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(Anatomy) Taste: Salty Taste Linked to Birth Weight

 
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PostPosted: Sat Dec 10, 2005 10:31 am    Post subject: (Anatomy) Taste: Salty Taste Linked to Birth Weight Reply with quote






SALTY TASTE PREFERENCE LINKED TO BIRTH WEIGHT

Monell Chemical Senses Center
Press Release
Contact: Leslie Stein, PhD
Monell Center
215.898.4982
stein@monell.org

Smaller babies may have greater liking for salty taste
PHILADELPHIA (December 7, 2005) -- A new study from the Monell Chemical Senses Center may shed light on why some people like salt more than others. The results suggest that a person’s liking for salty taste may be related to how much they weighed when they were born.
In a paper published in the European Journal of Clinical Nutrition, the Monell researchers report that individual differences in salty taste acceptance by two-month old infants are inversely related to birth weight: lighter birth weight infants show greater acceptance of salt-water solutions than do babies who were heavier at birth.

According to lead author Leslie Stein, Ph.D., “The early appearance of this relationship suggests that developmental events occurring in utero may have a lasting influence on an individual’s preference for salty taste.”
A similar relationship was found in a subset of the same children at preschool age, suggesting that the relationship between salty taste preference and birth weight persists at least through early childhood, a critical time for the formation of flavor and food preferences.
By studying individual differences in liking for salty taste, scientists hope to obtain needed insights into the underlying factors driving salt preference and intake. Such information could potentially be used in programs designed to reduce salt intake, which is believed by many to contribute to the development and maintenance of high blood pressure.
Although salty taste is intrinsically appealing to humans, the basic mechanisms underlying detection and acceptance of salty taste are not well understood. According to Monell Director Gary Beauchamp, Ph.D., a co-author on the study, “The development of practical and successful methods to reduce salt intake likely will not be possible without a more thorough understanding of exactly how humans detect salty taste and the factors that modify salty taste acceptance.”

In the study, 80 healthy babies weighing at least 5.5 lb. (2.5 kg) at birth were given separate bottles containing plain water and salt water. When the amount of salt water the babies drank was compared to the amount of plain water, preference for the salt water was greater in lower-birth weight babies, while higher birth weight babies tended to reject the salty water.

When salty taste acceptance was assessed in 38 of the same children at preschool age (3-4 years), measures of salty taste acceptance were once again related to birth weight, with increased liking and preference for salty foods evident in lower birth weight children.
Stein, a biopsychologist, notes, “Because similar relationships were not found for sweet foods, the data suggest that there is a specific and enduring relationship between birth weight and salty taste acceptance. Now additional studies are needed to determine whether birth weight predicts salt preference and, even more importantly, salt intake, in older children and adults.”

###
The Monell Chemical Senses Center is an independent nonprofit basic research institute based in Philadelphia, Pennsylvania. For 35 years, Monell has been the nation’s leading research center focused on understanding the senses of smell, taste and chemical irritation: how they function and affect lives from before birth through old age. Using a multidisciplinary approach, scientists collaborate in the areas of: sensation and perception, neuroscience and molecular biology, environmental and occupational health, nutrition and appetite, health and well being, and chemical ecology and communication. For more information about Monell, please visit www.monell.org.

Citation: Stein LJ, BJ Cowart, and GK Beauchamp. Salty taste acceptance by infants and young children is related to birth weight: longitudinal analysis of infants within the normal birth weight range. European Journal of Clinical Nutrition advance online publication 23 November 2005; doi: 10.1038/sj.ejcn.1602312.

Funding: National Institute on Deafness and Other Communication Disorders, National Institutes of Health
For additional information contact: Leslie Stein, Ph.D., Monell Center, 215.898.4982, stein@monell.org
Monell Chemical Senses Center
www.monell.org

*************************************************************

Questions to explore further this topic:

What is taste?

http://faculty.washington.edu/chudler/tasty.html

Simple experiments for taste:

http://faculty.washington.edu/chudler/chtaste.html

Are smell and taste related?

http://faculty.washington.edu/chudler/taste.html

What are taste buds?

http://kidshealth.org/kid/talk/qa/taste_buds.html

Are there super tasters?

http://web.sfn.org/content/Pub.....taste.html

What is low birth wight?

http://www.marchofdimes.com/pr.....1_1153.asp

How does one prevent low birth weight?

http://www.futureofchildren.or.....c_id=79929

Is salty healthy?

http://www.hyp.ac.uk/cash/home/salt_and_health.htm
http://www.hyp.ac.uk/cash/home/how_much.htm
http://www.hyp.ac.uk/cash/info.....intake.htm

How long have humans been using salt?

http://www.sciencenewsforkids....../Note2.asp

Are there special taste messengers?

http://www.sciencenewsforkids....../Note3.asp

GAMES

http://pbskids.org/zoom/games/kitchenchemistry/


Last edited by adedios on Sat Jan 27, 2007 4:31 pm; edited 2 times in total
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PostPosted: Sun Apr 23, 2006 2:32 pm    Post subject: Sweet 'water taste' paradoxically predicts sweet taste inhib Reply with quote

