09-Dec-2019 - Max-Planck-Institut für Bildungsforschung

How extreme environmental conditions affect the human brain

Members of a polar research expedition have provided researchers from Charité – Universitätsmedizin Berlin and the Max Planck Institute for Human Development with an opportunity to study the effects of social isolation and extreme environmental conditions on the human brain. The researchers found changes to the dentate gyrus, an area of the hippocampus responsible for spatial thinking and memory.

Setting off on an Antarctic expedition to Neumayer-Station III, a German Antarctic research station run by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), means having to face temperatures as low as -50 degrees Celsius (-58 degrees Fahrenheit) and almost complete darkness during the winter months. Life at the research station offers little in the way of privacy or personal space. Contact with the outside world is minimal, and cutting one’s stay short is not an option – at least not during the long winter months. Emergency evacuation and deliveries of food and equipment are only possible during the relatively short summer. “This scenario offers us the opportunity to study the ways in which exposure to extreme conditions affect the human brain,” says study lead Dr. Alexander Stahn of Charité’s Institute of Physiology and Assistant Professor at the Perelman School of Medicine at the University of Pennsylvania. Working alongside Prof. Dr. Simone Kühn (Group Leader of the Lise Meitner Group for Environmental Neuroscience at the Max Planck Institute for Human Development), and supported by the AWI, Alexander Stahn set out to determine whether or not an Antarctic expedition produces changes to the structure and function of the human brain.

Five men and four women volunteered to participate in the study. They spent a total of 14 months at the Antarctic research station, 9 of which were spent in isolation from the outside world. Before, during and after their mission, the participants completed a set of computer-based cognitive tests. These included evaluations of concentration, memory, cognitive reaction time and spatial thinking. Regular blood tests were carried out to measure levels of a specific growth factor known as brain-derived neurotrophic factor (BDNF), a protein responsible for promoting the growth of nerve cells and synapses in the brain. The researchers used magnetic resonance imaging to determine brain structure in each of the participants before and after their mission. They did so in order to record changes in brain volume, paying particular attention to the hippocampus, a structure located deep inside the brain. “For this, we used a high-resolution methodology which makes it possible to take precise measurements of individual areas of the hippocampus,” says Prof. Kühn. A group of nine control participants underwent identical tests.

Measurements taken after the end of the exhibition revealed that the dentate gyrus, an area of the hippocampus with an important role in spatial thinking and memory formation, was smaller in members of the expedition team than in controls. These changes were also associated with a decrease in BDNF levels. After only three months in the Antarctic, levels of the growth factor had decreased to levels below those recorded prior to the start of the expedition and had not returned to normal one-and-a-half months after the expedition. Cognition tests showed effects on both spatial abilities and the so-called selective attention, which is necessary to ignore irrelevant information. Repeated testing is normally associated with improvements in test results. This learning effect, however, was reduced in participants whose dentate gyrus had decreased in volume, the reduction proportional to the extent of the volume lost.

“Given the small number of participants, the results of our study should be viewed with caution,” explains Dr. Stahn, adding: “They do, however, provide important information, namely – and this is supported by initial findings in mice – that extreme environmental conditions can have an adverse effect on the brain and, in particular, the production of new nerve cells in the hippocampal dentate gyrus.” As a next step, the researchers plan to study whether or not physical exercise might be able to counteract the observed changes in the brain.

Facts, background information, dossiers
  • brain
More about Max-Planck-Institut für Bildungsforschung
More about Max-Planck-Gesellschaft
  • News

    Cancer-like metabolism and human brain size evolution

    The size of the human brain increased profoundly during evolution. A certain gene that is only found in humans triggers brain stem cells to form a larger pool of stem cells. As a consequence, more neurons can arise, which paves the way to a bigger brain. This brain size gene is called ARHGA ... more

    Body cells spy out bacteria

    Bacterial infection does not automatically lead to illness; many germs only become dangerous when they occur in large numbers. Researchers at the Max Planck Institute for Infection Biology in Berlin have discovered that the body has a receptor, which doesn’t recognize bacteria themselves, b ... more

    Synchro swimmers under the microscope

    Not only birds, fish and even crowds of people show collective movement patterns, motile bacteria also form currents and vortices when their cell density exceeds a certain size. Researchers at the Max Planck Institute for terrestrial Microbiology in Marburg have now been able to show how sw ... more

  • Videos

    Epigenetics - packaging artists in the cell

    Methyl attachments to histone proteins determine the degree of packing of the DNA molecule. They thereby determine whether a gene can be read or not. In this way, environment can influence the traits of an organism over generations. more

    Biomaterials - patent solutions from nature

    Animals and plants can produce amazing materials such as spider webs, wood or bone using only a few raw materials available. How do they achieve this? And what can engineers learn from them? more

    Chaperones - folding helpers in the cell

    Nothing works without the correct form: For most proteins, there are millions of ways in which these molecules, composed of long chains of amino acids, can be folded - but only one way is the right one. Researchers in the department "Cellular Biochemistry" at the Max Planck Institute for Bi ... more

  • Research Institutes

    Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V.

    The research institutes of the Max Planck Society perform basic research in the interest of the general public in the natural sciences, life sciences, social sciences, and the humanities. In particular, the Max Planck Society takes up new and innovative research areas that German universiti ... more

More about Charité
  • News

    Hundreds of novel viruses discovered in insects

    New viruses which cause diseases often come from animals. Well-known examples of this are the Zika virus transmitted by mosquitoes, bird flu viruses, as well as the MERS virus which is associated with camels. In order to identify new viral diseases quickly and prevent possible epidemics, DZ ... more

    New gene therapy for epilepsy provides on-demand release of endogenous substance

    Teams of researchers from Charité - Universitätsmedizin Berlin and the Medical University of Innsbruck have developed a new therapeutic concept for the treatment of temporal lobe epilepsy. It represents a gene therapy capable of suppressing seizures at their site of origin on demand. Having ... more

    Machine learning improves cancer diagnosis

    Researchers from Charité – Universitätsmedizin Berlin and the German Cancer Consortium (DKTK) have successfully solved a longstanding problem in the diagnosis of head and neck cancers. Working alongside colleagues from Technische Universität (TU) Berlin, the researchers used artificial inte ... more

  • Research Institutes

    Charité - Universitätsmedizin Berlin

    The Charité is one of the largest university hospitals in Europe. Here, 3800 doctors and scientists heal, do research and teach at the top international level. More than half of the German Nobel Prize winners in medicine and physiology come from the Charité, among them Emil von Behring, Ro ... more