Microgravity-induced cerebral neuroplasticity: a systematic review of structural and functional brain adaptations

Abstract

Prolonged exposure to microgravity constitutes a unique physiological challenge to the human body and represents a critical issue for long-duration space missions, particularly due to its potential effects on the central nervous system. Over recent decades, scientific evidence has demonstrated that microgravity induces significant alterations in brain structure and function; however, these findings remain fragmented across heterogeneous experimental models and methodological approaches, limiting an integrated understanding of cerebral adaptation. The objective of this study was to systematically synthesize and critically analyze PubMed-indexed evidence on cerebral neuroplasticity induced by microgravity.

A systematic review of the literature was conducted in accordance with PRISMA guidelines. The search was performed exclusively in the PubMed database and included studies published between 2015 and 2025. Eligible studies comprised investigations involving human spaceflight, validated ground-based microgravity analogs, and experimental animal models, provided that they assessed structural or functional cerebral outcomes using neuroimaging or neurophysiological techniques.

The results revealed consistent cerebral adaptations across different models, including cephalad cerebrospinal fluid redistribution, ventricular expansion, regionally specific gray matter reorganization, white matter microstructural alterations (particularly in cerebellar and sensorimotor pathways) and functional connectivity changes involving vestibular, visual, and motor networks. These findings indicate that cerebral adaptations result from the interaction between mechanical fluid shifts and experience-dependent sensory reweighting.

In conclusion, microgravity induces robust and multidimensional cerebral neuroplastic responses, encompassing both adaptive and potentially maladaptive processes. Understanding these mechanisms is essential for astronaut neurological health, the development of effective countermeasures, and the advancement of knowledge on human brain plasticity under extreme environmental conditions.