Microgravity alters vestibular signaling and reduces body loading, driving sensory reweighting. The unloading effects can be modelled using head-down tilt bedrest (HDT). Artificial gravity (AG) has been hypothesized to serve as an integrated countermeasure for the declines associated with HDT and spaceflight. Here, we examined the efficacy of 30 min of daily AG to counteract brain and behavior changes from 60 days of HDT. Two groups received 30 min of AG delivered via short-arm centrifuge daily (n = 8 per condition), either in one continuous bout, or in 6 bouts of 5 min. To improve statistical power, we combined these groups (AG; n = 16). Another group served as controls in HDT with no AG (CTRL; n = 8). We examined how HDT and AG affect vestibular processing by collecting fMRI scans during vestibular stimulation. We collected these data prior to, during, and post-HDT. We assessed brain activation initially in 12 regions of interest (ROIs) and then conducted an exploratory whole brain analysis. The AG group showed no changes in activation during vestibular stimulation in a cerebellar ROI, whereas the CTRL group showed decreased activation specific to HDT. Those that received AG and showed little pre- to post-HDT changes in left vestibular cortex activation had better post-HDT balance performance. Whole brain analyses identified increased pre- to during-HDT activation in CTRLs in the right precentral gyrus and right inferior frontal gyrus, whereas AG maintained pre-HDT activation levels. These results indicate that AG could mitigate activation changes in vestibular processing that is associated with better balance performance.

微重力改变前庭信号并减少身体负荷，从而推动感觉重新加权。卸载效应可以使用头朝下倾斜卧床 (HDT) 进行建模。人工重力 (AG) 被认为可以作为 HDT 和航天相关衰退的综合对策。在这里，我们检查了每天 30 分钟的 AG 对抗 60 天 HDT 后大脑和行为变化的功效。两组每天通过短臂离心机接受 30 分钟的 AG（每种情况n  = 8），连续一轮或 6 轮，每次 5 分钟。为了提高统计功效，我们将这些组合并起来（AG；n  = 16）。另一组作为没有 AG 的 HDT 对照（CTRL；n  = 8）。我们通过在前庭刺激期间收集功能磁共振成像扫描来研究 HDT 和 AG 如何影响前庭处理。我们在 HDT 之前、期间和之后收集了这些数据。我们首先评估了 12 个感兴趣区域 (ROI) 的大脑激活情况，然后进行了探索性全脑分析。AG 组在小脑 ROI 的前庭刺激期间没有显示激活变化，而 CTRL 组则显示 HDT 特异性激活减少。那些接受 AG 且 HDT 前后左前庭皮层激活几乎没有变化的人在 HDT 后平衡表现更好。全脑分析发现，右侧中央前回和右额下回的 CTRL 在 HDT 前至 HDT 期间激活增加，而 AG 维持 HDT 前激活水平。这些结果表明，AG 可以减轻与更好的平衡性能相关的前庭处理的激活变化。