Unipd studies the effects of space travel
28.01.2025
The new study "Short-term suborbital space flight curtails astronauts’ dopamine levels increasing cortisol/BDNF and prompting pro-oxidative/inflammatory milieu" led by Gerardo Bosco of the Department of Biomedical Sciences at the University of Padua and Mrakic-Sposta from the CNR in Milan, conducted on three Italian aviation pilots who for the first time undertook a commercial suborbital flight known as Galaxy 01, sheds new light on significant biological parameter changes that astronauts can experience during or, more precisely, upon returning to Earth.
Using highly innovative and user-friendly techniques such as collecting a saliva sample with a small salivette, Bosco, Mrakic-Sposta, and colleagues demonstrated that even a relatively short stay in space (like the approximately 60 minutes of the Galaxy 01 mission) is sufficient, once back on Earth, to alter levels of essential molecules for stress response control or cognitive abilities.
Indeed, space travel is no longer a privilege reserved for professional astronauts. This spread of "space flight" today raises new important questions, namely what the biological responses in the bodies of space travelers might be, whether they are well-trained or, especially, last-minute astronauts.
"We recorded a sharp decline in circulating dopamine levels, which is involved in the control of voluntary movement and emotional responses, accompanied by an increase in brain-derived neurotrophic factor (BDNF), a protein that governs the control of the development, maintenance, and functioning of nerve cells, especially under stress conditions, and communication between nerve cells themselves," explains Gerardo Bosco. "These alterations suggest an initial stress response. In fact, these alterations were also accompanied by a significant increase in cortisol levels, a hormone typically released in all conditions characterized by fatigue, tension, and physical and/or mental strain."
"This study also reveals that suborbital flight induces a decrease in factors that normally prevent the rise of circulating and tissue levels of oxygen free radicals, thereby establishing conditions that, over time, could lead to generalized oxidative stress," adds Simona Mrakic-Sposta. "We also discovered an increase in specific molecules involved in the initiation and propagation of the inflammatory response."
The authors emphasize that, although this is a pilot study conducted on only three astronauts (all male and of similar age), it is one of the first efforts to better characterize the possible risk factors associated with space missions, especially if prolonged or repeated in short periods, and not least, if the individuals launched into space have not received adequate and sufficient training.
The study was published in the journal "Military Medical Research," which aims not only to cover basic and clinical research aspects concerning modern military medicine but also basic and clinical medical research with translational potential related to the exposure of men and women to extreme environmental conditions - whether military or not - that can lead to various forms of stress, including post-traumatic stress.
"It is our hope," conclude the authors, "that our data obtained in a relatively short time window (72 minutes between preparation, flight, and landing) and showing an incipient state of oxidative and inflammatory stress, can guide future studies conducted on subjects involved in longer or repeated space missions. These prospective studies could highlight in more detail what the brain and peripheral repercussions of exposure to microgravity and other physical changes due to space travel might be, focusing on the possible onset of both acute and chronic diseases."
The study also involved contributions from Tommaso Antonio Giacon (Unipd), Professor Vezzoli (CNR of Pisa), and Professor Paolocci (Unipd and Johns Hopkins of Baltimore).