Monell Chemical Senses Center
23 April 2006

Sweet 'water taste' paradoxically predicts sweet taste inhibitors

Findings provide insight into ways to manipulate human sweet taste
A scientific paradox linking artificial sweeteners such as saccharin with a sensory experience in which plain water takes on a sweet taste has guided researchers to an increased understanding of how humans detect sweet taste.
Reporting in an advance online publication in Nature, scientists from the Monell Chemical Senses Center describe how certain artificial sweeteners, including sodium saccharin and acesulfame-K, paradoxically inhibit sweet taste at high concentrations. The researchers further report that taste perception switches back to sweetness when these high concentrations are rinsed from the mouth with water, resulting in the aftertaste experience known as sweet 'water taste.'

The Nature article describes the phenomenon of sweet 'water taste' and then goes on to explain it at the level of the sweet taste receptor.

"These findings will open doors for tweaking the sweet taste receptor and finding new sweeteners and inhibitors that can be used both by food industry and in medicine," states senior author Paul A.S. Breslin, PhD, a Monell geneticist.

Lead author Veronica Galindo-Cuspinera, PhD, noted while working on a separate study that saccharin – commonly used at low concentrations as an artificial sweetener – loses its initially sweet taste when tasted at high concentrations. Galindo-Cuspinera subsequently observed that strong sweetness returned when the high concentrations of saccharin were rinsed from the mouth with water.

Working with Breslin, she next discovered that high concentrations of saccharin inhibit the sweetness of any other sweetener tasted at the same time.

Testing a variety of compounds, the researchers found that any sweetener that elicits sweet 'water taste' also acts as a sweet taste inhibitor.

To understand how sweet 'water taste' compounds could act both as a sweetener and as a sweet inhibitor, collaborators Marcel Winnig, Bernd Bufe, and Wolfgang Meyerhof of the German Institute of Human Nutrition conducted a series of molecular studies using cultured cells expressing the human sweet taste receptor.

Findings revealed that the cellular responses directly parallel the human perceptual responses.

At lower concentrations, sweeteners activate the sweet taste receptor by attaching to a high affinity binding site, leading to perception of sweetness. However, high concentrations of saccharin and acesulfame-K inhibit the cellular responses to other sweeteners by binding to a second, low-affinity inhibitory site that causes the receptor to shift from an activated to an inhibitory state. When a water rinse removes sweet taste inhibitors from the inhibitory site, the sweet receptor is re-activated and the perception of sweetness returns.

"The phenomenon of sweet water taste is the direct result of releasing the receptor from inhibition," explains Galindo-Cuspinera. "It is rare to find so complete a molecular explanation for a complex perceptual phenomenon. We can now use sweet water taste as a predictor for potential sweet inhibitors."

Sweet inhibitors are used by the food industry to counteract the undesirable high sweetness that results from replacing fats with sweet carbohydrates in reduced-fat products such as snack foods and salad dressings.

"The extremely close parallels between the behavior of the human sweet taste receptor and the perceptual phenomenon are remarkable," comments Breslin. "This two-site model should enable a more complete understanding of human sweet taste perception, leading directly to studies of how to stimulate, manipulate, enhance, inhibit, and create synergy of sweet taste."

The results will be presented at the 28th annual Meeting of the Association for Chemoreception Sciences, to be held April 26-30 in Sarasota, Florida.


###
The Monell Chemical Senses Center is an independent nonprofit basic research institute based in Philadelphia, Pennsylvania. For 35 years, Monell has been the nation's leading research center focused on understanding the senses of smell, taste and chemical irritation: how they function and affect lives from before birth through old age. Using a multidisciplinary approach, scientists collaborate in the areas of: sensation and perception, neuroscience and molecular biology, environmental and occupational health, nutrition and appetite, health and well being, and chemical ecology and communication. For more information about Monell, please visit www.monell.org.

CITATION: Galindo-Cuspinera, V., Winning, M., Bufe, B., Meyerhof, W., & Breslin, P.A.S. A TAS1R receptor-based explanation of sweet 'water taste'. Nature, advance online publication, April 23, 2006 (DOI 10.1038/nature04765).

FUNDING: National Institutes of Health and the German Science Foundation
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PostPosted: Mon Aug 07, 2006 10:40 am    Post subject: Scientists solve sour taste proteins Reply with quote

Duke University Medical Center
7 August 2006

Scientists solve sour taste proteins

DURHAM, N.C. – A team led by Duke University Medical Center researchers has discovered two proteins in the taste buds on the surface of the tongue that are responsible for detecting sour tastes.

While the scientific basis of other primary types of flavors, such as bitter and sweet, is known, this is the first study to define how humans perceive sour taste, said team senior scientist Hiroaki Matsunami, Ph.D., an assistant professor of molecular genetics and microbiology.

The identification of these proteins, called PKD1L3 and PKD2L1, could lead to ways to manipulate the perception of taste in order to fool the mouth that something sour, such as some children's medicines or health foods, tastes sweet, he said.

