Featured Research

from universities, journals, and other organizations

Critical link in mammalian odor detection identified

Date:
May 6, 2013
Source:
Monell Chemical Senses Center
Summary:
Researchers at the Monell Center have identified a protein that is critical to the ability of mammals to smell. Mice engineered to be lacking the Ggamma13 protein in their olfactory receptors were functionally anosmic – unable to smell. The findings may lend insight into the underlying causes of certain smell disorders in humans.

Researchers at the Monell Center and collaborators have identified a protein that is critical to the ability of mammals to smell. Mice engineered to be lacking the Ggamma13 protein in their olfactory receptors were functionally anosmic -- unable to smell. The findings may lend insight into the underlying causes of certain smell disorders in humans.

"Without Ggamma13, the mice cannot smell," said senior author Liquan Huang, PhD, a molecular biologist at Monell. "This raises the possibility that mutations in the Ggamma13 gene may contribute to certain forms of human anosmia and that gene sequencing may be able to predict some instances of smell loss."

Odor molecules entering the nose are sensed by a family of olfactory receptors. Inside the receptor cells, a complex cascade of molecular interactions converts information to ultimately generate an electrical signal. This signal, called an action potential, is what tells the brain that an odor has been detected.

To date, the identities of some of the intracellular molecules that convert odor information into an action potential remain a mystery. Suspecting that a protein called Ggamma13 might be involved, the research team engineered mice to be lacking this protein and then tested how the 'knockout' mice responded to odors.

Importantly, because the Ggamma13 protein plays important roles in other parts of the body, the Ggamma13 'knockout' was confined exclusively to smell receptor cells. This specificity allowed the researchers to characterize the effect of Ggamma13 deletion on the olfactory system without interference from changes in other tissues.

Both behavioral and physiological experiments revealed that the Ggamma13 knockout mice did not respond to odors. The findings were published in The Journal of Neuroscience.

In behavioral tests, control mice with an intact sense of smell were able to detect and retrieve a piece of buried food in less than 30 seconds. However, mice lacking Ggamma13 in their olfactory cells required more than 8 minutes to perform the same task. Both sets of mice were able to quickly locate the food when it was placed in plain sight.

A second set of experiments measured olfactory function on a physiological level. Using olfactory tissue from knockout and control mice, the researchers recorded electrical responses to 15 different odors. Responses from the Ggamma13 knockout mice were greatly reduced, suggesting that the olfactory receptors of these mice were unable to translate odor signals into an electrical response.

Together, the findings demonstrate that Ggamma13 is essential for mammals to smell odors and extend the current understanding of how olfactory receptor cells communicate information about odors to the brain. Future studies will seek to identify how Ggamma13 interacts with other molecules within the olfactory receptor.

"Loss of olfactory function can greatly reduce quality of life," said Huang. "Our findings demonstrate the significant consequences when just one molecular component of this complex system does not function properly."

Also contributing to the research were lead author Feng Li, Samusudeen Ponissery-Saidu, Karen Yee, Hong Wang, Naoko Iguchi, and Johannes Reisert from Monell; Meng-Ling Chen and Genhua Zhang from the Changshu Institute of Technology in China; and Ping Jiang from the Wistar Institute. The research was supported by the National Institute on Deafness and Other Communication Disorders, part of the National Institutes of Health, under award numbers R01DC007487, R01DC009613, and DC010012, and core facility grant P30 DC011735. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Additional funding came from National Science Foundation Equipment Grant DBI-0216310 and National Natural Science Foundation of China Grant 31228008.


Story Source:

The above story is based on materials provided by Monell Chemical Senses Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. F. Li, S. Ponissery-Saidu, K. K. Yee, H. Wang, M.-L. Chen, N. Iguchi, G. Zhang, P. Jiang, J. Reisert, L. Huang. Heterotrimeric G Protein Subunit G13 Is Critical to Olfaction. Journal of Neuroscience, 2013; 33 (18): 7975 DOI: 10.1523/JNEUROSCI.5563-12.2013

Cite This Page:

Monell Chemical Senses Center. "Critical link in mammalian odor detection identified." ScienceDaily. ScienceDaily, 6 May 2013. <www.sciencedaily.com/releases/2013/05/130506161236.htm>.
Monell Chemical Senses Center. (2013, May 6). Critical link in mammalian odor detection identified. ScienceDaily. Retrieved April 20, 2014 from www.sciencedaily.com/releases/2013/05/130506161236.htm
Monell Chemical Senses Center. "Critical link in mammalian odor detection identified." ScienceDaily. www.sciencedaily.com/releases/2013/05/130506161236.htm (accessed April 20, 2014).

Share This



More Plants & Animals News

Sunday, April 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins