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 O2 stable hydrogenases for applications
23.07.2018 | Max-Planck-Institut für Chemische Energiekonversion

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Detecting damage in non-magnetic steel with the help of magnetism

23.07.2018 | Materials Sciences

Researchers move closer to completely optical artificial neural network

23.07.2018 | Information Technology

Enabling technology in cell-based therapies: Scale-up, scale-out or program in-place

23.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>