Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

On the Tip

10.12.2003


USC researcher Liman investigates taste buds -- made up of bundles of 50 to 100 taste cells -- to better understand how animals detect sweet, bitter and umami flavors.

Photo/Rudy Moro


Put a caramel in your mouth and your taste buds detect the sugary substance, instantly sending a message to the brain, which interprets the signal - sweet!

Trying to figure out what happens in the split-second between eating something and recognizing its sweet or bitter flavor - between detecting a taste and a signal reaching the brain - led USC neuroscientist Emily Liman to take a closer look inside the cells in the taste buds.

Her findings reveal new details about how the sense of taste works.



And calcium, said Liman, plays a key role in the detection of tastes by taste cells in the tongue.

The research by Liman, an assistant professor of biological sciences in the USC College of Letters, Arts & Sciences, and graduate student Dan Liu will be published in the Proceedings of the National Academy of Sciences this month. The paper also offers a molecular model of how taste cells reset so they are ready to detect new tastes.

The study appeared online Dec. 1 in the journal’s early edition.

Until recently, scientists have known little about how taste works on a cellular or molecular level. Just four years ago, scientists officially added a unique taste, called umami, to the list of the better known: sweet, bitter, salty and sour.

Umami receptors are sensitive to the amino acid glutamate, which most think serves as a marker for protein-rich foods.

Glutamate also is the main ingredient in the commonly used flavor additive MSG (monosodium glutamate), which may explain the additive’s appeal.

Taste research has attracted the attention of researchers like Liman who are interested in unraveling how cellular signaling works.

Food and drug industry scientists also are very interested in understanding the molecular details of taste, especially bitter and sweet, Liman said.

“It’s important to know how taste works and to identify the molecules involved,” she said. “These molecules can be targets for designing chemicals that activate taste - for example, a better artificial sweetener - or that block taste, such as an additive that could be used to block bitter tastes.”

In the study, Liman and Liu looked closely at a protein necessary for detecting sweet, bitter and umami tastes.

Without the protein, called TRPM5, mice can’t discern between the flavors.

Once activated, the protein appears to play a key role in the taste-signaling pathway, somehow sending a message to the brain about what’s been tasted..

Liman, who has investigated similar issues relating to the sense of smell and pheromone detection, studied how this protein worked in an experimental cell system.

She found that the protein acts like a gated bridge on the cell’s membrane, connecting the inside and outside of the cell. The gate opened when the researchers added calcium ions.

In general, proteins like TRPM5 are considered good potential drug targets because their position on the cell surface makes them more accessible than proteins inside the cell.

In other experiments, Liman and Liu figured out that the protein TRPM5 closes as it undergoes desensitization to taste.

Desensitization is what allows a person to adapt to a strong taste or smell over time, perhaps barely noticing it after a while.

The researchers also found that the TRPM5 protein gate opens up again through an interaction with another cellular molecule called PIP2.

Liman cautioned that her team has yet to show conclusively that calcium is responsible for the initiation of the signal to the brain.

To prove this, she will have to see whether her laboratory studies apply to taste cells in living animals, experiments she hopes to start soon.

Eva Emerson | USC
Further information:
http://www.usc.edu/uscnews/story.php?id=9616

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>