Taste Receptors Quotes

Humans have taste receptor cells in the gut, the voice box, the upper esophagus, but only the tongue’s receptors report to the brain.

Time to try the palatant. I raise the cup to my nose. It has no smell. I roll some over my tongue. All five kinds of taste receptors stand idle. It tastes like water spiked with strange. Not bad, just other. Not food.

She would (if she could) put her arm around the girl she'd been and try to tell her Take it easy, but the girl would not have listened. The girl had no receptors for Take it easy. And besides, "Hey Jude" was on the radio, it was her prayer, her manifesto, almost her dwelling place. She sang it everywhere. The music made her cry then; it makes her cry now. Listening to it now brings back memories so sharp they taste like blood in her mouth.

The Chinese sage Mencius made the analogy between morality and food 2,300 years ago when he wrote that “moral principles please our minds as beef and mutton and pork please our mouths.”4 In this chapter and the next two, I’ll develop the analogy that the righteous mind is like a tongue with six taste receptors. In this analogy, morality is like cuisine: it’s a cultural construction, influenced by accidents of environment and history, but it’s not so flexible that anything goes. You can’t have a cuisine based on tree bark, nor can you have one based primarily on bitter tastes. Cuisines vary, but they all must please tongues equipped with the same five taste receptors.5 Moral matrices vary, but they all must please righteous minds equipped with the same six social receptors.

she has talked to cancer patients whose taste receptors have been destroyed by radiation treatments. The situation is well beyond unpleasant. “Your body is saying, ‘It’s not food, it’s cardboard,’ and it won’t let you swallow. No matter how much you tell your brain that you need to eat to survive, you’ll gag.

Which is something to be thankful for,” says Danielle Reed, Rawson’s former colleague at Monell. Otherwise you’d be tasting things like bile and pancreatic enzymes. (Intestinal taste receptors are thought to trigger hormonal responses to molecules, such as salt and sugar, and defensive reactions—vomiting, diarrhea—to dangerous bitter items.)

she has talked to cancer patients whose taste receptors have been destroyed by radiation treatments. The situation is well beyond unpleasant. “Your body is saying, ‘It’s not food, it’s cardboard,’ and it won’t let you swallow. No matter how much you tell your brain that you need to eat to survive, you’ll gag. These people can actually die of starvation.

Rawson has an idea of what it is like to eat without perceiving tastes, because she has talked to cancer patients whose taste receptors have been destroyed by radiation treatments. The situation is well beyond unpleasant. “Your body is saying, ‘It’s not food, it’s cardboard,’ and it won’t let you swallow. No matter how much you tell your brain that you need to eat to survive, you’ll gag. These people can actually die of starvation.

People who regularly consume artificial sweeteners may find naturally sweet foods (like fruit) unappealing, and unsweet foods (like vegetables) intolerable. Artificial sweeteners may also cause insulin secretion, driving calories into fat cells and stimulating hunger.62 In addition, fat cells have been reported to contain sweet taste receptors—similar to those on the tongue. Artificial sweeteners may promote fat cell growth by stimulating these receptors or in other ways.

Here’s a thought that haunts me: What if we are designed as sensitive antennas, receptors to receive love, a longing we often mistake as a need to be impressive? What if some of the most successful people in the world got that way because their success was fueled by a misappropriated need for love? What if the people we consider to be great are actually the most broken? And what if the whole time they’re seeking applause they are missing out on true intimacy because they’ve never learned how to receive it?

I showed how the two ends of the political spectrum rely upon each foundation in different ways, or to different degrees. It appears that the left relies primarily on the Care and Fairness foundations, whereas the right uses all five. If this is true, then is the morality of the left like the food served in The True Taste restaurant? Does left-wing morality activate just one or two taste receptors, whereas right-wing morality engages a broader palate, including loyalty, authority, and sanctity? And if so, does that give conservative politicians a broader variety of ways to connect with voters?

What Heinz had done was come up with a condiment that pushed all five of these primal buttons. The taste of Heinz’s ketchup began at the tip of the tongue, where our receptors for sweet and salty first appear, moved along the sides, where sour notes seem the strongest, then hit the back of the tongue, for umami and bitter, in one long crescendo.

