Featured Research

from universities, journals, and other organizations

Accurate taste perception relies on a properly functioning olfactory system

Date:
December 29, 2009
Source:
Brandeis University
Summary:
As anyone suffering through a head cold knows, food tastes wrong when the nose is clogged, an experience that leads many to conclude that the sense of taste operates normally only when the olfactory system is also in good working order. Evidence that the taste system influences olfactory perception, however, has been vanishingly rare -- until now.

As anyone suffering through a head cold knows, food tastes wrong when the nose is clogged, an experience that leads many to conclude that the sense of taste operates normally only when the olfactory system is also in good working order. Evidence that the taste system influences olfactory perception, however, has been vanishingly rare -- until now. In a novel study recently published in Nature Neuroscience, Brandeis researchers report just such an influence.

Neuroscientist Don Katz and colleagues discovered that if the taste cortex in rats is inactivated when a rat first smells an odor, at least a food odor, then the rat subsequently will only recognize the food associated with that odor if the taste cortex is again inactivated.

"We discovered that rats use their taste system to smell with, so when you knock out the taste cortex, even for an hour, as we did, you alter their sense of smell," explained Katz. The researchers wrote that "this is the only example of state dependency in neural circuit function of which we are aware."

Katz and his colleagues used a multi-step training process to test the interdependence of the taste and olfactory systems. In the first step, a demonstrator rat that had just eaten chow flavored with one of four spices was introduced to a subject rat, which then smelled the demonstrator rat's breath.

In the second step, the subject rat was offered two choices of chow: one dish with the same flavor previously consumed by the demonstrator rat and another with a different flavor. The subject rat reliably preferred the food that it had previously smelled on the demonstrator rat's breath the day before. The researchers concluded that the social "smell test" of rat's breath is a good enough cue for rats to prefer one food over another.

At the outset they predicted that the rat's sense of smell would not be affected by changes in its taste system. "But we were wrong," said Katz. "Most surprisingly, the rats whose taste cortex was knocked out again the next day preferred the chow that they had experienced in an altered state, with no taste cortex.

"We discovered in this experiment that the sensory systems don't work in isolation from each other, said Katz. "One part of the cortex takes direct input from the nose, and one part from the tongue, and while it's convenient to think that the nose and taste receptors operate independently, they don't."

Katz actually tested two possible explanations for the basic result: First, taste cortex might be an integral component of how the animal processes smells. Alternatively, it might be that taste cortex changes, or modulates, olfactory circuits rather than coding them, fundamentally changing perception of smell at that point in time. Such "incorrect" memories of smell apparently last across at least a week of the rats' lives, and perhaps forever.

The Katz lab is now using brain recordings to pinpoint which parts of the olfactory system are affected when taste cortex is silenced, and to characterize the nature of the interaction between the taste and smell systems during feeding.

"I am hoping that ultimately this discovery will help drive us to an entirely different approach to brain function," said Katz. "It doesn't make sense to probe one system separately from the other. Just like in a chorus, you can't appreciate the fullness of the music if you hear only the bass or the tenor in isolation."

Yaihara Fortis-Santiago was the first author of the study. Benjamin A. Rodwin, Selin Neseliler, and Caitlin E. Piette also contributed to the study.


Story Source:

The above story is based on materials provided by Brandeis University. Note: Materials may be edited for content and length.


Cite This Page:

Brandeis University. "Accurate taste perception relies on a properly functioning olfactory system." ScienceDaily. ScienceDaily, 29 December 2009. <www.sciencedaily.com/releases/2009/12/091222104909.htm>.
Brandeis University. (2009, December 29). Accurate taste perception relies on a properly functioning olfactory system. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2009/12/091222104909.htm
Brandeis University. "Accurate taste perception relies on a properly functioning olfactory system." ScienceDaily. www.sciencedaily.com/releases/2009/12/091222104909.htm (accessed April 18, 2014).

Share This



More Health & Medicine News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Scientists Create Stem Cells From Adult Skin Cells

Scientists Create Stem Cells From Adult Skin Cells

Newsy (Apr. 17, 2014) The breakthrough could mean a cure for some serious diseases and even the possibility of human cloning, but it's all still a way off. Video provided by Newsy
Powered by NewsLook.com
Obama: 8 Million Healthcare Signups

Obama: 8 Million Healthcare Signups

AP (Apr. 17, 2014) President Barack Obama gave a briefing Thursday announcing 8 million people have signed up under the Affordable Care Act. He blasted continued Republican efforts to repeal the law. (April 17) Video provided by AP
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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