Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Brain chemical serotonin involved in early embryo patterning

10.05.2005


Discovery provides keys to evolution of neuronal signalling, ’left-right asymmetry’



Boston--Forsyth Institute researchers have found that serotonin-the chemical substance involved in transmitting signals between neurons and which plays a role in anxiety and mood disorders-- is present in vertebrate embryos long before neurons form. The scientists also found that serotonin plays a key role in determining where organs are positioned in the body during embryonic development.

The study, published in the May 10 Current Biology, has ramifications for neuroscience, developmental genetics, evolutionary biology and, possibly, human teratology (a branch of pathology and embryology concerned with abnormal development and congenital malformations).


Among other results, the study, which was carried out on frog and chick embryos:

  • Provides the first molecular support for the idea that serotonin is utilized as a large-scale left-right patterning mechanism, thus offering new insight into the basis of position of the heart and other asymmetric, visceral organs.
  • Identifies a possible novel serotonin signaling pathway, providing evidence that serotonin can signal inside the cell. If also found in mammals, such signaling, which may be important in brain functioning, would suggest numerous new roles and possible targets for serotonin-related drugs like the selective serotonin reuptake inhibitors (SSRI antidepressants such as Prozac and Zoloft) or the monoamine oxidase inhibitors (MAOIs).
  • Could lead to a greater understanding of potential health risks from drug families that target the serotonin pathway in human patients.
  • Sheds light on the evolutionary origin of a crucial neurological control system, suggesting that neuronal synapses using serotonin as a neurotransmitter may have arisen through the adaptation of ancient, fundamental cell-cell signals to a new purpose as nervous systems evolved.

The team was led by principal investigator Michael Levin, PhD, Associate Member of the Staff, whose laboratory focuses on understanding the role played by flows of ions and other small molecules in determining body patterning during embryonic development and regeneration. According to Levin, "We hope that through better understanding of important but previously little-studied biophysical signals, new therapeutic applications can be developed."

One important goal is to find ways to prevent or treat laterality-related birth defects such as isomerism (a loss of asymmetry such as when a body has a midline heart or two spleens), heterotaxia (in which various organs are randomly located on the correct or incorrect sides of the body), or situs inversus (in which all organs are located on the opposite side of the body)." Such defects affect about one in 8 thousand babies born to term.

The Study

In the current study, the researchers found that frog embryos contain a supply of serotonin provided in the egg by the mother. This maternal supply of serotonin functions during the first few cell divisions and then is degraded by an enzyme (Monoamine Oxidase) which has many important functions in human neuro-medicine. Chick embryos, on the other hand, synthesize their own serotonin shortly after laying. Though details (such as the origin of the serotonin) differ, both species utilize serotonin signaling as a patterning mechanism long before the appearance of the nervous system-- suggesting that this novel role for serotonergic signaling may be conserved in a number of different species.

SIGNIFICANCE

Evolutionary Biology

Regarding the study’s evolutionary significance, Levin said: "This work demonstrates that a signaling mechanism previously believed to exist only in neuronal synapses is, in fact, also a signal used by communicating primitive embryonic cells--thus illustrating a fascinating re-use of cellular control systems in evolution. The mechanism can now be studied in a wide selection of organisms as scientists work to understand the most common and fundamental mechanisms guiding pattern formation across phyla."

Clinical

Jean M. Lauder, Ph.D., Professor of Cell and Developmental Biology at the University of North Carolina School of Medicine at Chapel Hill said: " Dr. Levin’s team presents exciting new evidence that serotonin, a brain chemical or "neurotransmitter" that is involved in mood disorders and depression and is targeted by antidepressants like Prozac, plays critical roles in early embryonic (prenatal) development of left-right asymmetry of body organs like the heart, gall bladder, and gut.

"This is the first time that a "neurotransmitter" has ever been shown to be a critical patterning signal during development of the vertebrate body plan. This study provides evidence that early embryonic cells have ways of sensing serotonin other than by the synaptic mechanisms that have previously been described in the nervous system.

"Although neurotransmitters like serotonin are known to regulate development of cells and tissues outside the nervous system, no study has ever before shown that they could regulate such things as the shape, laterality, or placement of tissues or organs in the body.

"The possible clinical significance is that serotonergic drugs, if taken by the pregnant woman, might disrupt normal development of the body plan in the fetus. This study also opens up new possibilities for drug discovery to find therapies to prevent malformations caused by errors in these important aspects of prenatal serotonergic signaling."

Embryonic Asymmetry

In the words of Professor Dr. Martin Blum of the University of Hohenheim Institute of Zoology: "Dr. Levin’s fascinating new data add to the mounting evidence for a cilia-independent mechanism of symmetry breakage in the frog which acts very early, during the first few cell divisions. It will be extremely exciting to find out how serotonin signaling connects to the left-asymmetric signaling cascade, and if and how such a mechanism is conserved in other vertebrates, particularly the mouse."

Medical, Neurological

Lewis Wolpert, FRS Emeritus Professor of Biology as Applied to Medicine, Anatomy, and Developmental Biology at the University College, London said: The study is "very impressive and totally unsuspected. This is a rare truly novel finding opening up a new world in development of asymmetry and perhaps more. Who would have thought that depression might be related to handedness?"

Anita Harris | EurekAlert!
Further information:
http://www.forsyth.org/

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>