Friday, July 30, 2010

How the neck helped evolution of human brain

The neck gave humans so much freedom of movement that it played a major role in the evolution of the human brain, according to new research.
The study, conducted by neuroscientists at New York University and Cornell University, appears online in the journal Nature Communications.
Scientists had assumed the pectoral fins in fish and the forelimbs (arms and hands) in humans are innervated - or receive nerves - from the exact same neurons. After all, the fins on fish and the arms on humans seem to be in the same place on the body. Not so.
During our early ancestors' transition from fish to land-dwellers that gave rise to upright mammals, the source for neurons that directly control the forelimbs moved from the brain into the spinal cord, as the torso moved away from the head and was given a neck. In other words human arms, like the wings of bats and birds, became separate from the head and placed on the torso below the neck.
"A neck allowed for improved movement and dexterity in terrestrial and aerial environments. This innovation in biomechanics evolved hand-in-hand with changes in how the nervous system controls our limbs," said Andrew Bass, Cornell professor of neurobiology and behavior, and an author on the paper.
Bass explained that this unexpected level of evolutionary plasticity likely accounts for the incredible range of forelimb abilities - from their use in flight by birds to swimming by whales and dolphins, and playing piano for humans.

Exercise benefits your body and brain as you age

A variety of scientific studies demonstrate the powerful benefits of exercise on our bodies and brains, particularly as we age. The studies were reported in the Jan. 25 edition of the Archives of Internal Medicine. Here is a brief summary of several of the studies:
• Experts have believed that aerobic exercise enhances cognitive function by promoting blood flow to the brain. One anaerobic study indicated that resistance training (weight training) improved memory, learning, decision making and conflict resolution. The resistance training also improved walking speed, and a faster walking pace has been linked to lower mortality. Weight-training also increases a growth factor associated with maintaining skeletal mass, and this same factor also promotes nerve growth (which may be another way to boost mental functions).
• Another study indicated higher levels of physical activity led to lower incidences of dementia. However, any level of physical activity can be helpful for brain strengthening, according to the study.
• Yet another study showed that women who jogged three hours or more per week (or walked briskly for five hours) were 76 percent more likely to age successfully than women who jogged only 20 minutes a week. Successful aging in this study meant freedom from chronic illnesses such as cancer and heart disease.
Another study found that regular weekly exercise sessions led to a significantly lower risk of experiencing a fracture-causing fall than those who did not exercise regularly.
While no one may yet be ready to say regular exercise (aerobic and anaerobic) is a sure-fire preventative for common physical illnesses and mental frailties as you age, there is more and more evidence that exercise is good for you physically and mentally. So look at your own exercise regime. If you’ve limited yourself to walking or jogging or other aerobic workouts, perhaps it’s time to spend some time in the gym working out with weights. You can buff up your bod and your brain at the same time.

Help Your Brain Get Better with Time

(CBS)  New research shows that our brains actually do get wiser as we get older. Studies now show that our brain hits its peak in midlife-between the ages of 40 and 60-much later than previously thought.

"Early Show" Medical Correspondent, Dr. Jennifer Ashton has tips on how to stay sharp well into old age.

The Seattle Longitudinal Study, one of the largest and longest, says that the brain drain doesn't really start until our early seventies. This research group has followed six thousand people, testing them every seven years since 1956.

When it came to cognitive testing, many people did better in their forties and fifties than they had done when they were in their twenties. Middle agers ranked higher in scores on deductive reasoning, spatial orientation skills (what an object would look like rotated 180 degrees), verbal memory, and problem solving.

However, middle age brains did have a little trouble with mental skills involving speed, such as rapid number computation, and perceptual speed-how fast you can push a button when prompted. With age, the brain is less susceptible to dopamine-a hormone that can cause us to be impulsive-making middle aged brains better at decision making.

Another study sponsored by the NIH (National Institute of Health) found that while most people experience some cognitive decline as they age, nearly a third of the population doesn't.

Though it is not conclusively known, Ashton explains that a theory behind why this occurs is the increase of fatty substance called myelin "which you can think of as the insulation around those brain synapses."

The older brain may work well because of life experiences, but it also has a lot to do with physiological factors such as genetics. While peak brain power may come at middle age, it can be short lived.

To keep your brain humming for longer, Ashton suggests working or volunteering, especially in an activity that involves critical thinking and social interaction-both of which stimulate brain activity.

Ashton noted that some studies have shown that working later in life wards off cognitive decline. For every year that a subject worked, there was a seven week delay in the onset of Alzheimer's symptoms.

Ashton suggests mental challenges to stimulate brain activity as well, anything from learning a new language to playing and practicing a musical instrument.

