Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Possible New Cell Type Found in Developing Inner Ear

12.06.2003


Dr. Paul Sohal



The answer to how the complex, cavernous inner ear forms from a mostly homogenous group of cells may be that it doesn’t, says a Medical College of Georgia researcher who has found a new cell type that appears to migrate to the developing ear.

Dr. Paul Sohal first saw the cells he named ventrally emigrating neural tube cells in 1995, following the path of newly formed nerves out of the developing neural tube.

His research published in the June issue of the International Journal of Developmental Neuroscience says one place VENT cells go is to the developing inner ear.



“One thing which has been a puzzle was how can a single source of cells gives rise to entirely different systems, functionally different systems,” Dr. Sohal, developmental biologist, says of the inner ear which is believed to be formed from the same cells that form the outer layer of skin or epidermis. The only other cell believed to be in the region is the pigment-producing melanocyte.

By day two of development in the chick embryo, Dr. Sohal’s animal model, the neural tube -- a tubular structure that gives rise to the brain and spinal cord -- has formed and is covered with a skin called the surface ectoderm. That same day, an area of the skin on either side and about midway down the neural tube begins to thicken into what is known as an auditory placode. This thickened area begins to move inward, eventually working free from surrounding tissue and, by day three, forms the otic vesicle that will become the inner ear. In humans this should happen in the second month of development.

“What we have found is that, at this stage, VENT cells begin to move in from the neural tube and mix with these cells,” Dr. Sohal says. He believes VENT cells provide a heterogeneous mix to the epidermal cells, which could help explain the ability of cells within the region to form so many different types of tissue.

The developed inner ear is a complex structure that enables hearing and balance. The visible outer ear focuses sound to the middle then inner ear, which contain the eardrum and three bones that convert sound energy into mechanical energy. The movement of the bones applies pressure to the cochlea, a snail-shaped, fluid-filled organ, converting sound to a stimulus that triggers the hair cells. The hair cells -- which can be lost to disease, trauma or a congenital defect -- are activated and send signals to the nerve and eventually the brain where sound is perceived.

Dr. Sohal has published studies that show VENT cells in many areas of the body, most recently in the heart, small intestines and stomach. Still, he is meeting with resistance from some fellow scientists who are skeptical that he has found the first new cell type to be identified in the embryo since 1868. Some say the cells are simply experimental artifacts.

He believes they are much more, that the cells not only can form the four major types of body tissue but that they are the source of stem cells.

“The data is intriguing,” says Dr. David J. Kozlowski, developmental geneticist at MCG who is studying hair cell regeneration within the zebrafish inner ear to try to understand how hair cells regenerate in fish and not mammals.

Dr. Kozlowski, who also directs MCG’s Transgenic Zebrafish Core Facility, is looking for VENT cells in the zebrafish, another developmental model, to see if he can document their existence. “It’s certainly worth investing some effort to see if they exist in fish and, if they do, where do they go,” he says.

Dr. Sohal, undaunted most days, says the ubiquitous cells go pretty much everywhere, at least everywhere he has looked to date. “I think this tells us they are a general phenomenon, that the cells have a fundamental role.”

Back inside the ear, Dr. Sohal is now looking to determine if VENT cells are part of functional units within the inner ear. “What we have to do is find out where they end up. Are they part of the cochlea? Are they part of the sensory organs?” he says.

His work is funded by the National Institutes of Health.

Toni Baker | Medical College of Georgia
Further information:
http://www.mcg.edu/news/2003NewsRel/Sohal.html

More articles from Life Sciences:

nachricht What Makes Stem Cells into Perfect Allrounders
27.06.2017 | Universität Zürich

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>