The team's findings appear in the online edition of the Proceedings of the National Academy of Sciences and will be published in the August 15, 2006, issue of the journal. The work was supported by the National Institutes of Health.

Mammals, including humans, can detect five primary flavors: bitter, sweet, salty, sour, and umami (known to the West as the taste of monosodium glutamate or MSG). Each taste bud on the tongue contains separate, distinct subsets of cells that specifically detect each taste -- sweet cells respond to sweet substances, bitter cells to bitter substances, and so on. Taste receptors, proteins on the surface of these cells, are responsible for detecting the "taste" of a particular food or chemical and triggering signals sent to the taste centers of the brain. In their study, the researchers used fluorescent tags to label the subsets of cells that are known to be responsible for bitter, sweet, and umami taste, as well as the subsets of cells that express PKD1L3 and PKD2L1. By "reading" the tags, they found no overlap between the subsets of cells involved in the first three tastes and the cells in which PKD1L3 and PKD2L1 are active. Matsunami said this result suggested that those proteins could be responsible for sensing either sour or salty taste.

In action, the two proteins combine to form "ion channels," porelike proteins in the membranes of taste cells, Matsunami said. These channels in turn control the flow of calcium ions, or electrically charged forms of calcium, in and out of the cells. This flow of ions essentially conditions the cell so that electrical signals can be sent to the brain in response to various stimuli.

The researchers stimulated mammalian cells expressing PDK1L3 and PKD2L1 with various taste chemicals to identify which stimuli caused the ion channels to open. To visualize the presence of calcium ions in the cell, the scientists loaded the cells with two calcium-sensitive fluorescent dyes -- one that glowed green when the calcium concentration was high, the other that glowed red when the concentration was low.

When they added sour-tasting acids to the cells, the ion channels went from closed to open, enabling calcium ions to flow in, increasing their concentration within the cell and changing the cells from red to green, Matsunami said. The channels remained closed when confronted with salt, sweeteners, or bitter solutions. The increased concentration of calcium in the cell may then trigger the signal that the brain eventually perceives as sour taste, he said.

Matsunami said he plans to use this finding to screen for chemicals that can block the function of these sour taste cells. The research also could lead to a better understanding of how the sense of taste functions neurologically, he said. "We still do not know what is happening in the brain -- that is, exactly how the brain would interpret the signals coming from the tongue to tell the difference between lemons and lemonade," Matsunami said. Future experiments using live animals as test models will be needed to answer remaining questions about taste sensation, he said.


###
Other researchers who participated in the study include Yoshiro Ishimaru, Momoka Kubota and Hanyi Zhuang of Duke; Hitoshi Inada and Mokoto Tominaga of the National Institute of Natural Sciences, Okazaki, Japan.
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PostPosted: Sat Aug 26, 2006 11:43 am    Post subject: A Sour Taste in Your Mouth Reply with quote

A Sour Taste in Your Mouth
30 August 2006

Emily Sohn

Think of all the amazing things that your tongue does for you. Specialized cells on your tongue, for example, give you the power to enjoy (and gag at) the spices and other flavors of the world's cuisines.
For years, scientists have been investigating the cells that allow us to detect five distinct tastes: salty, sweet, bitter, sour, and umami. Umami describes the taste of a substance called monosodium glutamate (MSG). So far, sweet, bitter, and umami are pretty well understood. The other two have remained mysterious.

For the full article:

http://www.sciencenewsforkids....../Note3.asp
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PostPosted: Tue Aug 29, 2006 2:35 pm    Post subject: The Tongue Map: Tasteless Myth Debunked Reply with quote

The Tongue Map: Tasteless Myth Debunked

By Christopher Wanjek
LiveScience’s Bad Medicine Columnist
posted: 29 August 2006
08:19 am ET



The notion that the tongue is mapped into four areas—sweet, sour, salty and bitter—is wrong. There are five basic tastes identified so far, and the entire tongue can sense all of these tastes more or less equally.

As reported in the journal Nature this month, scientists have identified a protein that detects sour taste on the tongue. This is a rather important protein, for it enables us and other mammals to recognize spoiled or unripe food. The finding has been hailed as a minor breakthrough in identifying taste mechanisms, involving years of research with genetically engineered mice.

For the full article:

http://www.livescience.com/hum.....ongue.html
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PostPosted: Mon Sep 18, 2006 1:54 pm    Post subject: Fruit flies have something to tell you about caffeine Reply with quote

Johns Hopkins Medical Institutions
18 September 2006

Psst! Coffee drinkers: Fruit flies have something to tell you about caffeine

In their hunt for genes and proteins that explain how animals discern bitter from sweet, a team of Johns Hopkins researchers began by testing whether mutant fruit flies prefer eating sugar over sugar laced with caffeine. Using a simple behavioral test, the researchers discovered that a single protein missing from the fly-equivalent of our taste buds caused them to ignore caffeine's taste and consume the caffeine as if it were not there.

