Artificial gravity during a spaceflight analog alters brain sensory connectivity

Area of Science:

• Neuroscience
• Space Physiology
• Human Physiology

Background:

• Spaceflight induces physiological deconditioning, impacting brain function.
• Artificial gravity (AG) is explored as a countermeasure to spaceflight-induced changes.
• Head-down tilt bed rest (HDBR) simulates microgravity effects on human physiology.

Purpose of the Study:

• To investigate if artificial gravity (AG) modifies resting-state brain functional connectivity during head-down tilt bed rest (HDBR).
• To examine the association between AG, brain connectivity, and changes in balance and mobility.
• To determine if continuous (cAG) or intermittent (iAG) artificial gravity has differential effects.

Main Methods:

• Sixty-day HDBR study with three groups: control (no AG), continuous AG (cAG), and intermittent AG (iAG).
• Resting-state functional connectivity assessed before, during, and after HDBR.
• Balance and mobility measured pre- and post-HDBR.

Main Results:

• Differential functional connectivity changes were observed between the posterior parietal cortex and somatosensory regions, varying by group.
• The control group showed increased connectivity, while the cAG group exhibited decreased connectivity, suggesting AG alters somatosensory reweighting.
• Brain-behavioral correlations differed: increased putamen-somatosensory cortex connectivity correlated with mobility decline in controls but not in the cAG group.

Conclusions:

• Artificial gravity alters brain functional connectivity and somatosensory processing during simulated microgravity.
• AG appears to have a compensatory role, preserving mobility by modulating brain-behavioral relationships.
• Findings support AG as a promising countermeasure against neurophysiological deconditioning in spaceflight and bed rest.