Sudden Infant Death Syndrome (SIDS) is a condition that unexpectedly and unexplainably takes the lives of seemingly healthy babies aged between a month and a year.
Now researchers of the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, have developed a mouse model of the so-called crib or cot death, which remains the leading cause of death during the first year of life in developed countries. The model, published in this week’s issue of Science, reveals that an imbalance of the neuronal signal serotonin in the brainstem is sufficient to cause sudden death in mice.
The brainstem, the lower part of the brain that forms the link to the spinal cord, coordinates many fundamental functions including control over cardiovascular and respiratory systems. Victims of SIDS show alterations in those brainstem neurons that communicate using the signalling molecule serotonin. Cornelius Gross and his group at the EMBL Mouse Biology Unit modified the serotonin system of mice to understand the role of this signalling molecule in the brainstem. They overexpressed an important receptor that regulates serotonin signalling, called serotonin 1A autoreceptor.
“At first sight the mice were normal. But then they suffered sporadic and unpredictable drops in heart rate and body temperature. More than half of the mice eventually died of these crises during a restricted period of early life. It was at that point that we thought it might have something to do with SIDS,” says Gross.
Until now it was unclear how changes in serotonin signalling in the brainstem of SIDS infants are involved in sudden death. The findings in the mouse show that deficits in serotonin signalling in the brainstem can be sufficient to cause sudden death and strongly support the idea that a congenital serotonin defect could play a critical role in SIDS.
Serotonin neurons in the brainstem communicate to nerve cells in the spinal cord that innervate the heart and organs involved in temperature regulation such as brown fat tissue. This signalling is defective in the mouse model of SIDS. For example, when placed into a cold chamber the animals cannot properly activate brown fat tissue to produce heat. This inability to activate fundamental body systems under certain conditions is likely to explain why the mice succumb to sudden death.
While a complete block of serotonin signalling does not lead to death, upsetting its intricate balance by overexpressing serotonin 1A autoreceptor can. In response to serotonin the receptor initiates a negative feedback mechanism that reduces serotonin release and dampens down the signal to the body. The researchers caution, however, that it is unlikely that the exact same molecular mechanism leads to SIDS in humans. Nevertheless, the mouse model will help to shed light on how serotonin signalling, when dysfunctional, can be life-threatening.
“We hope the mouse model will help identify risk factors for SIDS. One open question is whether like in SIDS, the animals die during sleep and whether we can identify which mice will die by looking at their heart rate or body temperature before the crisis. Ultimately, we hope it will give new ideas to doctors about how to diagnose babies at risk for SIDS,” says Enrica Audero, who carried out the research in Gross’ lab.
Anna-Lynn Wegener | EMBL
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences