The absence of a key signaling protein in the brain during infancy could lead to anxiety disorders later in life, scientists say. According to findings published today in the journal Nature, mice lacking the receptor protein for the chemical messenger serotonin just after birth exhibit abnormal anxiety as adults.
Researchers have known for some time that mice genetically engineered to lack the receptor for serotonin, a neurotransmitter, show anxiety-like behavior. But the new results go one step further, revealing when in life and where in the brain the link between serotonin receptors and anxiety behavior is forged. As in earlier studies, the investigators, led by René Hen of Columbia University, first created a line of so-called knockout mice that lacked the gene encoding the receptor protein. Those mice showed the expected signs of anxiety, such as moving around less open spaces and taking longer to start eating in new environments as compared with normal animals. To determine which of the two receptor populations--the one in the forebrain or the one in the brainstem--is most critical in that regard, the team then crossed the knockout mice with a line engineered to activate receptor expression in particular brain regions. The resulting line of double-transgenic "rescue" animals expressed the serotonin receptors only in the forebrain, but exhibited normal anxiety behavior. Further tests, in which the drug doxycycline was used to suppress the receptors in mice at various stages of development, showed that eliminating the receptors in juvenile or adult mice did not elicit over-anxiousness.
"Forebrain serotonin receptors are needed during the development of newborns to modulate the predisposition to anxiety-like behavior, but are no longer critical during adult life," Solomon Snyder of Johns Hopkins University explains in a commentary accompanying the report. He proposes that variations in serotonin-sensitive neurons and serotonin receptors early in life might account for the importance of maternal nurturing in preventing emotional disorders later in life. Rats that were not groomed sufficiently as pups by their mothers display elevated levels of anxiety as adults, he notes. "Assuming that we can equate developmental stages in mice and humans," Snyder reflects, "these findings might be relevant to brain development and the genesis of anxiety in people too."
Kate Wong | Scientific American
New catalyst controls activation of a carbon-hydrogen bond
21.11.2017 | Emory Health Sciences
The main switch
21.11.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
21.11.2017 | Physics and Astronomy
21.11.2017 | Physics and Astronomy
21.11.2017 | Life Sciences