Depression and schizophrenia can be triggered by environmental stimuli and often occur in response to stressful life events. However, some people have a higher predisposition to develop these diseases, which highlights a role for genetics in determining a person's disease risk.
A high number of people with depression have a genetic change that alters a protein that cells use to talk to each other in the brain. Imaging of people with depression also shows that they have greater activity in some areas of their brain. Unfortunately, the techniques that are currently available have not been able to determine why stress induces pathological changes for some people and how their genetics contribute to disease.
A new mouse model may provide some clues about what makes some people more likely to develop depression after experiencing stress. A collaborative group of European researchers created a mouse that carries a genetic change associated with depression in people. "This model has good validity for understanding depression in the human, in particularly in cases of stress-induced depression, which is a fairly widespread phenomenon" says Dr. Alessandro Bartolomucci, the first author of the research published in the journal, Disease Models and Mechanisms (DMM).
The scientists made genetic changes in the transporter that moves a signaling protein, serotonin, out of the communication space between neurons in the brain. The changes they made are reminiscent of the genetic changes found in people who have a high risk of developing depression.
"There is a clear relationship between a short form of the serotonin transporter and a very high vulnerability to develop clinical depression when people are exposed to increasing levels of stressful life events." says Dr. Bartolomucci, "This is one of the first studies performed in mice that only have about 50% of the normal activity of the transporter relative to normal mice, which is exactly the situation that is present in humans with high vulnerability to depression".
Mice with the genetic change were more likely to develop characteristics of depression and social anxiety, which researchers measure by their degree of activity and their response to meeting new mice. The work from this study now allows researchers to link the genetic changes that are present in humans with decreased serotonin turnover in the brain. It suggests that the genetic mutation impedes the removal of signaling protein from communication areas in the brain, which may result in an exaggerated response to stress.
Dr. Bartolomucci points out that many of the chemical changes they measured occurred in the areas of the brain that regulate memory formation, emotional responses to stimuli and social interactions, which might be expected. "What we were surprised by was the magnitude of vulnerability that we observed in mice with the genetic mutation and the selectivity of its effects".
This work is presented in the Research Article entitled 'Increased vulnerability to psychosocial stress in heterozygous serotonin transporter knockout mice', written by Alessandro Bartolomucci, Stefano Parmigiani and Paola Palanza from University of Parma in Italy, Valeria Carola, Tiziana Pascucci, Stefano Puglisi-Allegra, and Simona Cabib from the Univeristy of Rome La Sapienza in Italy and Klaus-Peter Lesch from the Univeristy of Wurzburg in Germany and Cornelius Gross from the European Molecular Biology Laboratory (EMBL) in Italy. The study is published in Volume 3 issue 7/8 of the research journal, Disease Models & Mechanisms (DMM), http://dmm.biologists.org/, published by The Company of Biologists, a non-profit organisation based in Cambridge, UK.
About Disease Models & Mechanisms:
Disease Models & Mechanisms (DMM) (http://dmm.biologists.org) is a new research journal, launched in 2008, that publishes primary scientific research, as well as review articles, editorials, and research highlights. The journal's mission is to provide a forum for clinicians and scientists to discuss basic science and clinical research related to human disease, disease detection and novel therapies. DMM is published by the Company of Biologists, a non-profit organization based in Cambridge, UK.
The Company also publishes the international biology research journals Development, Journal of Cell Science, and The Journal of Experimental Biology. In addition to financing these journals, the Company provides grants to scientific societies and supports other activities including travelling fellowships for junior scientists, workshops and conferences. The world's poorest nations receive free and unrestricted access to the Company's journals.
The genes are not to blame
20.07.2018 | Technische Universität München
Targeting headaches and tumors with nano-submarines
20.07.2018 | Universitätsmedizin der Johannes Gutenberg-Universität Mainz
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences