Texas Children’s Hospital and Baylor College of Medicine send human brain organoids to the International Space Station

The researchers will study the effects of cosmic radiation and microgravity on how new neurons form in our brains, with the ultimate goal of identifying potential new treatments for brain diseases and cancer 

Thirty brain organoid samples generated in the laboratory of Dr. Mirjana Maletic-Savatic, associate professor of Baylor College of Medicine and principal investigator at the Jan and Dan Duncan Neurological Research Institute (Duncan NRI) at Texas Children’s Hospital, were launched from the Kennedy Space Center in Florida aboard the Space X (SPX-30) rocket to the International Space Station National Laboratory on March 21, 2024. After spending a month in space, the brain organoids returned to the lab yesterday in good condition. 

The launch offered Dr. Maletic-Savatic and her team at the Duncan NRI an unprecedented opportunity to gain novel insight into how cosmic radiation and microgravity in space affect neurogenesis - the process by which new neurons are formed in the brain throughout our life - and whose disruptions result in a multitude of neurological and neurodegenerative diseases. 

These studies will provide insight into the pathogenesis of many neurological and neurodegenerative disorders and a path forward to new therapeutic strategies.

The brain organoids are tiny three-dimensional structures that mimic human brains and can form new neurons. They were derived from the skin cells of healthy individuals, and induced to become brain organoids (aka ‘mini-brains’). Unlike traditional two-dimensional cell cultures that adhere to and grow on inert flat surfaces, organoids provide a more physiologically relevant model that closely resembles the structural, cellular, and biochemical complexity of human organs. They, therefore, provide a versatile platform for studying a wide range of conditions affecting human brain development. 

“Replicating cosmic radiation and microgravity on Earth is exceptionally challenging,” said Dr. Mirjana Maletic-Savatic, who is a Cynthia and Anthony G. Petrello Endowed Scholar in Neurological Research at Texas Children's Hospital. “We are hopeful this unique opportunity to expose brain organoids we’ve generated to space conditions will help bridge that gap in knowledge and offer us a realistic picture of how cosmic radiation and microgravity influence the formation and survival of new neurons and nearby support cells.”

In the coming months, the team will conduct extensive metabolic and functional analyses on these organoids to evaluate the effects of microgravity and space radiation on their growth, survival, and function.

“We also hope to uncover potential protective effects of drugs custom-made by Dr. Damian Young and his team at the Center for Drug Discovery here at the Duncan NRI in mitigating damage due to such exposures,” Dr. Maletic-Savatic added. ”These findings stand to benefit not only space biology research but also advance our understanding of the effects of radiation on cancer patients and provide improved therapeutic models to study neurodegenerative conditions such as Alzheimer’s.” 

The human brain has a remarkable capacity to generate new neurons throughout life. These newborn neurons, originating from neural stem cells, play a critical role in forming neural circuits and are essential for learning, memory, and mood control. This process, however, is highly susceptible to environmental influences and a decline in the formation of new neurons has been linked to cognitive impairment and depression. 

Notably, exposure to factors such as radiation substantially depletes neural stem cells, accelerating deficits in learning and changes in mood. This aspect holds particular significance for cancer patients undergoing radiation therapy and for those participating in space exploration by NASA and private companies.

As humanity plans to increase interplanetary travel, understanding the impacts of space radiation, microgravity, and chronic stress on the health of astronauts is increasingly becoming a focal point of space biology research. Understanding how potential impairment of neurogenesis in astronauts could have profound effects on their cognitive and mental well-being during extended missions, such as those to the moon and Mars, and finding ways to mitigate that damage, could prove critical in planning and implementing such missions.