Space flight and central nervous system: Friends or enemies? Challenges and opportunities for neuroscience and neuro‐oncology

Abstract

Space environment provides many challenges to pilots, astronauts, and space scientists, which are constantly subjected to unique conditions, including microgravity, radiations, hypoxic condition, absence of the day and night cycle, etc. These stressful stimuli have the potential to affect many human physiological systems, triggering physical and biological adaptive changes to re-establish the homeostatic state. A particular concern regards the risks for the effects of spaceflight on the central nervous system (CNS), as several lines of evidence reported a great impact on neuroplasticity, cognitive functions, neurovestibular system, short-term memory, cephalic fluid shift, reduction in motor function, and psychological disturbances, especially during longterm missions. Aside these potential detrimental effects, the other side of the coin reflects the potential benefit of applicating space-related conditions on Earth-based life sciences, as cancer research. Here, we focused on examining the effect of real and simulated microgravity on CNS functions, both in humans and in cellular models, browsing the different techniques to experience or mime microgravity on-ground.Increasing evidence demonstrate that cancer cells, and brain cancer cells in particular, are negatively affected by microgravity, in terms of alteration in cell morphology, proliferation, invasion, migration, and apoptosis, representing an advancing novel side of space-based investigations. Overall, deeper understandings about the mechanisms by which space environment influences CNS and tumor biology may be promisingly translated into many clinical fields, ranging from aerospace medicine to neuroscience and oncology, representing an enormous pool of knowledge for the implementation of countermeasures and therapeutic applications.

Trolox and recombinant Irisin as a potential strategy to prevent neuronal damage induced by random positioning machine exposure in differentiated HT22 cells

“…Interestingly, a close association between the space environment exposure and alterations in the expression of proteins involved in neuronal structure and metabolic function was also recently observed by Mao et al who characterized proteomic changes in the brains of mice upon return from a 13-day Space Shuttle Atlantis mission. Proteomic analysis showed alteration of 26 proteins involved in synaptic plasticity in gray and white matter after spaceflight, confirming the impact of the absence of load on brain structure and integrity [ 18 ]. Finally, Chen and colleagues investigated the effects of simulated microgravity for 7 and 21 days on the hippocampus, cerebral cortex, and striatum in a tail suspension rat model, finding reduced expression of brain-derived neurotrophic factor (BDNF), marked oxidative stress and atrophy of neurons in the cerebral cortex after 21 days of exposure.…”

Potential Biomarkers of Resilience to Microgravity Hazards in Astronauts

“…Microgravity exposure during spaceflight can have profound effects on the central nervous system (CNS), leading to a range of potential neurological issues [ 23 , 24 ]. One of the most common CNS disturbances experienced by astronauts is space motion sickness (SMS), which is characterized by symptoms such as nausea, vomiting, headache, and disorientation [ 25 , 26 ].…”

Homo sapiens—A Species Not Designed for Space Flight: Health Risks in Low Earth Orbit and Beyond, Including Potential Risks When Traveling beyond the Geomagnetic Field of Earth

“…Brain changes at the functional [ 76 , 77 , 78 , 79 ] and structural [ 80 ] levels can occur during space flight and when living in LEO conditions for long periods of time. Such changes may be the result of fluid shifts and the response to microgravity [ 81 ]; however, the space environment contains multiple stressors, including radiation, elevated CO 2 levels, psychological stress, sleep deprivation, nutritional issues, and others [ 77 , 82 , 83 , 84 , 85 ] that could contribute to alterations in cognition and neural activities.…”