"No, you won't see jittery Drosophila flitting past your bananas to slurp your morning java anytime soon," says Craig Montell, Ph.D., a professor of biological chemistry in the Institute of Basic Biomedical Sciences at Hopkins. "The bottom line is that our mutant flies willingly drink caffeine-laced liquids and foods because they can't taste its bitterness -- their taste receptor cells don't detect it."

The Hopkins flies, genetically mutated to lack a certain taste receptor protein, have been the focus of studies to sort out how animals taste and why we like the taste of some things but are turned off by the taste of others.

By color-coding sweet and bitter substances eaten by fruit flies and examining the coloring that shows up in their translucent bellies, the Hopkins team hoped to learn whether flies missing a specific "taste-receptor" protein changed their taste preferences.

"Normally," Montell explains, "when given the choice between sweet and bitter substances, flies avoid caffeine and other bitter-tasting chemicals. But flies missing this particular taste-receptor protein, called Gr66a, consume caffeine because their taste-receptor cells don't fire in response to it."

The discovery, which is the first ever example of a protein required for both caffeine tasting and caffeine-induced behavior, will be published Sept. 19 in Current Biology.

For the study, Montell and his colleagues kept 50 fruit flies away from food overnight and for breakfast gave the starved flies 90 minutes to eat as much as they wanted of either or both of two concoctions: a blue-colored mixture of sugar and agar and a red-colored mixture of caffeine, sugar and agar. The researchers then flipped the flies onto their backs and looked at the color of their bellies to see what they ate - blue indicating a preference for eating sugar, red indicating a preference for bitter caffeine, and purple indicating no preference.

Flies missing the critical taste receptor protein Gr66a consumed the bitter caffeine solution to the same extent as the sugar-only solution. Montell and colleagues conclude that Gr66a is crucial for the normal caffeine avoidance behavior and without it, flies are seemingly indifferent to the bitter taste.

The researchers went on to examine whether this indifference to bitter was due to the taste nerves on the fly's "tongue" or some malfunction in the fly's brain. Chemical stimulants trigger taste receptor cells to send an electrical current to the brain where the information is processed and often leads to a change in behavior, such as the decision to eat or avoid.

With fine tools, the research team recorded electrical currents in those cells known to contain the Gr66a caffeine taste receptor in the fly's equivalent of the taste buds - dubbed the taste bristles.

Applying sugar to the taste bristles of normal flies, or to mutant flies missing the Gr66a protein, causes the neurons to produce electrical current "spikes" at a frequency of about 20 spikes per second. Other bitter compounds like quinine generated electrical current spikes at about the same frequency in the mutants.

Only flies missing the Gr66a taste receptor protein were unable to generate any current spikes when given caffeine. "This is a clear demonstration that Gr66a is functioning in the taste receptor cells and is not a 'general sensor' for bitter compounds, but is required more specifically for the caffeine response," says Montell.

"This indicates that flies have different receptors for the response to other types of bitter compounds," he says.

"We also tested whether the flies avoided the related bitter compounds found in tea and cocoa -- chocolate -- and found that Gr66a also is required for the response to the compound in tea, but not for the one in chocolate," he says.

Fruit flies often are used as experimental organisms because they grow quickly and are easy to manipulate genetically. Now that Montell and his colleagues have a mutant fly that is unable to taste caffeine, they hope to further examine the other genes and molecules involved in the caffeine response and better understand the biochemistry behind caffeine-induced behavior in other organisms, namely humans.


###
The researchers were funded by the Polycystic Kidney Disease Foundation and the National Institute of Deafness and Communicative Disorders of the National Institutes of Health.

Authors on this paper: Seok Jun Moon, Michael Köttgen, Yuchen Jiao, Hong Xu and Montell, all of Hopkins.

On the Web:

http://www.hopkinsmedicine.org/cmontell/
http://www.hopkinsmedicine.org/ibbs/index.html
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PostPosted: Tue Sep 19, 2006 9:42 pm    Post subject: Researchers examine why food tastes bad to chemotherapy reci Reply with quote

Virginia Tech
19 September 2006

Researchers examine why food tastes bad to chemotherapy recipients

Blacksburg, Va. –– About two million cancer patients currently receiving certain drug therapies and chemotherapy find foods and beverages to have a foul metallic flavor, according to a medical study. In general, more than 40 percent of hospitalized patients suffer from malnutrition due to taste and smell dysfunction.

"Unfortunately, these problems that impact nutrition and quality of life are underestimated and understudied by oncologists," said Andrea Dietrich, Virginia Tech professor of civil and environmental engineering (CEE).

Dietrich believes there are two components to the metallic flavor –– the taste of metal ions on the tongue and the production of metal-catalyzed odors in the mouth that create a retro-nasal effect. "I am attempting to gain a better understanding of the metallic sensation, its prevention, and application to human health," Dietrich said.

Along with two of her university colleagues, Susan E. Duncan, professor of food science and technology, and YongWoo Lee, an assistant professor in the biomedical sciences and pathology department and a member of the Virginia Tech-Wake Forest University School of Biomedical Engineering and Sciences, Dietrich is the recipient of a $200,000 grant from the Institute of Public Health and Water Research (IPWR) to examine the problems of foul flavored water. The interdisciplinary investigative team combines proficiency in food oxidation and off-flavors, water chemistry, cell biology, and human perception.

Dietrich, the principal investigator on the project, is an expert on water quality and treatment, as well as its taste and odor assessment. In fact there are some 33 identified flavors of drinking water acknowledged by the American Water Works Association and Research Foundation (AwwaRF). They range in description from "wet paper" to "crushed grass" to "peaty" to "plastic."

Several years ago, AwwaRF sponsored Dietrich to travel around the U.S. to educate utility staff and managers on how to use sensory analysis to detect changes in water quality. She is also a co-developer of three odor-testing methods for the daily monitoring of raw and untreated water.

Now she is hoping to work with medical personnel as she, Duncan, and Lee compare the sensory thresholds, recommended nutritional levels, and adverse health effect levels of iron and copper in water, and their relationship to health-based problems such as persistent metallic tastes of patients receiving chemotherapy.

They hope to identify the cause of the metallic flavor in the mouth when drinking water contains metal ions, specifically iron and copper. Their research will also evaluate the use of antioxidants to prevent the metallic flavor production. "If we can discover the cause of the production of metallic flavor, then preventive methods can be taken accordingly," Dietrich said.

In correct amounts, metals in drinking water are actually important sources of micronutrients in the human diet. In fact, iron and copper are commonly found in drinking water, and they can be an important source of these mircronutrients. However, there are thresholds. If ingested at higher concentrations, greater than three milligrams per liter, iron and copper "may cause nausea, vomiting, diarrhea, kidney and liver damage," Dietrich explained.

Some tests will be done with human volunteers to determine reactions of volatile compounds in the mouth. Since saliva contains proteins and enzymes, it may have some effect in enhancing the metallic flavor. They will also use in-vitro experiments in order to conduct experiments at higher concentrations without endangering anyone, Dietrich added.

Perception of taste and odor is very complex, and like nutritional needs, varies depending on age, gender, race, health status, prior exposure and experience.

Two graduate CEE students, Pinar Omur-Ozbek and Jose Cerrato, both of Blacksburg, Va., will work on this project.
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PostPosted: Mon Oct 30, 2006 8:05 pm    Post subject: Tastes great! Study shows brain's response to pleasing Reply with quote

University of Michigan Health System
30 October 2006

Tastes great! Study shows brain's response to pleasing -- and changing -- tastes
Study may help understanding of pleasure response, and how it can go wrong
ANN ARBOR, Mich. -- We all have tastes we love, and tastes we hate. And yet, our "taste" for certain flavors and foods can change over time, as we get older or we get tired of eating the same old thing.

Now, a new University of Michigan study gives new evidence about what's going on in the brain when we taste something we like, or develop a liking for something we once hated.

And although the study used rats instead of people, it has direct implications for understanding the way we perceive pleasure – and the reasons why some people develop problems, such as drug abuse, depression or anorexia, that knock their pleasure response off balance.

In a new paper in the November issue of the Journal of Neurophysiology, U-M neuroscientists and psychologists report the findings from direct monitoring of an area of the brain known as the ventral pallidum. Located deep in the brain, it's a kind of traffic center for signals from different areas of the brain that process tastes and pleasurable sensations.

The researchers were able to track the activity of brain cells in that area while the rats received water, salt water and sugar water directly into their mouths. They also recorded how the rats behaved while they tasted those different solutions, including signs that they liked or disliked the tastes. And, they repeated the tests when the rats had been treated with drugs that greatly reduced their bodies' salt levels.

At first, the rats all behaved negatively after tasting a strong salt-water solution, compared to the water or sugar water. Their ventral pallidum brain activity was also much lower in response to the salt water.

But when the researchers put the rats into a salt-deprived state using a combination of diet and hormones that cause the body to get rid of salt, the picture changed. Suddenly, the rats' brain activity rose as high when they received the salt water as it had when they received sugar water. The effect lasted for a while after the rats' bodies returned to normal salt levels, but soon enough it wore off.

"We converted something that wasn't pleasing to something that suddenly became pleasurable, and when we did that the neurons we were studying switched their response," says senior author J. Wayne Aldridge, Ph.D., a research associate professor in the Department of Neurology at the U-M Medical School. "Pleasure has traditionally been one of the hardest problems for neuroscience to measure, but these results shed light on how it is represented in brain activity."

The study was designed so that the signals from the ventral pallidum were only related to the "liking" – or disliking – of the taste, and not to a salt-seeking drive or movement. The ventral pallidum is part of the limbic system of the brain, which is involved in motor-muscle control as well as pleasure and reward.

In an accompanying editorial, University of North Carolina researchers Robert Wheeler and Regina Carelli call the study "elegant" and the results a "profound step" toward understanding the nature of pleasure itself, rather than the behaviors and actions triggered by it.

Aldridge collaborated on the study with former U-M Psychology graduate student Amy Tindell, Ph.D., and with Kent Berridge, Ph.D., a professor in the Department of Psychology in the College of Literature, Science, and the Arts.

"This finding reveals a type of brain Morse code for pleasure," says Berridge. "The faster these neurons fire, the more pleasant the taste seems to become. The hardest test for a pleasure code is whether the brain signal can track the change from nasty to nice. The amazing fact is that these neurons pass that test."

Aldridge notes that an analogous effect occurs in everyday human life, when a formerly favorite food becomes less attractive after we have over-indulged in that food.

"Moment by moment, this low-level information processing in the brain helps us react to what we like or don't like," he says. "These neurons respond to a taste as pleasurable, or as not pleasurable."

But research on how these neurons fire to signal pleasure is important for more than just curiosity's sake, he adds. The ventral pallidum is an important brain region for both pleasure and craving. If firing patterns go wrong in ventral pallidum, it could possibly contribute to eating disorders, anorexia and drug addiction.

Eventually, activation in the ventral pallidum in response to pleasurable tastes could also be useful in brain-mapping techniques in humans. All in all, Aldridge says, the new paper is "a really good example of how animal experiments help us understand the human brain. If we can understand how the brain generates normal pleasures, we may have a new focus for effective treatments in people who don't experience normal pleasure."
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PostPosted: Tue Nov 21, 2006 10:42 am    Post subject: Doctors Say How We Taste Affects Health Reply with quote

Doctors Say How We Taste Affects Health

By Lauran Neergaard
Associated Press
posted: 20 November 2006
06:02 pm ET



WASHINGTON (AP) -- Woe to those who have a cold on Thursday. If you can't smell the roasting turkey, it just won't taste as good.

And if you think the brussels sprouts are bitter, well, blame how many taste buds you were born with, not the chef.

But never fear: Even after you're pleasantly stuffed from second helpings, there's a little spot deep in your brain that still gives a "Wow!'' for pumpkin pie.

How we taste is pretty complicated, an interaction of the tongue, the nose, psychological cues and exposure to different foods.

But ultimately, we taste with our brains.


For the full article:

http://www.livescience.com/hum.....ealth.html
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PostPosted: Thu Nov 23, 2006 7:58 am    Post subject: New Insight into People Who Taste Words Reply with quote

New Insight into People Who Taste Words

By Ker Than
LiveScience Staff Writer
posted: 22 November 2006
01:01 pm ET

For most of us, the boundaries between our bodily senses are clear-cut and rigid. But for a few rare individuals, the demarcation between vision and hearing, or between taste and touch, are less solid, with one bleeding into the other.

These people have a condition called "synesthesia," in which two or more of the senses are crossed. Some see colors when listening to music, while others associate tastes with shapes or words with colors.

A very small number of synesthetes can "taste" words.

A new study finds that individuals with this last form of synesthesia—called "lexical-gustatory" synesthesia—can taste a word before they ever speak it, and that the word's meaning, not its sound or spelling, is what triggers this taste sensation.

The finding, detailed in the Nov. 23 issue of the journal Nature, could help scientists unravel how perception works in the rest of us.

For the full article:

http://www.livescience.com/hum.....astes.html
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PostPosted: Wed Dec 06, 2006 7:15 am    Post subject: Penn researchers discover initial steps in the development o Reply with quote

University of Pennsylvania School of Medicine
5 December 2006

Penn researchers discover initial steps in the development of taste
Wnt protein required for taste buds and wiring of taste signals to the brain


(PHILADELPHIA) -- Of the five senses, taste is one of the least understood, but now researchers at the University of Pennsylvania School of Medicine have come one step closer to understanding how the sense of taste develops. They have pinpointed a molecular pathway that regulates the development of taste buds. Using genetically engineered mice, they discovered that a signaling pathway activated by small proteins called Wnts is required for initiating taste-bud formation. They have also determined that Wnt proteins are required for hooking up the wiring of taste signals to the brain.

Senior author Sarah E. Millar, PhD, Associate Professor in the Departments of Dermatology and Cell and Developmental Biology, Penn postdoctoral fellow Fei Liu, PhD, and colleagues report their findings in the most recent online issue of Nature Genetics. "The developmental biology of taste is underexplored," says Millar of her team's impetus for the study.

The researchers demonstrated that blocking the action of Wnt proteins in surface cells of the developing tongue prevents taste-bud formation, while stimulating Wnt activity causes the formation of excessive numbers of enlarged taste papillae that are able to attract taste-related nerve fibers. This study represents the first genetic analysis of taste-organ initiation in mammals. While these studies were performed in mice, the researchers believe that their findings will also hold true for understanding the basis of taste-bud development in humans.

Taste buds are the sensory organs that transmit chemical stimuli from food and other sources to nerve cells, which convey these signals to the taste centers in the brain. Taste buds sit in the small bumps in the surface and sides of the tongue called papillae.