Carbon dioxide has its own flavor, which affects the overall taste of a drink. (At high partial pressures—which is to say, when a gas contains lots of CO2 relative to other gases—it also sets off the body’s pain receptors, called “nociceptors.” One trick almost every distiller I visited tried to play on me was to get me to stick my head into the vat during the final stages of fermentation, when the headspace—the volume of air above the liquid—is a cloud of CO2. Taking a whiff is like sticking a knitting needle up your nose. Too much of it, and you can pass out and fall right into the vat. Fun!)

Chirality matters. In the curious case of the artificial fragrance limonene, the right-handed form smells like an orange, whereas the left-handed version of this simple ring-shaped molecule smells like a lemon. The smell receptors in your nose are sensitive to chirality, so right- and left-limonene transmit slightly different signals to your brain. Taste buds are less sensitive to the differences between right- and left-handed sugars. They both taste sweet, but our body’s fine-tuned digestive system can process only the right-handed forms. The artificial sweetener tagatose, a zero-calorie left-handed sugar substitute, exploits these properties. The tragic story of thalidomide also rests on handedness. The right-handed version of this drug alleviated morning sickness in pregnant women, but the left-handed variant that inevitably tagged along caused birth defects. Today the FDA imposes strict requirements for chirally pure drugs—regulations

The cotton swab softly moved across my face, leaving a pleasant coolness behind. It swept over my forehead, down my nose, on the sides of my cheeks, and across my chin. It relaxed me and I melted. And slowly, I began to fall asleep. I considered reupping for another hour. But then I felt the burning. “Oooh,” I said, opening my eyes. “Cindy, this doesn’t feel right.” “Oh, good,” Cindy said, sounding unconcerned. “You’re starting to feel it now?” Seconds later, I was in severe pain. “Oh, I’m more feeling it,” I answered, gripping the arms of the chair until my knuckles turned white. “Well, it should stop here in a second…,” she insisted. “It’s just working its magic--” My face was melting off. “Ouch! Ow! Seriously, Cindy! Take this stuff off my face! It’s killing me!” “Oh, dear…okay, okay,” Cindy answered, quickly grabbing a soaked washcloth and quickly wiping the nuclear solution from my skin. Finally, the intense burning began to subside. “Gosh,” I said, trying to be nice. “I don’t think that’s something I want to try again.” I swallowed hard, trying to will the pain receptors to stop firing. “Hmmm,” Cindy said, perplexed. “I’m sorry it stung a little. But you’ll love it tomorrow morning when you wake up! Your skin will look so fresh and dewy.” It better, I thought as I paid Cindy for the torture and left the tiny salon. My face tingled, and not at all in a good way. And as I walked to my car, the floodgates of wedding worry opened once again: What if my dress doesn’t zip? What if the band doesn’t show up? What if the shrimp taste fishy? I don’t know how to two-step. How long is the flight to Australia? Are there tarantulas in the country? What if there are scorpions in the bed? The facial had done little to decompress me.

For unknown ages after the explosive outpouring of matter and energy of the Big Bang, the Cosmos was without form. There were no galaxies, no planets, no life. Deep, impenetrable darkness was everywhere, hydrogen atoms in the void. Here and there, denser accumulations of gas were imperceptibly growing, globes of matter were condensing-hydrogen raindrops more massive than suns. Within these globes of gas was kindled the nuclear fire latent in matter. A first generation of stars was born, flooding the Cosmos with light. There were in those times, not yet any planets to receive the light, no living creatures to admire the radiance of the heavens. Deep in the stellar furnaces, the alchemy of nuclear fusion created heavy elements from the ashes of hydrogen burning, the atomic building blocks of future planets and lifeforms. Massive stars soon exhausted their stores of nuclear fuel. Rocked by colossal explosions, they returned most of their substance back into the thin gas from which they had once condensed. Here in the dark lush clouds between the stars, new raindrops made of many elements were forming, later generation of stars being born. Nearby, smaller raindrops grew, bodies far too little to ignite the nuclear fire, droplets in the interstellar mist on their way to form planets. Among them was a small world of stone and iron, the early Earth. Congealing and warming, the Earth released methane, ammonia, water and hydrogen gases that had been trapped within, forming the primitive atmosphere and the first oceans. Starlight from the Sun bathed and warmed the primeval Earth, drove storms, generated lightning and thunder. Volcanoes overflowed with lava. These processes disrupted molecules of the primitive atmosphere; the fragments fell back together into more and more complex forms, which dissolved into the early oceans. After a while the seas achieved the consistency of a warm, dilute soup. Molecules were organized, and complex chemical reactions driven, on the surface of clay. And one day a molecule arose that quite by accident was able to make crude copies of itself out of the other molecules in the broth. As time passed, more elaborate and more accurate self replicating molecules arose. Those combinations best suited to further replication were favored by the sieve of natural selection. Those that copied better produced more copies. And the primitive oceanic broth gradually grew thin as it was consumed by and transformed into complex condensations of self replicating organic molecules. Gradually, imperceptibly, life had begun. Single-celled plants evolved, and life began generating its own food. Photosynthesis transformed the atmosphere. Sex was invented. Once free living forms bonded together to make a complex cell with specialized functions. Chemical receptors evolved, and the Cosmos could taste and smell. One celled organisms evolved into multicellular colonies, elaborating their various parts into specialized organ systems. Eyes and ears evolved, and now the Cosmos could see and hear. Plants and animals discovered that land could support life. Organisms buzzed, crawled, scuttled, lumbered, glided, flapped, shimmied, climbed and soared. Colossal beasts thundered through steaming jungles. Small creatures emerged, born live instead of in hard-shelled containers, with a fluid like the early ocean coursing through their veins. They survived by swiftness and cunning. And then, only a moment ago, some small arboreal animals scampered down from the trees. They became upright and taught themselves the use of tools, domesticated other animals, plants and fire, and devised language. The ash of stellar alchemy was now emerging into consciousness. At an ever-accelerating pace, it invented writing, cities, art and science, and sent spaceships to the planets and the stars. These are some of the things that hydrogen atoms do, given fifteen billion years of cosmic evolution.

