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. 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 October 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 October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
Captive Dolphin Gives Birth

Captive Dolphin Gives Birth

Reuters - Light News Video Online (Oct. 20, 2014) SeaWorld in San Diego welcomes a new bottlenose dolphin, the second calf for 13-year-old female, Sadie. Rough Cut. (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Another Study Suggests Viagra Is Good For The Heart

Another Study Suggests Viagra Is Good For The Heart

Newsy (Oct. 20, 2014) An ingredient in erectile-dysfunction medications such as Viagra could improve heart function. Perhaps not surprising, given Viagra's history. Video provided by Newsy
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. 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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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