Taste buds have evolved to fill a wide variety of functions

Taste buds do more than let you experience your favorite food. These peripheral organs can sense the chemical makeup, potential toxicity, and fleeting experience of flavor, giving the body a chance to respond to undesirable chemicals or tell the brain that you should reach for another scoop.

A timeline of the science of taste discoveries

The tongue is made up of four types of papillae—elevated, nipple-like projections that give the organ its rough texture. In the early 1900s, initial research into the tongue's varying taste sensitivity led to a misleading map of the tongue and its taste regions. Over the decades, researchers fleshed out five distinct tastes (and more recently, a sixth).

These cells 'taste' danger, trigger immune responses

Taste receptor-coated tuft cells are found throughout the body, where they communicate with and take part in a growing list of biological processes. In the intestines, these taste receptor-studded cells can sense byproducts of parasite metabolisms. This causes the taste receptors to release chemicals that alert the immune system, order nearby goblet cells to produce mucus, and trigger muscle contractions in attempts to launch the parasites from the intestines.

Our sense of smell affects what foods taste like and how we perceive it

Scent stimulates our olfactory sensor neurons high in the nasal cavity, and the brain attaches labels to those scents. But when we eat, chemicals from the foods travel from our mouths and throat to those neurons. We have roughly 400 odor receptors, and they can be used to decipher more than 10,000 different odors (or more than one trillion by some calculations), including the nuances of different foods.

How texture affects taste

Texture is the brain's interpretation of several sensations, including pressure, as registered by our teeth, tongue, and finger tips, and sound, as recorded by our ears. Texture also speaks to food particle sizes—smaller than 35 microns contributes to the sensation of creamy—and the balance between flavor and mouth time, such as the crunch of a crispy chip or the bounce of a chewy caramel.

Humans have taste receptors throughout the body, including in the testes and lungs, but we don't taste what they detect because those areas lack taste buds.

Octopuses have taste receptors along their tentacles

Octopus suction cups are filled with modified sensory receptors that can bind with a greater variety of materials and transport a wider array of information, such as flavor, from tactile stimuli. These structures allow the animal to search for food as it crawls the ocean floor.

Many parts of the body, including the testicles, have bitter, sweet, and umami receptors

Taste receptors—the tiny cells that report the chemical makeup of external stimuli to the brain—in the testicles don't "taste" in the same way as the gustatory ones you use to determine if there's enough sugar in your tea. Research suggests that these "teste" receptors can sense bitter, sweet, and umami compounds and use that chemical input to control physiological processes or (literally) change direction. (Some users may experience a paywall.)

Humans may be able to distinguish more than one trillion scents

That's according to one estimate published in 2014. This figure far exceeds earlier estimates of a human smelling ceiling around 10,000 odors. The newer figure is derived from experiments in which volunteers agreed to sniff varying scents. Researchers mixed odor components and had volunteers sniff the brews to detect subtle scent differences. (Some users may experience a paywall.)

How our sense of taste evolves as we age

Kids are hardwired to prefer sweets over greens, with sweetness a shorthand for calorie-rich and bitter flavor warning of potentially noxious plants. This holds true even in the womb, where fetuses have been seen via ultrasound scans grimacing as their hosts consume kale capsules. As they age into double digits and beyond, their taste cells and sense of smell diminish, leading to broader and less sensitive palates.

How bitter taste receptors help guard against infection

Receptors for "bitter" tastes evolved to detect potentially harmful plant chemicals, such as nicotine. The receptors also trigger bacteria-fighting responses, including waving hairlike projections to bat away bacteria, ordering the release of bacteria-killing nitric oxide, and calling for antimicrobial protein reinforcements.

The idea of a tongue map has been discredited, but taste sensitivity can vary across the tongue.

The research that led to sour

Scientists are trying to figure out if there are unique receptors that respond to the molecules that make up flavors we associate with calcium, blood, batteries, and other items that often escape dinner menus. Taste researcher Dr. Danielle Reed says the minimum evidence for a taste category typically involves identifying dedicated receptors and then removing them to show the taste vanishes.

Breaking down various tongue disorders, from infections to genetics

Taste is one of our fundamental senses, but can be impeded by a wide variety of conditions including glossitis, angioedema, and black hairy tongue. Most are characterized by their color, shape, and sometimes change in function. Causes range from vitamin or mineral deficiencies to fluid accumulation, fungal infection, or more.

How the five senses share information with each other

The human body depends on information from the five sensory organs—the eyes, ears, nose, tongue, and skin—to react to the world around it. Each of these organs, in its own way, relies on complex circuitry to send signals back to the central nervous system.

Cats have a mutation that prevents them from tasting sweetness, and goldfish rank among the world's supertasters.

What is it like to be a bee?

Scientists have long known the intimate features of bee anatomy: six limbs, five eyes, lots of hair, a long, tasteless tube -like tongue, and wings that stroke close to 12,000 times a minute. But getting inside the mind or consciousness of a...

Babies taste food in the womb via amniotic fluid, and it may influence future taste buds.

The body's master clock has 20,000 neurons

The suprachiasmatic nucleus, the master clock in mammals, has 20,000 neurons that help maintain the light-dark cycle in the body. Among its jobs: It receives light input information from the retina and then signals peripheral body clocks to act on this information, driving everything from body temperature to hunger.

When humans perceive touch, the information is sent to the thalamus and then to the primary somatosensory cortex, the part of the brain that receives sensory input.

A dog's central sniffing organ is many times bigger than a human's

The olfactory epithelium, located high up within the human nose, is home to millions of olfactory neurons. A dog's olfactory epithelium is much larger—and has more neurons—than a human's, which helps to explain the animal's superior sniffing ability.

Meet the 12 cranial nerves

Your cranial nerves are a set of 12 paired nerves in your brain. They help your brain and body communicate senses, movement or both.

Individuals with synesthesia experience involuntarily overlapping sensations

Tasting words or seeing colors in music results from the brain retaining extrasensory connections from infancy. While most lose these neural pathways during development, about 4% of people are synesthetes, maintaining them without realizing it's unusual.

The tongue evolved in animals roughly 350 million years ago

Creatures like fish rely on suction to consume food, flexing their gills to create water currents that vacuum up their meals. The evolution of the tongue enabled vertebrates to completely cut ties with the sea, moving onto land where they could sample new foods and ways to eat them.

A dog's nose can be up to 100,000 times more sensitive than a human's, and each possesses a secondary organ for smelling, which helps learn about other dogs when they sniff each other's butts.

A Venus flytrap's hairs convert sensory touch into electrical signals

A stretch-activated ion channel called DmMSL10 acts as an amplifier, converting grazing contact into a strong impulse that the plant uses to react and close its jaw. To distinguish prey from raindrops or other stimuli, the jaw only closes when the hairs are touched twice in quick succession.

At any given time, there are an estimated 10 quintillion individual insects alive on Earth.

Ammonium may be the sixth basic taste

Researchers have proposed various candidates for the sixth official taste, including "fat." But research published in 2023 posits that ammonium should be considered the sixth taste since they found humans can apparently detect ammonium chloride, which the scientists describe as "bitter, salty, and a little sour." Detecting ammonia could be a survival mechanism to help detect when certain foods, including seafood, are no longer safe to eat. The work hinged on experiments with human cells exposed to ammonium chloride as well as rodent research.

Scientists have unraveled new details about which nerve cells control goose bumps

Research in 2016 revealed that at least eight different types of neurons are associated with the sympathetic nervous system. One finding revealed that goose bumps and nipple erection are caused by neurons specialized to regulate these specific functions by controlling the erectile muscles in those tissues.

Tetrachromacy allows humans to observe 10 times the normal amount of colors

Resulting from a mutation on the X chromosome, the rare genetic condition causes individuals to possess an additional type of photoreceptor cell, typically sensitive to the orange range, located between the standard red and green cones. This enables the perception of approximately 100 million colors.

Explore an interactive 3D model of the brain

The brain contains about 86 billion neurons—nervous system cells—and controls vital bodily functions via electrochemical signals. Neurons form circuits through axons, and different brain regions use these circuits to perform specific tasks.

The three smallest bones in the human body—the malleus, incus, and stapes—amplify the vibrations of sound waves by almost 20 times to help enable hearing.

How humans digest food

Every day, the average human eats close to six pounds of food—all of which must be processed by the digestive system. Ten organs collaborate to transform food that the mouth chews into the energy needed to stay alive. (Stretched out, these organs...

How brain cells carry information

At any moment, there is an electrical storm coursing through your body. Discover how chemical reactions create an electric current that drives our responses to everything from hot pans to a mother’s caress.

Fat is proposed as a candidate sixth basic taste

Oleogustus is Latin for "a taste for fat," and researchers proposed in 2015 that it should be accepted as the sixth basic taste. This article teases apart exactly what it would take to officially be considered the sixth taste and why researchers think the fat taste may be a strong candidate.

How science came to understand umami

Before Dr. Kikunae Ikeda sat down in 1907 and pondered the taste of dashi, scientists typically agreed upon four types of taste: sweet, salty, bitter, and sour. He boiled 90 pounds of kelp into a resin that he then stripped of different compounds until he was left with a single ounce of brown crystals. Testing later revealed these crystals were glutamate, an amino acid and one of the protein's building blocks.

Miracle berries make things that normally taste acidic or sour, such as lemons, taste sweet, like sugar-coated candy, by binding a special protein called miraculin to taste buds.

Sensory memory is information collected from your senses

Lasting seconds before moving into short-term memory or being forgotten, sensory memory aids in environmental awareness and navigation. Key brain regions involved include auditory, somatosensory, gustatory, visual, and olfactory cortices.

A web of sensory neurons in the skin help filter out background sensations

The somatosensory system helps us organize and navigate our surroundings, enabling us to understand our bodies in relation to our environment and also filter out minor sensations that are basically background noise so they aren't overwhelming to our bodies. Meanwhile, viscerosensation—or internal sensation—refers to the internal sensory neuron system that conveys information from internal organs to the brain.