What if we are designed as sensitive antennas, receptors to receive love, a longing we often mistake as a need to be impressive? What if some of the most successful people in the world got that way because their success was fueled by a misappropriated need for love?

the righteous mind is like a tongue with six taste receptors. Secular Western moralities are like cuisines that try to activate just one or two of these receptors—either concerns about harm and suffering, or concerns about fairness and injustice. But people have so many other powerful moral intuitions, such as those related to liberty, loyalty, authority, and sanctity.

that, instead of being fused to the skull, hangs loosely beneath the brain case. This enables the upper jaw to push forward and hyperextend open—wide enough to engulf, and crush, an adult bull elephant. As if the size and voraciousness of its feeding orifice were not enough, nature has endowed this monster with a predatory intelligence, honed by 400 million years of evolution. Six distinct senses expose every geological feature, every current, every temperature gradient … and every creature occupying its domain. The predator’s eyes contain a reflective layer of tissue situated behind the retina. When moving through the darkness of the depths, light is reflected off this layer, allowing the creature to see. In sunlight, the reflective plate is covered by a layer of pigment, which functions like a built-in pair of sunglasses. While black in normally pigmented members of the species, this particular male’s eyes are a cataract-blue—a trait found in albinos. As large as basketballs, the sight organs reflexively roll back into the skull as the creature launches its attack on its prey, protecting the eyeball from being damaged. Forward of the eyes, just beneath the snout, are a pair of directional nostrils so sensitive that they can detect one drop of blood or urine in a million gallons of water. The tongue and snout provide a sense of taste and touch, while two labyrinths within the skull function as ears. But it is two other receptor organs that make this predator the master of its liquid domain. The first of these mid-to-long-range detection systems is the lateral line, a hollow tube that runs along either flank just beneath the skin. Microscopic pores open these tubes to the sea. When another animal creates a vibration or turbulence in the water, the reverberations stimulate tiny hairs within these sensory cells that alert the predator to the source of the disturbance—miles away! Even more sensitive are the hunter’s long-range receptor cells, located along the top and underside

In the course of evolution humans have also lost huge numbers of working genes along with the abilities and traits they generated. In recent years scientists announced that human bitter-taste-receptor genes are losing their function. Identifying bitterness helps animals avoid toxic foods, precisely because so many of them taste bitter. For humans, however, an increase in meat consumption and a decrease in plant food, as well as the use of fire, which renders many toxins harmless, have meant that these bitter-taste-receptor genes are no longer maintained by natural selection. As a result they have effectively become useless.

