Brains in Space!

Fake it until you make itGravity

Posted by Kim Jan 16, 2019 12:10PM

In the almost 60 years since we’ve started launching humans into space, more than 550 have been [1], [2]. That isn’t a lot of people when you’re looking for research data. Additionally, obtaining data on space travel can be costly and has limitations. For example, certain data collecting methodologies are not possible in space, like magnetic resonance imaging (fMRI). This means that data needs to be collected before and after the astronauts go into space. In certain cases, data collected after space travel is time sensitive and getting data too late can affect the analyses made from that data. This presents some potential obstacles for research. Real space data like this is not necessarily pro-active in the sense that we are putting humans in space in order to determine possible detrimental effects.

Fortunately scientists have developed analogues to mimic certain aspects of space travel here on earth. This allows scientists to gather data and study the effects of space on the brain and other aspects of the human body in a safe controlled environment. Of course, no technique is a perfect analogue for space, but they can give us a better understanding of what the factors are that we are dealing with in order to help us create countermeasures.

So what are the analogues?

Parabolic Flight (PF):

Parabolic flight was first introduced in the 1950’s as a way to train astronauts in microgravity.

Blog image

Figure 1. The illustration shows the general trajectory of a parabolic flight. It shows that several gravities are created during flight; hypergravity, microgravity, and Earth gravity. It also shows the general time course for each gravity. Data from Van Ombergen et al, 2017.

Figure 1 illustrates a general parabolic flight pattern and the relatively short timespan in which to experience microgravity. Parabolic flight offers several different gravities for study, including normal gravity (1g), hypergravity (1.5-1.8g), and microgravity (0g). Additionally, different flight alterations can offer Martian gravity (.38g) and lunar gravity (.16g). Microgravity or zero gravity (0g) is roughly 20-25 seconds in length [3], [4]. This is often repeated 30-60 times.

Dry Immersion:

Dry immersion was first used in the 1970’s as a way to test the effects of weightlessness. Dry immersion is a technique where a subject is immersed in thermo-neutral water. The subject is covered with a waterproof fabric in order to keep them completely dry and prevents contact with the water. This method recreates the supportlessness, confinement, immobilization, centralization of bodily fluids, and reduced muscle movement (hypokinesia) that astronauts face in space [3],[5].

Blog image

Figure 2. An image showcasing dry immersion. Image from Navasiolava et al., 2011.

They can be horizontal as in Figure 2 or upright such as sitting or standing. Immersions can last anywhere from a few days up to a few weeks.

Head Down Bed Rest (HDBR):

The use of bed rest to study the effects of inactivity on the human body has been conducted since the late 1940’s. However, using the head down method to simulate the body in space wasn’t used until the 1970s [6]. It entails immobilizing a subject at a six degree angle which causes cephalic fluid (cerebrospinal fluid in brain) shifting [3], [6]. This method is meant to recreate the immobilization, isolation, and monotony that astronauts are subjected to in space. However, unlike space, this method still allows for gravitation as well as a sense of balance.

Blog image

Figure 3. Subjects are confined to beds at a six degree angle. Image from nasa.gov.

What these analogues allow scientists to do is to learn what the risks and effects of space are on the human body in a controlled environment. They offer more opportunities for testing then would be available just using real astronauts alone. The accumulation of this sort of data will enable the development of better and safer ways for people to travel in space. If our future is in the stars, then we better figure out how to prevent problems before we get there.

Resources:

[1] Holmes, O. Space: How Far Have We Gone-and Where are We Going? [Internet]. New York (NY): Guardian News and Media Limited; c2019 [updated 2018 Nov 19; cited 2019 Jan 15]. Available from: https://www.theguardian.com/science/2018/nov/19/space-how-far-have-we-gone-and-where-are-we-going

[2] Astronaut/Cosmonaut Statistics [Internet]. [publisher unknown] [place unknown] [updated 2019 Jan 16; cited 2019 Jan 15]. Available from: https://www.worldspaceflight.com/bios/stats.php

[3] Van Ombergen, A., Demertzi, A., Tomilovskaya, E., Jeurissen, B., Sijbers, J., Kozlovskaya, I.B., Parizel, P.M., Van de Heyning, P.H., Sunaert, S., Laureys, S., Wuyts, F.L. The Effect of Spaceflight and Microgravity on the Human Brain. Journal of Neurology. 2017, 264(1): S18-S22.

[4] Karmali, F., Shelhamer, M. The Dynamics of Parabolic Flight: Flight Characteristics and Passenger Percepts. Acta Astronautica. 2008, 63(5-6): 594-602.

