Cerebellum-dependent motor and cognitive abilities are reduced in an aging rat model

CASTRO PASCUAL, IVANNA CARLA; ALTAMIRANO, FERNANDO GABRIEL; FERRAMOLA, MARIANA LUCILA; LACOSTE, MARÍA GABRIELA; MARTÍN, MAURICIO; DELGADO, SILVIA MARCELA; ANZULOVICH, ANA CECILIA

San Luis

Congreso; XXXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2019

Sociedad de Biología de Cuyo

As we age, movements become slower and inconsistent and require more attention. The ability to control movement is crucial. Therefore, in order to succeed in promoting longer functional independence, we need to understand the normal aging process of motion control. Such aging engine is obviously multifactorial and complex. However, one of the specific structures that may have a predominant role in understanding this process is the cerebellum. Previously, we observed Bdnf expression oscillates on a circadian basis in the young rat cerebellum. Interestingly, aging reduces the rhythm?s amplitude and phase shifts its acrophase. Here, we examine the evidence supporting the hypothesis that motor aging causes alterations in functions such as motor coordination, motor learning and balance, at the time when locomotor activity starts in nocturnal rats, and following the maximal expression of Bdnf. We evaluated these parameters through the Single Reaching Pellet (SRP) which determines performance in motor coordination and motor learning, and Beam Walking (BW) Tests, which establishes the performance in balance. The tests were performed by young (3 month-old, n = 11), and old (22 month-old, n = 5), Holtzman rats maintained under 12h light:12h dark and constant T° conditions as well as fed with a regular chow diet and water ad-libitum. The statistical tests used in this study were t-Test in the case of the behavioral tests and oneway ANOVA followed by Tukey pos hoc test, ChronosFit and Cosinor, in the case of Bdnf expression. We observed that the percentage of total success rate and the quality of the first attempt during the performance are significantly lower in old rats compared to young rats (p = 0.01) in SRP. Better performance of cognitive and behavioral tests performed by and observed in young animals at the endof-the-day-beginning-of-the-night, follows the maximal expression of the neurotrophic factor, Bdnf1 at CT 05:39 ± 00:09. In the case of the BW test, we observed that the old rats presented a higher number of foot slip, as well as falls, than the young group (p