In combination with earlier evidence, the findings suggest the so-called muscarinic acetylcholine pathway might play a conserved role in animals’ starvation response, the researchers said. The new findings might ultimately yield insights into the connection between eating disorders and an abnormal response to hunger or starvation, they suggest.
"In the nematode worm C. elegans, starvation causes a variety of changes in development, longevity, and behavior," said Young-jai You of the University of Texas Southwestern Medical Center. One such behavioral change involves alterations to the animals’ main feeding organ, the pharynx.
The worms eat by "pumping" bacteria in via relaxation and contraction of their pharyngeal muscle--an activity controlled by their internal feeding status. However, the signal responsible for changes in pumping rate had yet to be found.
The research team now reports that starvation activates the enzyme MAPK in the pharyngeal muscles of C. elegans through a muscarinic acetylcholine receptor. Mutations and drugs that prevented any step of the signal from muscarinic receptor to MAPK blocked the effects of starvation on the feeding muscle, they found. Furthermore, an excess of MAPK in normal worms mimicked the effect of starvation on the muscle.
"In mammals, muscarinic acetylcholine receptors regulate heart muscle and smooth muscle of the [digestive] tract, and MAPK signaling activation downstream of muscarinic acetylcholine receptors has been widely noted," wrote Kaveh Ashrafi in a Preview. "Moreover, there are intriguing but conflicting reports on the role of the receptors in growth rate and body weight of rodents.
"It is therefore plausible that molecular mechanisms that mediate starvation responses of C. elegans pharyngeal muscle are conserved across phylogeny," Ashrafi said.
The findings might help to unravel the factors underlying eating disorders, the researchers said.
"Despite the prevalence of feeding disorders from obesity to anorexia, the identity and mechanism of action of starvation signals are largely unknown," You’s team added. "Our study of starvation sensitivity of gpb-2 mutants and the downstream signaling pathway in feeding muscles suggests that feeding disorders may result from inappropriate behavioral responses to starvation signals."
Heidi Hardman | EurekAlert!
Flow of cerebrospinal fluid regulates neural stem cell division
21.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
21.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.
Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...
A team of scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg investigated optically-induced superconductivity in the alkali-doped fulleride K3C60under high external pressures. This study allowed, on one hand, to uniquely assess the nature of the transient state as a superconducting phase. In addition, it unveiled the possibility to induce superconductivity in K3C60 at temperatures far above the -170 degrees Celsius hypothesized previously, and rather all the way to room temperature. The paper by Cantaluppi et al has been published in Nature Physics.
Unlike ordinary metals, superconductors have the unique capability of transporting electrical currents without any loss. Nowadays, their technological...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
18.05.2018 | Power and Electrical Engineering
18.05.2018 | Information Technology
18.05.2018 | Information Technology