National Geographic Tales of the Weird
Page 7
TRUTH:
BRAIN CELLS LIVE LONGER THAN ANY OF THE OTHER CELLS IN YOUR BODY.
Paul Aisen, a neuroscientist and director of the Alzheimer’s Disease Cooperative Study at the University of California, San Diego, said the study is “another incremental advance” from a strong group of scientists, but it’s “uncertain whether this will have implications for treatment for humans.” That’s because “measuring … firing at the level of a single cell, a neuron, is difficult to extend to human behavior, which is highly complex. It’s not so much that a monkey is not a human—it’s that this kind of single-cell recording is a very isolated aspect of brain function.”
Do We Need Brain Changers?
A bigger question, Aisen added, is whether age-related memory decline really needs drug treatment. “In the absence of a disease such as Alzheimer’s, people [compensate] quite well despite the decline in memory,” he said. For example, some elderly people combat forgetfulness by simply writing things down.
But study leader Arnsten argues that the fight against cognitive decline is still crucial for many otherwise healthy people. “These abilities are critical for managing one’s finances, for being able to manage one’s medical treatment, and [to] live independently.”
NIGHT OWLS AND EARLY BIRDS
Your Hair Reveals if You’re a Morning Person
Not sure if you’re a morning person or a night owl? Don’t worry. Your hair knows.
Early bird or late riser? The mysteries of your sleep cycle may be unlocked by the hairs on your head, a new study says. That’s because the genes that regulate our body clocks can be found in hair-follicle cells, researchers have discovered.
A tiny portion of the brain called the suprachiasmatic nucleus controls the human body clock, and RNA strands—protein-building chains of molecules—process these signals throughout the body in 24-hour cycles.
(Photo Credit 2.7)
Predicting Morning People
RNA strands containing the clock genes are found throughout the body—including in white blood cells and inside the mouth—but human hair is easiest for scientists to test.
So Makoto Akashi, of the Research Institute for Time Studies at Yamaguchi University in Japan, and colleagues pulled head and beard hairs from four test subjects at three-hour intervals for a full day.
The subjects had already reported their preferred schedules for waking up and eating, among other lifestyle choices. The test day occurred after the subjects had rigorously adhered to their preferred schedules for nine days—in other words, the morning people woke up early every day and the late sleepers woke up late every day.
When the researchers tested the genes in the subjects’ follicles, they found that body-clock gene activity peaked right after a subject had woken up, regardless of whether it was 6 a.m. or 10 a.m. This suggests that the brain “turns on” the genes at different times of the morning in different people. Other clock genes followed similar patterns, making it possible to predict “morning people” with just a pluck, the study said.
Time on Your Skin
In addition to hair, our biological clocks can also be detected in our skin cells. Research done at the Institute for Pharmacology and Toxicology at the University of Zurich, Switzerland, found that genes have a major influence on our circadian clock. These cells can provide a precise look at a person’s daily body clock by mirroring the molecular operations of the brain’s central clock, and such research may lead to new treatments for those who suffer from sleep disorders.
Body-Clock Disorders
While most people may already know if they prefer to sleep in or wake up early, the new research might also provide insights into human health, researchers say. Disorders of the body clock have been implicated in high blood pressure, diabetes, and even cancer.
The researchers also studied the hairs of rotating shift workers, who are at greater risk for body-clock disorders, for three weeks. During that amount of time, the workers alternated from an early work shift (6 a.m. to 3 p.m.) to a late shift (3 p.m. to midnight).
But the three-week period wasn’t enough time for the workers’ internal clocks to readjust, according to measurements of follicle genes. Even though the workers’ lifestyle was shifted by seven hours, the clock-gene activity in their follicles shifted by only two hours—suggesting shift workers live in a state of jet lag, the study said.
Scanning electron micrograph of a hair follicle (Photo Credit 2.8)
TRUTH:
HAIR GROWS ALMOST EVERYWHERE ON YOUR SKIN EXCEPT YOUR LIPS, THE PALMS OF YOUR HANDS, AND THE SOLES OF YOUR FEET.
Early Warning Systems?
The follicle test could be used to develop “working conditions that do not disturb clock function” by building in enough time to adjust, the authors wrote. A noninvasive check for a clock disorder could serve as an early warning system. Akashi said: “I hope that our method will be used for regular health checks in schools and companies to keep healthy clocks.”
THE MYSTERY OF NO FINGERPRINTS
Mutated DNA
Causes No-Fingerprint Disease
A genetic mutation causes people to be born without fingerprints, experts say.
Almost every person is born with fingerprints, and everyone’s are unique. But people with a rare disease known as adermatoglyphia do not have fingerprints from birth. Affecting only four known extended families worldwide, the rare condition is also called immigration-delay disease, since a lack of fingerprints makes it difficult for people to cross international borders.
