Physiological cerebrospinal fluid interactions between brain and eye structures are altered after long-duration spaceflight

Physiological cerebrospinal fluid interactions between brain and eye structures are altered after long-duration spaceflight Full article

Journal

Experimental Physiology
ISSN: 0958-0670 , E-ISSN: 1469-445X

Output data

Year: 2026, Pages: 1-14 Pages count : 14 DOI: 10.1113/EP093112

Tags

cerebrospinal fluid, long-duration spaceflight, magnetic resonance imaging, periorbital morphology

Authors

Tang Ge ^1,2 , Jillings Steven ³ , Jeurissen Ben ^3,4 , Tomilovskaya Elena ⁵ , Nosikova Inna ⁵ , Ryabova Alexandra ⁵ , Pechenkova Ekaterina ⁶ , Petrovichev Victor ⁷ , Rukavishnikov Ilya ⁵ , Sunaert Stefan ⁸ , Parizel Paul ⁹ , Makovskaya Lyudmila ¹⁰ , Sinitsin Valentin ¹⁰ , Sijbers Jan ⁴ , Annen Jitka ^11,12,13 , Laureys Steven ^12,13 , van Ombergen Angelique ^3,14 , Ahmadi Seyed-Ahmad ² , Wuyts Floris L. ³ , zu Eulenburg Peter ^1,2

Affiliations

1	Institute for Neuroradiology, University Hospital, LMUMunich, Munich, Germany
2	Graduate School of Systemic Neurosciences, LMUMunich, Munich, Germany
3	Lab for Equilibrium Investigations and Aerospace, University of Antwerp, Antwerp, Belgium
4	Imec/Vision Lab, University of Antwerp, Antwerp, Belgium
5	SSC RF – Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
6	Laboratory for Cognitive Research, HSE University,Moscow, Russia
7	Radiology Department, Federal Centre of Treatment and Rehabilitation, Moscow, Russia
8	Translational MRI, Department of Imaging & Pathology, KU Leuven, Leuven, Belgium
9	Radiology Department, Antwerp University Hospital & University of Antwerp, Antwerp, Belgium
10	Faculty of FundamentalMedicine, Lomonosov Moscow State University,Moscow, Russia
11	Faculty of Psychology and Educational Sciences, Department of Data Analysis, Ghent University, Ghent, Belgium
12	Coma Science Group, GIGA-Consciousness, University of Liège, Liège, Belgium
13	Centre du Cerveau, University Hospital of Liège, Liège, Belgium
14	Department of Translational Neurosciences – ENT, University of Antwerp, Antwerp, Belgium

Long-duration spaceflight represents an extreme challenge, triggering adaptive responses including spaceflight-associated neuro-ocular syndrome, characterized by diminished visual acuity and ocular changes, which is a significant health risk for Mars missions. Concurrently, spacefarers experience brain adaptations, including ventricular expansion and CSF redistribution; however, the integrative physiological mechanisms linking these brain–eye responses remain unestablished. We applied automated morphometric analysis to investigate brain–eye relationships using highresolution MRI data from terrestrial control subjects and spacefarers, conducting correlation analysis between third ventricle volume and ocular parameters. Analysis revealed significant baseline correlations between third ventricle volume and multiple ocular parameters in healthy control subjects, including globe dimensions, optic nerve sheath volume, optic nerve length and retro-orbital width. Following spaceflight, adaptations occurred: optic nerve sheath volume increased by 11.93 ± 6.07 mm3 (right) and 27.22 ± 8.74 mm3 (left), and optic nerves lengthened by 0.38 mm (right) and 0.47 mm (left). The baseline analysis showed that multiple orbital structures were correlated with third ventricle volume, whereas longitudinal change analysis revealed selective associations: only globe changes were correlated with third ventricle expansion. This study demonstrates structure-specific brain–eye relationships consistent with CSF-mediated coupling as a mechanism underlying spaceflightassociated neuro-ocular syndrome during the cranialmicrogravity response. Following spaceflight, third ventricle expansion is correlated selectively with globe changes, while dissociating from optic nerve sheath and retro-orbital adaptations, providing quantitative evidence that microgravity creates differential biomechanical effects across orbital compartments. This supports CSF compartmentalization and the limited intracranial volume expansion (cranial ceiling effect) as underlying mechanisms. The findings illuminate the limits of brain elastic tissue expansion during intracranial fluid accumulation in astronauts.

Tang G. , Jillings S. , Jeurissen B. , Tomilovskaya E. , Nosikova I. , Ryabova A. , Pechenkova E. , Petrovichev V. , Rukavishnikov I. , Sunaert S. , Parizel P. , Makovskaya L. , Sinitsin V. , Sijbers J. , Annen J. , Laureys S. , van Ombergen A. , Ahmadi S-A. , Wuyts F.L. , zu Eulenburg P.
Physiological cerebrospinal fluid interactions between brain and eye structures are altered after long-duration spaceflight
Experimental Physiology. 2026. С.1-14. DOI: 10.1113/EP093112 OpenAlex

Submitted:	Sep 9, 2025
Accepted:	Dec 17, 2025
Published online:	Jan 16, 2026

OpenAlex:

W7124442813

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