The signaling pathway activated by Wnt proteins is critical to the development of many organ systems, and its inappropriate activation causes human diseases including colon cancer. In previous studies, Millar and colleagues have shown that this pathway is essential for initiating the formation of hair follicles and mammary glands in mice.

The sites of Wnt signaling are easily visualized in specially engineered transgenic mice, using an enzymatic assay. "We noticed in the tongue that there was this beautiful pattern of blue spots that correspond to the developing taste papillae," says Millar. "This connected the Wnt pathway to their development."

In the present study, the researchers found that in mice in which the actions of Wnt proteins were blocked, taste papilla buds completely failed to develop. Conversely, in mice in which Wnt signaling was over activated, their tongues were covered with many and large papillae and taste buds.

"Unlike most surface epithelial cells, taste buds have characteristics of neurons as well as skin. Like other types of epithelial cells they turn over and regenerate, but they also express chemoreceptors and make synapses with neurons," explains Millar. The group studied how developing taste buds become wired into the nervous system. In early tongue development, neurons enter the tongue epithelium and make synapses with taste bud cells. This study confirmed that taste buds produce signals that attract nerve fibers to them. When taste-bud development was prevented by blocking Wnt signaling, the nerve fibers did not enter the tongue epithelium.

"They don't know where to go on their own," she says.

Millar also mentions that by now understanding the basis for the initiation of taste-papilla formation, the evolution and difference between species in the numbers and patterns of taste buds can be more fully explored. All animals that taste have taste buds, but there are differences, for example humans have more (around 200) taste papillae than mice, and they are arranged in a different pattern.

Future research directions will include determining whether Wnt signaling is also important for the periodic regeneration of taste buds from taste-bud stem cells that occurs throughout life in adult animals. Taste-bud regeneration can be affected by chemotherapy, so understanding this process will have important implications for patient care.

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The research was supported by the National Institutes of Health. In addition to Millar and Liu, co-authors on the paper are: Natalie Gallant, Seshamma T. Reddy, and Thomas Andl, from Penn; Shoba Thirumangalathu and Linda Barlow from the University of Colorado Health Sciences Center; Steven Yang and Andrzej A. Dlugosz from the University of Michigan; Cristi L. Stoick-Cooper and Randall T. Moon from the Howard Hughes Medical Institute and University of Washington; and Makoto M. Taketo from Kyoto University.

For this release and related image, go to: http://www.uphs.upenn.edu/news/

PENN Medicine is a $2.9 billion enterprise dedicated to the related missions of medical education, biomedical research, and high-quality patient care. PENN Medicine consists of the University of Pennsylvania School of Medicine (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System.

Penn's School of Medicine is ranked #2 in the nation for receipt of NIH research funds; and ranked #3 in the nation in U.S. News & World Report's most recent ranking of top research-oriented medical schools. Supporting 1,400 fulltime faculty and 700 students, the School of Medicine is recognized worldwide for its superior education and training of the next generation of physician-scientists and leaders of academic medicine.

The University of Pennsylvania Health System includes three hospitals, all of which have received numerous national patient-care honors (Hospital of the University of Pennsylvania; Pennsylvania Hospital, the nation's first hospital; and Penn Presbyterian Medical Center); a faculty practice plan; a primary-care provider network; two multispecialty satellite facilities; and home care and hospice.
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PostPosted: Tue Feb 13, 2007 8:12 am    Post subject: More than meets the tongue Reply with quote

University of Chicago Press Journals
12 February 2007

More than meets the tongue

The color of a drink can fool the taste buds into thinking it is sweeter
Does orange juice taste sweeter if it's a brighter orange? A new study in the March issue of the Journal of Consumer Research finds that the color of a drink can influence how we think it tastes. In fact, the researchers found that color was more of an influence on how taste was perceived than quality or price information.

"Perceptual discrimination is fundamental to rational choice in many product categories yet rarely examined in consumer research," write JoAndrea Hoegg (University of British Columbia) and Joseph W. Alba (University of Florida). "The present research investigates discrimination as it pertains to consumers' ability to identify difference—or the lack thereof—among gustatory stimuli."

Hoegg and Alba are the first to look at how individual attributes -- such as color, price, or brand -- can affect which products we prefer. The researchers manipulated orange juice by changing color (with food coloring), sweetness (with sugar), or by labeling the cups with brand and quality information. They found that though brand name influenced people's preferences for one cup of juice over another, labeling one cup a premium brand and the other an inexpensive store brand had no effect on perceptions of taste.

In contrast, the tint of the orange juice had a huge effect on the taster's perceptions of taste. As the authors put it: "Color dominated taste."

Given two cups of the same Tropicana orange juice, with one cup darkened with food coloring, the members of the researcher's sample group perceived differences in taste that did not exist. However, when given two cups of orange juice that were the same color, with one cup sweetened with sugar, the same people failed to perceive taste differences.

"It seems unlikely that our consumers deliberately eschewed taste for color as a basis for discrimination," write the authors. "Moreover, our consumers succumbed to the influence of color but were less influenced by the powerful lure of brand and price information."