Coming Up Empty-Handed
In an effort to find the cause of the disease, dermatologist Eli Sprecher sequenced the DNA of 16 members of one family with adermatoglyphia in Switzerland. Seven had normal fingerprints, and the other nine did not. After investigating a number of genes to find evidence of mutation, the researchers came up empty-handed—until a grad student finally found the culprit, a smaller version of a gene called SMARCAD1.
The larger SMARCAD1 is expressed throughout the body, but the smaller form acts only on the skin. Sure enough, the nine family members with no fingerprints had mutations in that gene.
Being born without fingerprints doesn’t occur simply because one gene has been turned on or off, Sprecher said. Rather, the mutation causes copies of the SMARCAD1 gene to be unstable.
That mutation is also the first link in a long chain of events that ultimately affects fingerprint development in the womb. The rest of the links in the chain are still a mystery, said Sprecher, of the Tel Aviv Sourasky Medical Center.
No Harm, No Foul
Other inherited diseases that result in a lack of fingerprints—such as Naegeli syndrome and dermatopathia pigmentosa reticularis—are caused by problems with the protein keratin-14.
These conditions “manifest not only with lack of fingerprints, but also with a number of other critical features—a thickening of the skin, problems with nail formation,” Sprecher said. By contrast, immigration-delay disease doesn’t come with any side effects besides a minor reduction in the ability to sweat. In general, people with the disease “are otherwise completely healthy, like you and me.”
TRUTH:
KIDS’ FINGERPRINTS DISAPPEAR FROM SURFACES FASTER THAN ADULTS’ DO.
Through further study of the Swiss family, Sprecher said, it might be possible to solve the mystery of fingerprints overall. “You go from a rare disease to a biological insight of general importance,” he said. “We would never have been able to get to this gene if not for the study of this family.”
SINGING SMARTLY
Making Music
Bolsters the Brain’s Abilities
Music may be the food of love, but science is showing it nourishes a relationship with your mind as well.
Music may soothe the savage beast, but it can also bring out the best in your brain. “In the past ten years there’s been an explosion of research on music and the brain,” said Aniruddh Patel, the Esther J. Burnham Senior Fellow at the Neurosciences Insti
tute in San Diego.
Most recently, brain-imaging studies have shown that music activates many diverse parts of the brain, including an overlap where the brain processes music and language. Language is a natural aspect to consider in looking at how music affects the brain, Patel said. Like music, language is “universal, there’s a strong learning component, and it carries complex meanings.”
Above the Din
Do you have trouble hearing people talk at cocktail parties? Try practicing the piano before you leave the house. Musicians—from karaoke singers to professional cellists—are better able to hear targeted sounds in a noisy environment.
Brains of people exposed to even casual musical training have an enhanced ability to generate the brain wave patterns associated with specific sounds, be they musical or spoken, said study leader Nina Kraus, director of the Auditory Neuroscience Laboratory at Northwestern University in Illinois.
Music as Medicine
For decades, music therapy has been practiced to treat a variety of neurological ailments, from Parkinson’s and Alzheimer’s to anxiety and depression. In addition to improving movement and speech, music can also elicit mood-altering brain chemicals and past memories and emotions.
Playing a musical instrument enhances listening abilities. (Photo Credit 2.9)
Kraus’s previous research had shown that when a person listens to a sound, the brain wave recorded in response is physically the same as the sound wave itself. In fact “playing” the brain wave produces a nearly identical sound.
But for people without a trained ear for music, the ability to make these patterns decreases as background noise increases, experiments show. Musicians, by contrast, have subconsciously trained their brains to better recognize selective sound patterns, even as background noise goes up.
The overall effect is like a person learning to drive a manual transmission, Kraus said. “When you first learn to drive a car, you have to think about the stick shift, the clutch, all the different parts, but once you know, your body knows how to drive almost automatically.”
At the same time, people with certain developmental disorders, such as dyslexia, have a harder time hearing sounds amid the din—a serious problem, for example, for students straining to hear the teacher in a noisy classroom. Musical experience could therefore be a key therapy for children with dyslexia and similar language-related disorders, Kraus said.
“Without music, life would be a mistake.”
Friedrich Nietzsche
The Sound of Music
In a similar vein, Harvard Medical School neuroscientist Gottfried Schlaug has found that stroke patients who have lost the ability to speak can be trained to say hundreds of phrases by singing them first. Schlaug’s research demonstrated the results of intensive musical therapy on patients with lesions on the left side of their brain—the area most associated with language.
Before the therapy, these stroke patients responded to questions with largely incoherent sounds and phrases. But after just a few minutes with therapists, who asked them to sing phrases and tap their hands to the rhythm, the patients could sing “Happy Birthday,” recite their addresses, and communicate if they were thirsty.
“The underdeveloped systems on the right side of the brain that respond to music became enhanced and changed structures,” Schlaug said.
Success varied depending on how recently a person had had a stroke and the severity of the damage, he noted. But several patients were eventually able to teach themselves new words and phrases by turning them into tunes, and a few were even able to move beyond simple phrases and give short speeches. Overall, Schlaug said, the experiments show that “music might be an alternative medium for engaging parts of the brain that are otherwise not engaged.”
Northwestern’s Kraus agreed. She added that musical training, whatever the age, should be universally encouraged, since it can play a key role in education, clinical therapies, and even in protective measures for keeping the brain sharp as people age. “Plus,” she said, “it’s just inherently wonderful.”
“Participants report that their control of physical movement improves after playing the drums, their motion becomes more fluid, they don’t shake quite as much, and their tremors seem to calm down.”
Rick Bausman
founder and director, Drum Workshop, on working with Parkinson’s patients
ANCIENT “PICKLED” BRAIN
The 2,500-Year-Old Brain
How did an unusually well-preserved 2,500-year-old brain stay in such good shape? A team of scientists were determined to solve the mystery.
Scientists may have partially cracked how Britain’s oldest known human brain was “pickled” in mud for some 2,500 years. First dug up in 2008 by archaeologists in York, England, the well-preserved chunk of ancient gray matter prompted experts to investigate how the brain had stayed in such good shape.
TRUTH:
IN ANCIENT EGYPT, MUMMIES’ BRAINS WERE REMOVED THROUGH THE NOSE.
Brain Preservation
Results of a new study found no chemical signs of deliberate preservation, either by embalming or smoking. Instead, the team suggests that the brain was quickly buried in a pit full of thick, wet clay—among several other factors that may have helped prevent the organ from decomposing.
Protein analysis also confirms the ancient brain—dated to between 673 and 482 B.C.—belonged to a human, said study co-author Matthew Collins, an archaeologist at the University of York. “The majority of the mass of the brain is still there, but it’s quite reduced in volume—it’s lost a lot of water.”
Hanged, Then Decapitated
Analyses of the brain and remains of the surrounding skull suggest the Iron Age brain belonged to a male between 26 and 45 who was hanged and then ritually decapitated. The evidence? Gruesome neck-vertebra fractures and cut marks show that hanging occurred before his head was sliced off after death with a sharp instrument, scientists say. The rest of the man’s body hasn’t been located.
The presumably fatal neck injury “is sometimes referred to as a hangman’s fracture, and it is consistent with a long-drop hanging,” said study co-author Jo Buckberry an archaeologist at the University of Bradford. “On the same vertebra there are a series of nine small incisions made by a bladed instrument, which are consistent with a careful decapitation,” Buckberry said. “My feeling is the individual would have died from the fracture and the head was removed and deposited in the pit.”
“In the air, even in the chill of a hospital mortuary, brain tissue very quickly decays to liquid before muscle and other soft tissues show much evidence of decay.”
Sonia O’Connor
postdoctoral research associate, University of Bradford
A Quick Burial
The fact that the skull was found with intact jaw and neck bones shows the head was buried fresh. “If you moved the skull at a later date, the soft tissue would have decayed”—resulting in the jaw and vertebrae coming detached, said Buckberry, whose study appeared in the Journal of Archaeological Science.
In addition to the rapid burial, the cool, low-oxygen conditions of the soil may have aided the brain’s preservation, the team found. Cooler temperatures would have slowed the rate at which enzymes degraded the brain tissue, while a lack of oxygen in the soil would have reduced microbial action, the University of York’s Collins noted.
Ain’t Got No Body
The fact that the head was missing its body may have also kept the brain intact. “Humans that have been buried tend to be eaten from the inside out,” Collins said. “Once you’ve died, the gut bacteria are still pretty hungry.”
A computer-generated scan of a 2,500-year-old human skull shows brain matter in dark gray. The lighter gray colors in the skull represent soil. (Photo Credit 2.10)
These bacteria flood the corpse via blood from the alimentary tract—the digestive pathway through the body—and consume surrounding tissue. “In this case, the blood will have drained from the severed head, and you’ve no
longer got a connection with the alimentary tract.”
Still a Mystery
Still, these theories don’t fully explain why the brain “didn’t turn into mush,” Collins said. “It’s curious, because normally it is one of those organs that degrade quickly,” he said. “There must be something going on internally that we don’t understand.”
To further investigate the phenomenon, researchers have buried pigs’ heads in and around the pre-Roman site, to simulate what may have happened.
Dinosaur, Whole Please
In 1999, then-16-year-old Tyler Lyson discovered the world’s most intact dinosaur mummy—the 67-million-year-old hadrosaur, a duck-billed herbivore. In addition to fossilized bones and skin tissue, muscle and organs were also unearthed. It is speculated that the dinosaur was rapidly buried in mineral-rich wet sand, which prevented bacteria from decomposing all of its tissue.
REAL-LIFE CAVEMAN DIET
Eating Crocodile
Helped Boost Early Human Brains?
The secret to bigger brains, for early humans anyway, could have been a diet rich in fat, courtesy of crocodiles, a new study suggests.
Eating the fatty flesh of crocodiles may have helped early humans evolve bigger brains, a new study suggests. The work is based on bones and artifacts from a prehistoric “kitchen” that make up the earliest evidence that humans ate aquatic animals.