[5] Navasiolava, N. M., Custaud, M., Tomilovskaya, E. S., Larina, I.M., Mano, T., Gauquelin-Koch, G., Gharib, C., Kozlovskaya, I.B. Long-Term Dry Immersion: Review and Prospects. European Journal of Applied Physiology. 2011, 111(7): 1235-1260.

[6] Pavy-Le Traon, A., Heer, M., Narici, M.V., Rittweger, J., Vernikos, J. From Space to Earth: Advances in Human Physiology from 20 years of bed rest studies (1986-2006). European Journal of Applied Physiology. 2007, 101(2): 143-194.

[7] Edwards, M., Abadie, L. Lying in Bed for the Sake of Science: NASA Co-Sponsors Bed Rest Study in Germany. [Internet]. Washington (DC): National Aeronautics and Space Administration; c2018 [updated 2018 Aug 16; cited 2019 Jan 15]. Available from: https://www.nasa.gov/feature/lying-in-bed-for-the-sake-of-science-nasa-co-sponsors-bed-rest-study-in-germany



Starrider – take me to the starsInfinity and Beyond

Posted by Kim Oct 26, 2018 09:53AM

In 1961, the first human being was launched into space, Yuri Gagarin, shortly followed by Alan Shepard less than a month later [1]. At the time of writing this, that is roughly fifty-seven years ago. Before that time, space flight was simply fantasy, the stuff of sci-fi writing, the stuff of the future. Now, space travel is not only our future, but it’s both our present and past. We have history with space now; a position that wasn’t even conceivable sixty years ago. Who would ever believe that space travel would be part of our history as human beings?

Regardless of our past, space is still the future, with active plans being made for travel to Mars. Mars, a trip that would take almost a year (roughly 7 to 8 months) in flight and another 2 years on the planet just to be at the right alignment to fly back home (when Mars is the closest to Earth in its orbit) [2]. The big question as I see it though, is can humans take it? I mean, life as we know it, humans included, has evolved and developed to adapt to conditions on Earth. Earth, a planet with a gravitational force of 1g, a cushy protective atmosphere, delicious nutrients, and a cozy heating system [3]. What if we take all that away? What happens to our bodies with no gravity or with more gravity? How do we account for the hostile environment without our atmosphere to act as security blanket? What if?

Although we may know more about the universe, our solar system, and technology in general than we did fifty-seven years ago, there are still a lot we don’t know about humans in space. It’s somewhat common knowledge that astronauts returning home after time in space have muscle atrophy and loss of bone density [4], [5]. Although these are serious issues that need to be resolved for long-term space habitation, the brain runs the show. So what happens to our brains?

There is a theoretical debate that the human mind is the most complex object in the universe. Although I won’t go into specifics of the debate here, what it illustrates is just how complex and important the brain is. The brain regulates breathing, balance, coordination, motor control, vision, emotion, hearing, analytical reasoning, problem solving, and language just to name a few of its functions. Without a fully functioning and reasoning brain, things will start to go awry, which is critical when you’re about 140 million miles away from home [6]. Like our bones and muscles, our brains developed with Earth’s gravity. What happens when you take that away?

My hope for upcoming posts is to explore what we do know about the affects of space on the brain. What have we observed with returning astronauts? What sorts of experiments are we doing on earth to simulate conditions in space? What are the acting forces and what are the long-term effects? What are the questions we should be asking?


Resources:

[1] “Early Manned Spaceflight.” Internet: https://www.nationalgeographic.com/science/space/space-exploration/early-manned-spaceflight/, [Oct.26, 2018].

[2] “How long does it take to travel to Mars?” Internet: https://www.mars-one.com/faq/mission-to-mars/how-long-does-it-take-to-travel-to-mars, [Oct.26, 2018].

[3] “What is G Force?” Internet: http://www.gforces.net/what-is-g-force-meaning.html, [Oct.26, 2018].

[4] “Musculo-Skeletal System: Bone and Muscle Loss.” Internet: https://www.esa.int/Our_Activities/Preparing_for_the_Future/Space_for_Earth/Space_for_health/Musculo-skeletal_system_Bone_and_Muscle_loss, April 26, 2017 [Oct.26, 2018].

[5] E. Endo, “Researchers study impact of space radiation on bone and muscle health.” Internet: https://phys.org/news/2017-12-impact-space-bone-muscle-health.html, Dec. 14, 2017 [Oct.26, 2018].

[6] “How far is it to Mars?” Internet: https://sservi.nasa.gov/articles/how-far-is-it-to-mars/, [Oct.26, 2018].