. The aim of this study was to evaluate effects of α-synuclein oligomers on motor behavior and anxiety in adult and middle-aged mice. Methods. Experiments were performed on 6- and 12-month-old male C57Bl/6 mice. A solution of α-synuclein oligomers or saline was administered once a day for 14 days (total dose, 0.48 mg/kg). To evaluate the overall motor activity and anxiety, the open field and elevated plus maze tests were used. Results. Chronic administration of α-synuclein oligomers to adult mice increased anxiety without overall motor disorders while middle-aged mice demonstrated both changes in their motor activity (decreases in average speed and path length) and increased anxiety. Conclusions. The study showed that the behavioral effects of α-synuclein oligomers administered chronically, intranasally were age-dependent.