In humans, perception is directed by the sensory nervous system. We perceive the world through sight, sound, smell, touch, and taste. But we also have other ways of sensing stimuli. Some are conscious, but many are nonconscious. For instance, you can “notice” when the temperature drops before a storm, or when the pain in your gut rises during a stomachache, or when you fall off balance while walking on rocky ground. Receptors in your body pick up on a wide range of internal stimuli, such as the amount of salt in your blood or the need to drink when thirsty. The most powerful of all human sensory abilities, however, is vision. The human body has about eleven million sensory receptors. Approximately ten million of those are dedicated to sight. Some experts estimate that half of the brain’s resources are used on vision. Given that we are more dependent on vision than on any other sense, it should come as no surprise that visual cues are the greatest catalyst of our behavior. For this reason, a small change in what you see can lead to a big shift in what you do. As a result, you can imagine how important it is to live and work in environments that are filled with productive cues and devoid of unproductive ones. Thankfully, there is good news in this respect. You don’t have to be the victim of your environment. You can also be the architect of it.

It has been postulated that a high salt intake during times of repletion causes the “salt receptors on the tongue to ‘flip’ from positive to negative…quite unlike the response of the other four basic taste sensors and thereby tends to decrease intake of salty foods.”24

People with a gene called OR6A2,34 which correlates to aldehyde receptors, tend to think cilantro (also known as coriander)35 tastes like soap or smells like “bug-infested bedclothes.”36 In fact, there’s evidence that the name coriander comes from the Greek koris (“bedbug”),37 and aldehydes similar or identical to those found in cilantro are found in soap38 and certain bug excretions, including those of bedbugs.39

Receptor neurons bundle together into cables called axons, feeding up through holes in a perforated bone just behind the eyeballs called the cribriform plate. (In a serious head injury, the skull can shift, and the lateral movement of the cribriform plate shears those axons like a knife through spaghetti. Snip! No more sense of smell.) Once through the plate, the axons connect to two projections from the brain called the olfactory bulbs. There, in blobs of neurons called glomeruli, is where the bulk of the computation gets done. Mice, known for their acute sense of smell, have just about 1,800 glomeruli—but 1,000 genes that code for olfactory receptors. That’s a lot of perceivable smells. Humans have a seemingly pathetic 370 genes for receptors, but we have 5,500 glomeruli per bulb. That’s a lot of processing power. It must be doing something. The part of the brain that integrates all this information, the olfactory cortex, also gets inputs from the limbic region and other areas that deal with emotion—the amygdala and hypothalamus, among others. Processing of smells in the brain, then, is tied to not only the chemical perception of a molecule but also how we feel about it, and how we feel in general. Every other sense in the body is, in a way, indirect. In vision, light impinges on the retina, a sheet of cells at the back of the eye that makes pigments and connects to the optic nerve. In hearing, sound (which is really just waves of changing air pressure) pushes the eardrum in and out at particular frequencies, which translate via a series of tiny bones to nerves. Touch and taste are the same. Some cell, built to do the hard work of reception, gets between the stimulus and the nerves that lead to the brain for processing. Some physical effect—air pressure, reflected photons, whatever—gets between the stimulus and the perception. It’s all a first-order derivative. Not smell, though. When we smell something, we are smelling tiny pieces of that thing that have broken off, wafted through the air, and then touched actual neurons wired to actual pieces of brain. Olfaction is direct, with nothing between the thing we’re smelling, the smell it has, and how we perceive that smell. It is our most intimate sense.

For instance, evidence suggests that palates differ between people at opposite ends of the political spectrum. Some people have a taste receptor that others do not have. For those who have it, certain green vegetables (and, one assumes, ultrahoppy or sour beers) will have a sharp, unpleasant flavor. For those without it, these vegetables taste just fine. People who take conservative positions on a range of different issues are more likely to possess this taste receptor.

the second principle of moral psychology, which is that there’s more to morality than harm and fairness. The central metaphor of these four chapters is that the righteous mind is like a tongue with six taste receptors.

• Hume’s pluralist, sentimentalist, and naturalist approach to ethics is more promising than utilitarianism or deontology for modern moral psychology. As a first step in resuming Hume’s project, we should try to identify the taste receptors of the righteous mind.

Democrats since the 1960s, in contrast, seemed narrow, too focused on helping victims and fighting for the rights of the oppressed. The Democrats offered just sugar (Care) and salt (Fairness as equality), whereas Republican morality appealed to all five taste receptors.

