Significant leg RC slope decreases were observed on post-bed rest day 1 (P1) (t(2805) = -4.14, P < 0.0001), P2 (t(2805) = -6.59, P < 0.0001), P3 (t(2805) = -6.15, P < 0.0001), P5 (t(2805) = -7.93, P <0.0001), P8 (t(2805) = -3.30, P = 0.001), and P12 (t(2805)= -3.33, P = 0.0009), suggesting a group decrease in corticospinal excitability in the immediate post-bed rest period with recovery approaching baseline over the following 2 wk. Significant effects were observed for hand RC slopes only for P2 (t(2916) = 1.97, P = 0.049), P3 (t(2916) = -2.12, P = 0.034), and P12 (t(2916) = -2.19, P = 0.029); no significant effects were observed for days P0 (t(2916) = -1.32, ns), P1 (t(2916) = 1.00, ns), P5 (t(2916) = -0.21, ns), or P8 (t(2916) = -0.27, ns). fMRI showed no change in activation for the hand but an increase in activation post-bed rest for the leg. On an individual basis, a more heterogeneous response was found which showed a potential association with performance on FMT.
Results of this research include a better understanding of the cortical plasticity associated with leg disuse and may lead to applications in patient and astronaut rehabilitation.
|Mission||Launch/Start Date||Landing/End Date||Duration|
|Campaign 3||02/20/2005||04/14/2010||5 years, 1 month, 25 days|