Microgravity effects on the human brain and behavior: Dysfunction and adaptive plasticity

Area of Science:

• Neuroscience
• Space Medicine
• Human Physiology

Background:

• Space travel poses risks to the human brain and behavior.
• Research shows spaceflight induces both brain dysfunction and adaptive neural changes.
• Existing knowledge highlights effects like fluid shifts and gray matter changes alongside neural compensation.

Purpose of the Study:

• To introduce a new framework, Spaceflight Perturbation Adaptation Coupled with Dysfunction (SPACeD), for understanding spaceflight's brain effects.
• To synthesize current literature on neurobehavioral dysfunction and adaptation in spaceflight and microgravity.
• To explore factors influencing these spaceflight-induced neural changes.

Main Methods:

• Literature review of neurobehavioral effects of spaceflight and microgravity analogues.
• Conceptual framework development (SPACeD).
• Comparative analysis with the aging literature.

Main Results:

• Spaceflight induces co-occurring neurobehavioral dysfunction and adaptive plasticity.
• Adverse effects include intracranial fluid shifts, gray matter changes, and white matter declines.
• Adaptive effects involve sensory reweighting and neural compensation.

Conclusions:

• The SPACeD framework helps synthesize complex brain changes during spaceflight.
• Parallels exist between spaceflight and aging concerning neurobehavioral dysfunction and adaptation.
• Future research should differentiate dysfunctional from adaptive effects and track recovery timelines.