I didn't just feel it; I recorded each and every sensation. I can replicate each one. I will. I'll play it back plus ten for the pastardthat caused my love to fall. And before they go down, I'll wet the concrete with their brain mattter. I'll explode their marrow out of their bones and make a mess of their capillaries. I'll make a paste of their eyes, Yasmine, I promise. I'll make them bleed from their ears and turn their digestive system against them. They'll digest their own organs. I'll increase their pain receptors so that their clothes feel like sandpaper. I'll make their own breath soun d like a DC-10 is landing in their chest. I'll fill their longs with every excessive fluid in their body I can find. I'll make a decomposing mess of them, I swear I will. They'll pray to gods they don't belive in for the pain to end before I explode each taste bud in their mough and inflame their genitals with the stray parasites they immune system usually fights off.

The principal disease of abundance can be seen in habituation and jadedness (what biologists currently call dulling of receptors); Seneca: “To a sick person, honey tastes better.

…bitter taste receptors are dulled on food hotter than 95 degrees.

But a receptor community’s tastes shift rapidly. A “discovery” which was hot stuff an hour ago may now seem cold and boring as can be. Should a receptor strike a form of pay dirt whose provision has become routine, the yell it sends will lose what Cambridge University’s Dennis Bray calls its “infectability”—its ticket to fame and popularity. Other receptor molecules will ignore its “yikes, I found it” almost totally.13 In the struggle for attention, timing is everything.

The study animal of choice for taste researchers is the catfish,* simply because it has so many receptors. They are all over its skin. “Catfish are basically swimming tongues,” says Rawson. It is a useful adaptation for a limbless creature that locates food by brushing up against it; many catfish species feed by scavenging debris on the bottom of rivers.

Not all taste buds are located on the tongue. Some are found on the roof of the mouth and in the throat.… Taste receptors are also found in the lining of the intestine, suggesting that our concept of the sense of taste should include these chemical-sensing systems.

I’ve often noticed that water tastes especially delicious when I’m thirsty, and Knepper says that’s not my imagination, but the work of receptors in the back of the throat that can influence perception.

Our brains form associations between smells and tastes that in turn affect both how much we like a certain food and our bodies’ anticipated response to it (how our brain prepares the rest of the system for the calories it thinks it’s going to consume). Those associations can then be used to trigger the reward system even when the perceived reward is smaller than the actual one. Take vanilla. Vanilla isn’t actually sweet. It’s quite bitter. But in the Western world we have come to associate it with sweet foods, and so to us it signals sweetness. When we smell it, our sweet receptors go on high alert—and the food we eat tastes sweeter than it otherwise would.

In the 1970s, UCLA psychologist Eric Holman discovered that certain sweetened substances could make rodents prefer certain foods by virtue of their presence. For instance, by adding a saccharin to either a banana- or an almond-flavored solution, he was able to make rats prefer the taste of bananas or almonds, respectively, a process known as “flavor nutrient conditioning.” In recent years that work has been picked up with humans. Maltodextrin, a glucose polymer, is imperceptible to most of us. It doesn’t taste sweet. In fact, it doesn’t taste like anything. For it to activate the sweet receptors in the brain, the body must first break it down into glucose. If we mix it into another food, we don’t realize there’s a sugar present, but we still develop a preference for that flavor. In one study, people who tasted foods with maltodextrin mixed in would reliably choose the flavor that had been associated with the polymer in subsequent tests. They had been trained to prefer one food over another by a sort of sensory trickery. Imagine dusting a child’s broccoli florets with maltodextrin and transforming a disliked vegetable into a favorite.

Rinsing with glucose orally and spitting it out (that is, even without swallowing it) can cause an anticipatory release of insulin from the pancreas. This release is very small but has a large effect on lowering blood glucose during and after eating. Surprisingly, this occurs not only for sugar, but also for oral starch, such as we may find in bread, potatoes, or pasta.12 But it is not clear yet that we have starch taste receptors. We do, however, have the enzyme salivary amylase in our mouths that digests starch sufficiently to become a taste stimulus, which in turn can elicit anticipatory insulin release. Another oral response to carbohydrates involves performance enhancement. It is well known that human exercise performance is boosted when athletes eat glucose during competition

Do you know what artichokes are rich in? A little bitterness component called cynarine. It's an acid known for messing with the taste receptors on your tongue. In fact, its effects are so pronounced... ... that whatever you taste directly afterwards- even if it's just a cup of pure water!- will seem extra sweet!

Since his memory served, his sensory receptors hadn’t worked right. He had never been able to respond to any sight or sound, even if he registered it. But seeing her had felt like finding the richest shades of his favorite colors, seared across his retinas with a taste of something sweet on his tongue.