Sex Differences in Neurophysiological Changes Following Voluntary Exercise in Adolescent Rats
Lindsay Ferguson1,2, Christopher C. Giza1,2, Rebecka O. Serpa1,2, Tiffany Greco1,2, Hannah Roberts3, Michael Folkerts3, Mayumi L. Prins1,2.
1UCLA, David Geffen School of Medicine, Department of Neurosurgery, Brain Injury Research Center, Los Angeles, CA; 2UCLA, Steve Tisch BrainSPORT Program, Los Angeles, CA; 3Pepperdine University, Seaver College, Department of Psychology, Malibu, CA
BACKGROUND: Adolescence is a period of time characterized by the onset of puberty and is marked by gross physical changes that can play a role in athletic performance in addition to cognitive and social developments. Sex differences are present with differences in body size, height, physiology and behavior which contribute to differences in athletic performance. Pre-clinical studies representing this active group are lacking. METHODS: Male and female adolescent rats were given chronic voluntary access to a running wheel and activity was recorded for 10 days. Running behavior was analyzed daily. Estrous cycle was also monitored daily for females. A second group was given 10 day voluntary access to running wheel, then rested for 10 days to determine the long-term effects of exercise on the adolescent brain. Brain and muscle tissue was harvested at day 10 and 20 to understand exercise-dependent changes in mitochondrial activity and neuroplasticity. Animal cohorts were carried out at 2 different sites: University of California Los Angeles and Pepperdine University. RESULTS: On average, running distance, intensity of run, and length of running bout increased for both males and females across the 10 days measured. Females ran significantly further and at longer intervals compared to males. Cortical and muscle expression of PGC1α showed similar levels at 10 days regardless of sex and exercise. There was a significant increase in expression at 20 days in all groups (p’s<0.05). Cortical and hippocampal levels of BDNF were similar across all groups, however, BDNF was significantly higher in exercised males and females at both the 10 day and 20 day time point. DISCUSSION: Adolescent rats given chronic access to exercise show changes in physiologic function. There are sex differences in running behavior not impacted by sex hormones. These results are important to further our understanding of exercise on the adolescent brain.
Breakout Room: Ferguson, Lindsay
View Poster: https://uclacns.org/symposium2021/5-Ferguson-Lindsay.pdf