Research Paper Volume 11, Issue 2 pp 371—385
Age-related alterations in the modulation of intracortical inhibition during stopping of actions
- 1 KU Leuven, Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Biomedical Sciences, Leuven, Belgium
- 2 KU Leuven, Leuven Brain Institute (LBI), Leuven, Belgium
Received: November 7, 2018 Accepted: December 19, 2018 Published: January 22, 2019https://doi.org/10.18632/aging.101741
How to Cite
Copyright: Hermans et al. This is an open‐access article distributed under the terms of the Creative Commons Attribution License (CC BY 3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
We investigated the effect of age on the ability to modulate GABAA-ergic and GABAB-ergic inhibitory activity during stopping of action (reactive inhibition) and preparation to stop (proactive inhibition). Twenty-five young and twenty-nine older adults performed an anticipated response version of the stop-signal task with varying levels of stop-signal probability. Paired-pulse transcranial magnetic stimulation was applied to left primary motor cortex to assess the modulation of GABAA-mediated short-interval intracortical inhibition (SICI) during stopping and GABAB-mediated long-interval intracortical inhibition (LICI) during the anticipation of a stop-signal. At the behavioral level, reactive inhibition was affected by aging as indicated by longer stop-signal reaction times in older compared to young adults. In contrast, proactive inhibition was preserved at older age as both groups slowed down their go response to a similar degree with increasing stop-signal probability. At the neural level, the amount of SICI was higher in successful stop relative to go trials in young but not in older adults. LICI at the start of the trial was modulated as a function of stop-signal probability in both young and older adults. Our results suggest that specifically the recruitment of GABAA-mediated intracortical inhibition during stopping of action is affected by aging.
CS: conditioning stimulus; CSE: corticospinal excitability; EMG: electromyography; FDI: first dorsal interosseous; GABA: gamma-aminobutyric acid; GoRT: go response time; ISI: inter stimulus interval; LICI: long-interval intracortical inhibition; M1: primary motor cortex; MEP: motor evoked potential; MSO: maximum stimulator output; SICI: short-interval intracortical inhibition; SSP: stop-signal probability; SSRT: stop-signal reaction time; ST: stop time; TMS: transcranial magnetic stimulation; tMT: task motor threshold; TS: test stimulus.