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Hoegg, JoAndrea, and Joseph W. Alba. "Taste Perception: More Than Meets the Tongue," Journal of Consumer Research: March 2007.
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PostPosted: Thu Jul 12, 2007 2:12 pm    Post subject: Sour taste make you pucker? It may be in your genes Reply with quote

Monell Chemical Senses Center
11 July 2007

Sour taste make you pucker? It may be in your genes

Twin study indicates sensitivity to sour taste is highly inherited
Philadelphia (June 11, 2007) -- Scientists at the Monell Chemical Senses Center report that genes play a large role in determining individual differences in sour taste perception. The findings may help researchers identify the still-elusive taste receptor that detects sourness in foods and beverages, just as recent gene studies helped uncover receptors for sweet and bitter taste.

Scientists have long known that sour taste is stimulated by acids in foods and beverages. In fact, the word acid is derived from the Latin ‘acidus,’ meaning sour. However, we still do not completely understand how the taste system is able to detect and translate acidic molecules on the tongue into a neural signal that the brain perceives as ‘sour.’

“Demonstrating a genetic component to individual differences in sour taste is the first step in pinpointing the genes that determine sensitivity. The products of those genes, in turn, are likely to be involved in sour taste perception,” says study lead author Paul M. Wise, PhD, a Monell sensory psychologist.

In the study, published online in advance of print in the journal Chemical Senses, researchers tested 74 pairs of monozygotic (MZ, identical) twins and 35 pairs of dizygotic (DZ, fraternal) twins to determine the lowest concentration needed for each twin to correctly identify a citric acid solution as ‘sour.’

Because MZ twins have nearly identical genes while DZ twins share only about 50% of their genes, more similar responses in MZ than DZ pairs suggests that genes help determine sensitivity to the taste in question.

Responses were compared within the twin pairs, and then entered into a computer model to determine the relative contributions of genetic and environmental influences on sour taste sensitivity.

The models estimated that genes played a more important role than environment in determining individual differences in sour taste sensitivity, accounting for 53 percent of the variation.

The finding that genes influence sour taste perception suggest that genetic analyses could potentially help identify sour receptors. Future studies will evaluate possible receptors by determining whether individual differences in genes for these structures – such as the recently-discovered PKD ion channel – are correlated with individual differences in sensitivity to sourness. For any given candidate receptor, a strong association of genetic with perceptual variation would support the likelihood that the receptor detects sour taste.

The findings, in conjunction with previous work on sweet, bitter, and umami (savory) taste, suggest that people differ in how they perceive the taste of foods, and that these differences are determined in part by their taste genes. So someone who inherited a high sensitivity to sour taste may find foods containing lemons or vinegar off-putting, whereas the same foods may be better accepted by a person whose genes make them less sensitive.

Wise comments, “These taste perceptions presumably evolved because they have a significant impact on food choice and therefore nutrition. If we can understand how and why people differ in their taste perception, we might eventually be able to manipulate the taste of individual diets to help encourage healthy eating.”

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Also contributing to the work were Danielle R. Reed and Paul A.S. Breslin of Monell and Jonathan L. Hansen from the Queensland Institute of Medical Research in Brisbane, Australia.

The Monell Chemical Senses Center is a nonprofit basic research institute based in Philadelphia, Pennsylvania. For 39 years, Monell has been the nation’s leading research center focused on understanding the senses of smell, taste and chemical irritation: how they function and affect lives from before birth through old age. Using a multidisciplinary approach, scientists collaborate in the areas of: sensation and perception, neuroscience and molecular biology, environmental and occupational health, nutrition and appetite, health and well being, and chemical ecology and communication. For more information about Monell, please visit www.monell.org
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PostPosted: Sat Jul 21, 2007 10:25 am    Post subject: Sour Genes, Yes—Salty Genes, No Reply with quote

Week of July 21, 2007; Vol. 172, No. 3

Sour Genes, Yes—Salty Genes, No
Janet Raloff

Some people abhor broccoli, complaining about its intensely bitter taste. Others (myself included) find broccoli's flavor interesting and pleasing—decidedly, not bitter. What leads to our differing culinary opinions is the possession of, or lack of, (in my case, evidently) genes conferring a super sensitivity to bitter taste. Science has recognized such genetic differences for at least a decade.

For the full article:

http://sciencenews.org/articles/20070721/food.asp
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PostPosted: Fri Nov 30, 2007 4:17 pm    Post subject: What Makes Food Taste Sweet? Reply with quote

What Makes Food Taste Sweet?
November 30, 2007
Corey Binns

A spoonful of sugar makes the medicine go down with some fancy tricks on your tongue, and your eyes.

Taste buds are clusters of up to 100 cells. Nerve fibers connect each bud to the brain.

Sugars, and some synthetic sweeteners, interact with two types of taste receptors on the tongue, according to a 2005 study published in the journal Current Biology.

For the full article and links:

http://www.livescience.com/mys.....sweet.html
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