DIFFERNTIAL DOPAMINE RESPONSES DURING AUDITORY-MOTOR SYNCHRONIZATION IN YOUNG AND OLDER HEALTHY ADULTS

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Yuko Koshimori^1,2 (yuko.koshimori@utoronto.ca), Antonio Strafella^2,3,4, Vivek Sharma¹, Pablo M Rusjan⁵, Sylvain Houle², Michael H Thaut¹; ¹University of Toronto, ²Centre for Addition and Mental Health, ³Toronto Western Hospital, ⁴Krembil Research Institute, ⁵McGill University

We demonstrated that external rhythmic auditory cueing using metronome clicks and rhythmic beats in music improved finger tapping performance and modulated dopamine (DA) responses in the left ventral striatum (VS) in young healthy adults.1 The current study is extended to investigate if the dopamine responses in basal ganglia (BA) are different between young and older healthy adults. Twelve right-handed participants aged between 18 and 35 were included in this study. Each participant underwent two [11C]-(+)-PHNO-PET scans: during one scan, finger tapping with rhythmic auditory stimulation (RAS; RAS condition) and the other scan, the same finger tapping task without RAS (No-RAS condition). Binding potential relative to the non-displaceable compartment (BPND) values were used as outcome measures for DA responses. BPND changes between conditions in the BG were compared between the two groups. In both groups, RAS reduced the absolute tapping period error and significantly reduced tapping variability (both groups combined: p=.01 and p=.001, respectively). The BPND changes in the right putamen showed a significant group difference (p=0.028). Older participants exhibited 13% increase in DA response while young participants exhibited a 4% decrease in DA response in the ROI during the finger tapping with RAS. Our preliminary data have shown that rhythmic auditory cueing may have differential effects on DA responses in young and older adults: reduced DA responses in young adults vs increased DA responses in older adults. Further investigation will need to confirm the preliminary findings. 1.Koshimori et al (2016). Front. Neurosci

Topic Area: PERCEPTION & ACTION: Motor control