Navigation Links
Sour research, sweet results

This Thanksgiving, when you bite into the cranberry sauce and the tartness smacks your tongue as hard as that snide comment from your sister, consider the power of sour. Neurobiology researchers at the University of Southern California have made a surprising discovery about how some cells respond to sour tastes.

Of the five taste sensations sweet, bitter, sour, salty and umami sour is arguably the strongest yet the least understood. Sour is the sensation evoked by substances that are acidic, such as lemons and pickles. The more acidic the substance, the more sour the taste.

Acids release protons. How protons activate the taste system had not been understood. The USC team expected to find protons from acids binding to the outside of the cell and opening a pore in the membrane that would allow sodium to enter the cell. Sodium's entry would send an electrical response to the brain, announcing the sensation that we perceive as sour.

Instead, the researchers found that the protons were entering the cell and causing the electrical response directly.

The finding is to be published this week in the Proceedings of the National Academy of Sciences (PNAS) journal.

"In order to understand how sour works, we need to understand how the cells that are responsive to sour detect the protons," said senior author Emily Liman, associate professor of neurobiology in the USC College of Letters, Arts and Sciences.

"In the past, it's been difficult to address this question because the taste buds on the tongue are heterogeneous. Among the 50 or so cells in each taste bud there are cells responding to each of the five tastes. But if we want to know how sour works, we need to measure activity specifically in the sour sensitive taste cells and determine what is special about them that allows them to respond to protons."

Liman and her team bred genetically modified mice and marked their sour cells with a yellow florescent protein. Then they recorded the electrical responses from just those cells to protons.

The ability to sense protons with a mechanism that does not rely on sodium has important implications for how different tastes interact, Liman speculates.

"This mechanism is very appropriate for the taste system because we can eat something that has a lot of protons and not much sodium or other ions, and the taste system will still be able to detect sour," she said. "It makes sense that nature would have built a taste cell like this, so as not to confuse salty with sour."

In the future, the research may have practical applications for cooks and the food industry.

"We're at the early stages of identifying the molecules that contribute to sour taste," Liman said. "Once we've understood the nature of the molecules that sense sour, we can start thinking about how they might be modified and how that might change the way things taste. We may also find that the number or function of these molecules changes during the course of development or during aging."


Contact: Pamela Johnson
University of Southern California

Related biology news :

1. Department of Energy supports carbon sequestration research, University of Miami receives $1.7 million
2. New orthopaedic society launched to promote research, use of biologic treatments
3. When it comes to sleep research, fruit flies and people make unlikely bedfellows
4. VCU survey: US public supports genetic research, testing and government spending on research
5. State fund advances titanium powder research, 9 other Iowa State projects
6. Genes from sweet pepper to fortify African banana against devastating wilt disease
7. Hopkins team discovers sweet way to detect prediabetes
8. A bittersweet warning for women with gestational diabetes
9. Kids now see fewer television ads for sweets and beverages, but more for fast food
10. UM School of Medicine scientists find hormone influences sensitivity to sweetness
11. Atrazine is the main weapon against weeds in sweet corn, with few alternatives
Post Your Comments:
(Date:10/29/2015)... , Oct. 29, 2015   MedNet Solutions , ... entire spectrum of clinical research, is pleased to announce ... Tech Association (MHTA) as one of only three finalists ... "Software – Small and Growing" category. The Tekne Awards honor ... have shown superior technology innovation and leadership. ...
(Date:10/29/2015)... , Oct. 29, 2015 Daon, a global ... it has released a new version of its ... North America have already installed ... also includes a FIDO UAF certified server component ... preparing to activate FIDO features. These customers include some ...
(Date:10/29/2015)... 2015  Connected health pioneer, Joseph C. Kvedar ... technology-enabled health and wellness, and the business opportunities that ... The Internet of Healthy Things . Long before ... existed, Dr. Kvedar, vice president, Connected Health, Partners HealthCare, ... moving care from the hospital or doctor,s office into ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... CITY , Nov. 24, 2015 /PRNewswire/ - Aeterna ... request of IIROC on behalf of the Toronto Stock ... news release there are no corporate developments that would ... --> --> About ... . --> Aeterna Zentaris is ...
(Date:11/24/2015)... PHILADELPIA, PA (PRWEB) , ... November 24, 2015 , ... ... young entrepreneurs at competitive events in five states to develop and pitch their BIG ... student projects from each state are competing for votes to win the title of ...
(Date:11/24/2015)... 24, 2015 --> ... report released by Transparency Market Research, the global non-invasive ... CAGR of 17.5% during the period between 2014 and ... Global Industry Analysis, Size, Volume, Share, Growth, Trends and ... testing market to reach a valuation of US$2.38 bn ...
(Date:11/24/2015)... SAN FRANCISCO , Nov. 24, 2015 /PRNewswire/ ... today announced that Emily Leproust, Ph.D., Twist Bioscience ... Piper Jaffray Healthcare Conference on December 1, 2015 ... Palace Hotel in New York City. ... . Twist Bioscience is on ...
Breaking Biology Technology: