10 Amazing Facts About the Infant Brain

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While there’s little argument that babies are generally cute, it’s far more difficult to determine how intelligent they are, since we can’t measure their know-how by standards of adult brain development. Yet infants’ brains develop so rapidly they are pure, consolidated potential in their first three years. Consider that a 4-week-old fetus forms new neurons at a rate of 250,000 every minute, and by the time a child is three, their brain will reach 80 percent of adult volume and process close to 1000 trillion connections between neurons. Here are 10 mind-blowing facts about the amazing infant brain.

1. ALL BABIES ARE BORN "EARLY."

Thanks to the size of the average human birth canal, and the heavy metabolic burden a baby places on its mother in gestation, a baby’s head can only be so big and still emerge from its mother, which means babies are born with underdeveloped brains that are hypersensitive to stimulus. One popular theory explaining this is that their first three months of life outside the womb equal a “fourth trimester” which may be why newborns like to be wrapped tightly and respond well to loud white noise, details which mimic the conditions of life in utero. Further theory suggests that humans are designed to be social and cultural animals, and that being born earlier may allow an infant’s brain to soak up the many impressions and senses of being raised within a group of people. 

2. BABIES ARE BORN WITH ALL THE NEURONS THEY WILL EVER HAVE. 

Assuming normal development, a healthy baby will emerge from the womb with 100 billion neurons, nearly twice as many neurons as adults, in a brain that’s half the size. This massive number of neurons is necessary for the tremendous amount of learning a baby has to do in its first year of life. While brain volume will double by the age of 3, not all of those neurons will stick around; synaptic pruning takes place as a baby ages, in which the brain gets rid of weaker synaptic connections in favor of stronger ones.  

3. BIRTH TO AGE 3 SEES THE FASTEST RATE OF BRAIN DEVELOPMENT IN THE ENTIRE HUMAN LIFE SPAN.

Though you may think your darling is growing like a weed as chubby toddlerhood gives way to lanky kid, in the first three years of your child’s life, their brain is growing faster than any other body part. At birth, a baby's brain is about one-third the size of an adult's brain. In 90 days, it more than doubles its volume, to 55 percent of its final size. The cerebellum in particular, a brain structure at the back of the brain involved in controlling movement, grows the fastest of all brain structures; in just three months it will be 110 percent bigger than it was at birth.

4. MOST OF THE ENERGY A BABY EXPENDS IS CONCENTRATED IN THE BRAIN.

As a result of all that rapid brain development, 60 percent of a baby’s metabolic energy (primarily the consumption of glucose) is spent on growing those soon-to-be massive brains. In contrast, the brain of an adult uses only about 25 percent of the body’s metabolic energy. 

5. BABIES' BRAINS PREPARE FOR SPEECH LONG BEFORE THEY UTTER A WORD. 

A study of 7-month-old babies at the University of Washington showed activation of motor parts of babies’ brains associated with the physical aspects of speech—Broca’s area and the cerebellum—before they actually began to speak. This suggests that the brain sets up a transitional groundwork in a process known as “analysis by synthesis” in which the brain predicts the motor movements that will be required to make the sounds of speech and prepares to do so.

6. BILINGUAL BABIES' BRAINS HAVE STRONGER EXECUTIVE FUNCTION.

Not only are babies capable at birth of learning any language, those babies who are spoken to regularly in two or more languages have better executive function later in life, specifically the ability to control attention to conflicting perceptual or representational features of a problem. In other words, bilingual children have better attention or focus, which bodes well for school and work performance. 

7. PHYSICAL TOUCH STRENGTHENS BABIES' SYNAPSES.

Babies who receive regular touch have stronger neuronal connections, and greater overall well-being. It’s well known now that babies who are deprived of touch suffer a number of negative health effects, from low weight to emotional disorders such as anxiety and depression. A study of 92 7- to 9 year-olds, who had previously been studied in preschool, showed that those who had received more nurture by their mothers (or caregivers) had a thicker hippocampus than those who were not as well nurtured. A stronger hippocampus is associated with improved memory, better focus, ability to retain learning, and more.

8. BABY BRAINS ARE HARDWIRED TO PREFER THEIR MOTHER'S SCENT.

Much of the infant-mother bond in the early days is determined by smell and touch, more specifically the bonding hormone oxytocin, which can induce a feeling of euphoria and love in humans. Studies have shown that babies are imprinted with, and attracted to, the scent of their own amniotic fluid, which helps them to find their mother’s nipple. Over several days, healthy babies grow to prefer the scent of their mother’s breast. One study even showed that formula-fed babies still prefer the odor of their mother’s breast to that of their formula up to two weeks after birth.

9. A BABY'S UNWILLINGNESS TO LEAVE A PARENT SIGNALS THE DEVELOPMENT OF LONG-TERM MEMORY.

Mothers who find they must pry a suddenly crying baby off of them when they prepare to leave might be relieved to know it may be the earliest signs of long-term memory development. Jerome Kagan, a Harvard University professor of psychology, suggests that around 9 months, an infant’s unwillingness to leave their parent is a sign that the child has a clear memory of his or her mother “being there” and can now form an emotional association to the event. 

10. HYPOTHERMIA CAN PROTECT NEWBORN BRAINS. 

A new study at Children’s Hospital Los Angeles of newborns treated for hypoxic-ischemic encephalopathy (HIE)—a condition that occurs when the brain is deprived of an adequate oxygen supply—found that inducing hypothermia through a targeted cooling of the brain had a neuroprotective effect.

Without treatment, these babies often develop cerebral palsy or other severe complications that affect as many as 1 million babies worldwide. The study found that hypothermia works by reducing energy metabolism, but also reduced the synthesis of glutamate and other excitatory neurotransmitters.   

12 Facts About the Sense of Taste

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A lot more than your tongue is involved in the process of tasting food. Taste is not only one of the most pleasurable of the five senses, but a surprisingly complex sense that science is beginning to understand—and manipulate. Here are 12 fascinating facts about your ability to taste.

1. Everyone has a different number of taste buds.

We all have several thousand taste buds in our mouths, but the number varies from person to person. The average range is between 2000 and 10,000. And taste buds are not limited to your tongue; They can be found in the roof and walls of your mouth, throat, and esophagus. As you age, your taste buds become less sensitive, which experts believe may be why foods that you don’t like as a child become palatable to you as an adult.

2. You taste with your brain.

The moment you bite into a slice of pie, your mouth seems full of flavor. But most of that taste sensation is happening in your brain. More accurately, cranial nerves and taste bud receptors in your mouth send molecules of your food to olfactory nerve endings in the roof of your nose. The molecules bind to these nerve endings, which then signal the olfactory bulb to send smell messages directly to two important cranial nerves, the facial nerve and the glossopharyngeal nerve, which communicate with a part of the brain known as the gustatory cortex.

As taste and nerve messages move further through the brain, they join up with smell messages to give the sensation of flavor, which feels as if it comes from the mouth.

3. You can’t taste well if you can’t smell.

When you smell something through your nostrils, the brain registers these sensations as coming from the nose, while smells perceived through the back of the throat activate parts of the brain associated with signals from the mouth. Since much of taste is odor traveling to olfactory receptors in your brain, it makes sense that you won’t taste much at all if you can’t smell. If you are unable to smell for reasons that include head colds, smoking cigarettes, side effects of medications, or a broken nose, olfactory receptors may either be too damaged, blocked, or inflamed to send their signals on up to your brain.

4. Eating sweet foods helps form a memory of a meal.

Eating sweet foods causes your brain to remember the meal, according to a 2015 study in the journal Hippocampus, and researchers believe it can actually help you control eating behavior. Neurons in the dorsal hippocampus, the part of the brain central to episodic memory, are activated when you eat sweets. Episodic memory is that kind that helps you recall what you experienced at a particular time and place. "We think that episodic memory can be used to control eating behavior," said study co-author Marise Parent, of the Neuroscience Institute at Georgia State. "We make decisions like 'I probably won't eat now. I had a big breakfast.' We make decisions based on our memory of what and when we ate."

5. Scientists can turn tastes on and off by manipulating brain cells.

Dedicated taste receptors in the brain have been found for each of the five basic tastes: sweet, sour, salty, bitter, and umami (savory). In 2015, scientists outlined in the journal Nature how they were able to turn specific tastes on or off in mice, without introducing food, by stimulating and silencing neurons in the brains. For instance, when they stimulated neurons associated with “bitter,” mice made puckering expressions, and could still taste sweet, and vice versa.

6. You can tweak your taste buds.

Most of us have had the experience of drinking perfectly good orange juice after brushing our teeth, only to have it taste more like unsweetened lemon juice. Taste buds, it turns out, are sensitive enough that certain compounds in foods and medicines can alter our ability to perceive one of the five common tastes. The foaming agent sodium lauryl/laureth sulfate in most toothpaste seems to temporarily suppress sweetness receptors. This isn't so unusual. A compound called cynarin in artichokes temporarily blocks your sweet receptors. Then, when you drink water, the cynarin is washed away, making your sweet receptors “wake up” so the water tastes sweet. A compound called miraculin, found in the herb Gymnema sylvestre, toys with your sweet receptors in a similar way.

7. The smell of ham can make your food “taste” saltier.

There’s an entire industry that concocts the tastes of the food you buy at the grocery store. Working with phenomena known as phantom aromas or aroma-taste interactions, scientists found that people associate “ham” with salt. So simply adding a subtle ham-like scent or flavor to a food can make your brain perceive it as saltier than it actually is. The same concept applies to the scent of vanilla, which people perceive as sweet.

8. Your taste buds prefer savory when you fly.

A study by Cornell University food scientists found that loud, noisy environments, such as when you’re traveling on an airplane, compromise your sense of taste. The study found that people traveling on airplanes had suppressed sweet receptors and enhanced umami receptors. The German airline Lufthansa confirmed that on flights, passengers ordered nearly as much tomato juice as beer. The study opens the door to new questions about how taste is influenced by more than our own internal circuitry, including our interactions with our environments.

9. Picky eaters may be “supertasters.”

If you’re a picky eater, you may have a new excuse for your extreme dislike of eggplant or sensitivity to the slightest hint of onion. You might be a supertaster—one of 25 percent of people who have extra papillae in your tongue. That means you have a greater number of taste buds, and thus more specific taste receptors.

10. Some of your taste preferences are genetic.

While genetics may not fully explain your love of the KFC Double Down or lobster ice cream, there may be code written into your DNA that accounts for your preference for sweet foods or your aversion to certain flavors. The first discovery of a genetic underpinning to taste came in 1931, when chemist Arthur Fox was working with powdered PTC (phenylthiocarbamide), and some of the compound blew into the air. One colleague found it to have a bitter taste, while Fox did not perceive that. They conducted an experiment among friends and family and found wide variation in how (and whether) people perceived the flavor of the PTC to be bitter or tasteless. Geneticists later discovered that the perception of PTC flavor (similar to naturally occurring compounds) is based in a single gene, TAS2R38, that codes for a taste receptor on the tongue. In a 2005 study, researchers at the Monell Chemical Senses Center found that the version of this gene also predicted a child's preference for sweet foods.

11. Your genes influence whether you think cilantro tastes like soap.

There may be no flavor more hotly debated or deeply loathed than the herb cilantro (also known as coriander). Entire websites, like IHateCilantro.com, complain about its “soapy” or “perfumy” flavor, while those who like it simply think it gives a nice kick to their salsa. Researchers at the consumer genetics company 23andMe identified two common genetic variants linked to people's “soap” perceptions. A follow-up study in a separate subset of customers confirmed the associations. The most compelling variant can be found within a cluster of olfactory receptor genes, which influence our sense of smell. One of those genes, OR6A2, encodes a receptor that is highly sensitive to aldehyde chemicals, which cilantro contains.

12. Sugar cravings have a biological basis.

Your urge for more hot fudge may have little to do with a lack of self-control. Scientists think that our yearning for sweets is a biological preference that may have been designed to ensure our survival. The liking for sweet tastes in our ancient evolution may have ensured the acceptance of sweet-tasting foods, such as breast milk and vitamin-rich fruits. Moreover, recent research suggests that we crave sweets for their pain-reducing properties.

12 Facts About the Pancreas

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iStock.com/ericsphotography

You could live without your pancreas, but it wouldn’t be easy. For one, you would need to give yourself insulin shots on a daily basis because you would develop diabetes. A helping of enzyme pills would also be needed to help you digest food. It's clear that the 6-inch-long pancreas, located behind your stomach, has crucial functions—and that's why diseases like pancreatic cancer and pancreatitis are often so devastating. Here are a few other important facts to know about the pancreas.

1. Pancreas means “all flesh” in Greek.

Around 300 BCE, a surgeon in ancient Greece named Herophilus became the first person to formally describe the pancreas as a gland. However, the organ didn’t get its name until about 400 years later, when another Greek surgeon and anatomist named Ruphos dubbed it the pankreas, meaning “all flesh”—possibly because of its lack of bone or cartilage. (The plural of pancreas, by the way, is pancreata or pancreases.) Later, in the 16th century, people started referring to a dish of cooked calf or lamb pancreas as “sweetbreads.” That name possibly stems from bræd, the Old English word for “flesh.”

2. The pancreas has a head and a tail.

The pancreas has four main parts: the head, neck, body, and tail. The widest part is the head, which is attached to the first part of the small intestine, known as the duodenum. In cases where a pancreatic tumor is present, the head is usually the part that’s affected. However, according to one study from 2008, people with tumors in the body or tail of the pancreas had lower survival rates than those with cancer in the head of the pancreas.

3. The man who discovered the pancreatic duct may have been murdered for his work.

The pancreatic duct is a tiny tube that runs the length of the pancreas and carries digestive juices to the duodenum. Although the ancient Greeks knew about the pancreas, its function and anatomy weren’t fully understood for centuries. That started to change in 1642, when German anatomist Johann Georg Wirsung discovered the pancreatic duct after performing a dissection on a man who had been hanged for murder. He named it the “duct of Wirsung” after himself, which may have upset some people. Wirsung was murdered the following year, allegedly over a disagreement as to who had actually discovered the duct.

4. It functions as both an endocrine and exocrine gland.

Although food never enters the pancreas, the organ does play a key role in digestion. It produces pancreatic fluid, which gets piped through the pancreatic duct to the duodenum. Once it’s in the digestive tract, the enzymes in the fluid help break down fat, protein, and carbohydrates. By sending a substance through ducts to other parts of the body, it functions as an exocrine gland. At the same time, it also functions as an endocrine gland by secreting two hormones directly into the bloodstream to help control blood sugars. Insulin is released when you have too much sugar, and glucagon is released when you don’t have enough sugar.

5. The pancreas can “taste” sugar.

The pancreas has taste receptor cells that let it sense the presence of sugar. It can “taste” artificial sweeteners, too. However, unlike the taste buds on our tongue, it doesn’t relay these sensations back to the brain. Instead, this sensory information helps the pancreas balance out the hormones and maintain healthy glucose levels in the body.

6. Diabetes is the result of damage to pancreatic cells.

For reasons that remain a scientific mystery, people with type 1 diabetes have immune systems that attack the insulin-producing cells in their pancreas. This prevents the cells from making insulin, and without insulin, other cells can't access the glucose in the bloodstream for energy. Sugar then builds up unhealthily in the bloodstream. People with type 2 diabetes, on the other hand, can still produce some insulin, but it’s not enough. Their cells become resistant to insulin (often as a result of obesity), which causes glucose to accumulate in the bloodstream.

7. The pancreas can digest itself.

Pancreatitis refers to the inflammation of the pancreas, but more alarmingly, what’s actually happening is that the digestive enzymes in the gland are going rogue and “digesting the pancreas itself,” according to Medline Plus. Heavy alcohol consumption is the most common cause of the disease, but other causes may include gallstones, cystic fibrosis, or high levels of fats or calcium in the blood. Most people with acute pancreatitis end up in the hospital, and it often goes away in a couple of days. Chronic pancreatitis can result in more serious complications.

8. Scorpion stings can cause pancreatitis.

The venom of a Brazilian scorpion, Tityus serrulatus, can cause pancreatitis, according to researchers at North Carolina State University. One particular enzyme in the venom attacks certain proteins in the gland, which impairs the pancreatic cells' functions and leads to inflammation. In a separate study of a related species (T. stigmurus), researchers found that “acute pancreatitis due to scorpion is usually transient [and] self-limited ... but it could progress to hemorrhagic pancreatitis and lead to death.”

9. Ruth Bader Ginsburg beat the odds and survived pancreatic cancer.

Ten years after she recovered from colon cancer, Ruth Bader Ginsburg received bad news following a routine check-up in 2009: She had pancreatic cancer. Fortunately, surgeons were able to remove the tumor, and at 85 years old (and counting), Ginsburg is now the oldest Justice on the U.S. Supreme Court. However, most people with pancreatic cancer aren’t so lucky. Although it’s less prevalent than skin, breast, and prostate cancers, it’s one of the deadliest. Just 8 percent of pancreatic cancer patients in the U.S. live longer than five years, according to the American Cancer Society.

James Cleary, an oncologist at the Dana-Farber Cancer Institute in Boston, says it’s very hard to catch in the early stages. “The reason pancreatic cancer can be so difficult to catch is number one, it’s a fast-moving cancer and can grow very rapidly,” he tells Mental Floss. “And number two, it can grow in a spot where you don’t get any symptoms until it’s too late.” In some cases, the cancer may start in the pancreas and spread to the liver or lining of the abdomen without any symptoms showing up.

10. Pancreatic surgery is extremely difficult to pull off.

Sometimes, patients with pancreatic cancer will undergo a complicated surgery called a Whipple procedure, which involves the removal of the head of the pancreas, part of the small intestine, the gallbladder and bile duct, and sometimes part of the stomach, too. However, very few people with pancreatic cancer are candidates for surgery—even if the cancer hasn’t yet spread to neighboring organs. That’s because cancer cells sometimes surround important blood vessels, making it “a tricky area” to operate on, according to Cleary. “The pancreas plays a really important role in digestion, and because of that, it’s very close to several important blood vessels and it’s very close to the stomach and small intestine,” he says.

11. There are genetic components to pancreatic cancer.

More than 90 percent of pancreatic cancers involve a mutation of the KRAS gene, which is also responsible for about half of all human cancers, according to Cleary. However, a drug hasn’t been invented yet to turn this particular gene off. “Finding a way to make a drug successfully target KRAS is one of holy grails of oncology," Cleary says. "It is of such great importance to oncology that a Nobel Prize could be awarded to whoever figures out how to make effective KRAS targeted therapy."

Mutations of DNA repair genes occur in up to 20 percent of pancreatic cancer cases. Some of these mutated genes, like BRCA1 and BRCA2, can run in families. This is why some families have several members who end up suffering from pancreatic cancer. Jimmy Carter, for example, lost his father, brother, and two sisters to pancreatic cancer. His mother had breast cancer that migrated to her pancreas. PARP inhibitors (drugs that block a particular enzyme) have been used to target DNA repair genes in breast and ovarian cancers, and there is now hope that they may also be effective in treating pancreatic cancer.

12. An aggressive form of chemotherapy is helping pancreatic cancer patients live longer.

A chemotherapy regimen called FOLFIRINOX has made significant improvements in the care of pancreatic cancer patients ever since it was introduced in 2010 as a treatment for patients with metastatic disease. Before 2010, “It was very, very rare to see anyone with metastatic cancer living longer than one year,” Cleary says. With FOLFIRNOX, it's not uncommon to see patients with metastatic pancreatic cancer living two years. A huge step forward came in June 2018 when researchers from France found that giving FOLFIRINOX after surgery could increase survival by a median of 20 months longer compared to the standard chemotherapy. Now, researchers are conducting trials to see if FOLFIRINOX can effectively be administered before a patient undergoes surgery. Considering that most patients aren’t eligible for surgery at diagnosis, pre-operative FOLFIRINOX could shrink the pancreatic tumor and increase the number of patients that are able to safely receive surgery.

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