Our Brain in Space...
Prof. K. Ganapathy
InnovaSpace Advisory Board member, Past President Telemedicine Society of India, Former Secretary/Past President Neurological Society of India & Indian Society for Stereotactic & Functional Neurosurgery, Emeritus Professor Tamilnadu Dr MGR Medical University, Former Adjunct Professor IIT Madras & Anna University Madras, Founder Director, Apollo Telemedicine Networking Foundation & Apollo Tele Health.
Three decades ago even contemplating the subject of the human brain in space would have been considered preposterous. Two decades hence and Extra Terrestrial Neurosciences could become a distinct sub-speciality. With periods of stay in the International Space Station steadily increasing, manned missions to the Moon being revived, and even humans going to Mars being seriously planned, it is imperative we know what happens structurally and functionally to various parts of the human brain when it is exposed to microgravity and cosmic radiation for prolonged periods. This is no longer a theoretical academic discussion. For decades we have relied on experimental simulation studies on the brains of rats exposed to microgravity and cosmic radiation. Mice exposed for six months to the radiation levels prevalent in interplanetary space exhibited serious memory and learning impairments, also becoming more anxious and fearful. Structural changes at a microscopic level, including changes in neurotransmitters were demonstrated.
It is only in the last decade that reliable, prospective clinical and sophisticated imaging studies have been carried out on astronaut brains before and after exposure to real world conditions. The human brain was primarily designed for standing in gravity on Earth with almost no exposure to radiation. When we leave the Earth’s gravitational pull all bodily fluids move upward. The first evidence for structural changes in the brain after long-term spaceflight includes narrowing of the central sulcus, a shrinking of the cerebrospinal fluid (CSF) spaces at the vertex, and an upward shift of the brain. MRI scans before spaceflight, shortly after and several months after return to Earth revealed a significant increase in size of the lateral and third ventricles immediately post-flight and a trend towards normalization at follow-up. There was an upward shift of the brain after all long-duration flights. Significant volumetric gray matter decreases, including large areas in the temporal and frontal poles and around the orbits have been documented. This effect was more noticeable in crewmembers with prolonged stay in the International Space Station. Bilateral focal gray matter increases within the medial primary somatosensory and motor cortex (cerebral areas representing lower limbs) were noted. Cortical reorganization in an astronaut’s brain after long-duration spaceflight has now been confirmed.
MRI documented structural changes raise the risk of possible impairment of behaviour, cognition and performance. This could compromise mission critical decisions. In 2017, a study revealed that long missions in space results in reduction of protective CSF surrounding brain volume at the top of astronauts’ brains. These changes underlie the astronauts’ performance on certain critical tasks, such as opening the space station’s hatch, climbing a ladder, exiting a vehicle or even walking along the surface of a planet. Follow up MRI scans have revealed that re-exposure to Earth’s gravity and lack of continuing exposure to unnatural radiation can generally reverse these space travel induced changes. Astronauts have to undergo extensive training before and during spaceflight to maintain muscle mass, and this can result in localised increased grey matter, particularly in the sensorimotor regions of the brain, representing the lower limbs. This is due to neuroplasticity or adaptation within the cerebrum and cerebellum.
The most notable findings in the MRI’s were a post-flight increase in the stimulation-specific connectivity of the right posterior supra marginal gyrus with the rest of the brain; a strengthening of connections between the left and right insulae, decreased connectivity of the vestibular nuclei, right inferior parietal cortex and cerebellum with areas associated with motor, visual, vestibular, and proprioception functions. Study of permanent visual acuity impairments associated with spaceflight have demonstrated structural changes in the CSF around the optic nerves and the globe of the eyes.
Domain expertise in Extra Terrestrial Neurosciences will eventually be a reality. While the number of subjects studied may at the best be a few hundreds, the lessons learnt could make us relook at the traditional neurosciences we have been believing in for the last two centuries.
Let us never forget that the future is always ahead of schedule !!
Learning From Disability...
Nelson A. Campos Vinagre
Commercial pilot / Professor of Sports Science
Sporting activities for athletes with disability have existed for more than a 100 years. Relevant contributions to this area of knowledge occurred in the 18th and 19th centuries that demonstrated the importance of sports participation in the rehabilitation and re-education process of people with special needs. Cutting-edge research has targeted methods that can reduce the consequences of living with reduced mobility and, at the same time, provide new ideas and possibilities for engaging in sporting activities as a means of treatment and rehabilitation. This has led in recent decades to greater opportunities for people with disabilities to participate in sports, and the prospect of further moves for inclusion in the coming years should continue to help improve their quality of life.
The mobility provided by assistive technologies is known to contribute positively to the medical and psychological needs and treatment of casualties of armed conflict and has provided them with opportunities to overcome the life-changing injuries they have endured, both the physical and mental challenges. The Invictus Games, championed by Prince Harry, Duke of Sussex, which first took place in London UK in 2014, is an excellent example of how the power of sporting inclusion can inspire wounded and sick service personnel in their rehabilitation, providing an arena to not only motivate them in their personal journeys to recovery but also to generate a wider understanding and respect from the general public for those who serve their country.
Use it or lose it in Space Missions...
MSc Space Physiology & Health; Human Performance Intern, McLaren Applied Technologies
With international space agencies and the real-life Tony Stark (Elon Musk) making huge advances in rocket technology, it is likely that within the next couple of decades humankind will touch down on Mars. However, this is only half the battle. The gravity on Mars is roughly one third as strong as Earth’s. You may be thinking “great, everything will require less effort”, and you’d be right, however, there is a huge caveat to that. As we’ve found from the results of time spent in space (the longest continuous period being 14.4 months), when people are exposed to levels of gravity lower than that on Earth, losses in muscle and bone occur; predominantly, in muscles which we continually use to walk and maintain our posture. You may have heard the expression ‘use it or lose it’ - hugely applicable here. These losses can increase astronauts’ risk of injury when returning to Earth by leaving them very weak and fragile. A return mission to Mars will take around 3 YEARS to complete, mainly because of the wait for the two planets to be close enough in proximity again to allow a relatively short journey home. That’s around 12 months in microgravity and around 26 months in Martian gravity. Now, it doesn’t take a rocket scientist to figure out that, based on the numbers, the outlook for muscle retention isn’t great. That being said, we‘re still pretty uninformed about the extent to which living on Mars will stimulate our muscles.
Admin Director, InnovaSpace
A really exciting week lies ahead for the Aerospace Medicine and Rehabilitation Laboratory team of researchers from Northumbria University in Newcastle, UK. Led by Professor Nick Caplan, the team will take part in a partial-gravity parabolic flight campaign organised by the European Space Agency, the problem under investigation being one that affects many astronauts when they spend time in the microgravity of space – back pain.
It is well known that astronauts increase in height during their missions, usually between 3-5 cm. While under the influence of the gravity on Earth, the spine is compressed, rather like a spring being pushed down. Remove that force of gravity and the spring will expand and stretch, and this is what is thought to happen in space – the force of gravity is removed and so the vertebrae that make up the spine stretch out, and hence the increase in height and discomfort as connecting ligaments and support muscles extend. Over time spent in reduced gravity, research has demonstrated these muscles that connect the bones of the spine together shrink and weaken, particularly those in the lower back, as they are less required in space.
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