To keep your brain functioning optimally, your body must keep up too. Exercise is key when it comes to maintaining high brain activity. Physical exercise helps your heart pump blood flow into the brain. Studies have shown that biking, running, swimming, walking, and lifting weights at least once a week can help prevent cognitive decline in people who were middle-aged or older.

Naturally, your diet matters too. A study consisting of over two thousand older adults found those who ate a Mediterranean style diet that consists largely of nuts, fruit, fish, and low-fat dairy products, were less likely than others to develop Alzheimer's disease.

Protect yourself from brain drain by getting the right amount of sleep nightly. Sleep deprivation can hurt your brain. Your brain needs sleep to regenerate neurons within the cerebral cortex while other stages of sleep can for forming new memories and generating new synaptic connections. Sleep deprivation may cause your speaking ability to deteriorate. When you're overly tired, you may find yourself using repetitive words.

Chronic stress also affects the structure of the brain and function of the brain. In healthy people, chronic stress can disrupt creativity, flexible problem solving and your working memory.

Excessive alcohol use can harm the brain and have a large impact on the cerebral cortex-the part of our brain mostly responsible for higher brain functions like problem solving and decision making. It also makes a significant impact on our hippocampus (important for memory and learning) and our cerebellum (our movement coordination).

So, no more senior moment excuses -- your brain may be better now than ever.

Aging and longevity linked to specific brain region in mice

In a study on mice engineered to produce a protein showed that a specific brain region, called the hypothalamus governs aging and longevity.
The researchers found that mice engineered to have their brains produce more SIRT1, a protein known to play a role in aging and longevity, tend to be more active after a two-day fast than those who don't produce the protein.
They explained that the mice with increased brain SIRT1 have internal mechanisms that make them use energy more efficiently, which helps them move around in search of food even after a long fast.
This increased energy-efficiency could help delay aging and extend lifespan.
"This result surprised us. It demonstrates that SIRT1 in the brain is tied into a mechanism that allows animals to survive when food is scarce. And this might be involved with the lifespan-increasing effect of low-calorie diets," said the study's senior author Dr. Shin-ichiro Imai, an expert in aging research at Washington University School of Medicine in St. Louis.
Imai's past research demonstrated that SIRT1 is at the center of a network that connects metabolism and aging. A form of the gene is found in every organism on earth.
The gene coordinates metabolic reactions throughout the body and manages the body's response to nutrition. SIRT1 is activated under low-calorie conditions, which have been shown to extend the life spans of laboratory animals.
The researchers found that the key to the mice's extra activity lies in a small region of the brain called the hypothalamus, which controls basic life functions such as hunger, body temperature, stress response and sleep-wake cycles.
"This is the first time that it has been demonstrated that SIRT1 is a central mediator for behaviour adaptation to low-calorie conditions," said a co-author of the study.
The study suggests that the brain, and particularly the hypothalamus, might play a dominant role in governing the pace of aging.
They believe their studies could eventually provide clues for increasing productive aging in people.
"If we can enhance the function of the human hypothalamus by manipulating SIRT1, we could potentially overcome some health problems associated with aging. One example is anorexia of aging in which elderly people lose the drive to eat. It is possible that enhancing SIRT1 could alleviate behavioral problems like this," said Imai.

A brain disorders battle

THIS WEEK’S 20th anniversary of the American with Disabilities Act illustrates the progress our country has made in advancing accessibility and independence for those who face physical challenges every day. The law protects Americans from being discriminated against because of their physical challenges. Now, we must turn our focus to helping those with brain disorders.

Approximately 100 million Americans have some form of traumatic brain injury, including an increasing number of veterans returning from the wars in Afghanistan and Iraq. Millions more suffer from Alzheimer’s, autism, Parkinson’s, and epilepsy.

Our nation’s economic burden of these brain-related illnesses is more than $1 trillion each year in lost wages, lower workplace productivity, and health care costs, yet less than 5 percent of the National Institutes of Health budget goes to neuroscience.

We lack the coordinated leadership and urgency to fight these diseases that impact too many families. The status quo is simply unacceptable. But we are at a unique moment when we can tap Washington’s political will to come to the aid of veterans with scientific possibilities for medical breakthroughs, and help all Americans suffering from brain disorders.

This effort requires us to bring the same kind of urgency to the fight as we did with AIDS. We must be of one mind when it comes to brain research, and not silo the research among various brain disorders. What this requires is that we get behind the translational research efforts currently underway at the Department of Defense and the Veterans Administration and make the veterans’ cause the cause of all those suffering from a brain-related disorder.

For many the notion of research and science seems distant to their daily lives. But to the family whose parent is losing his or her memory to Alzheimer’s, science becomes very personal.

For the parents of a child with autism, the neuroscientist who helps their child regenerate their neuropathways of cognition is as personal as it comes.

And for the veteran who is paralyzed by a spinal cord injury, the neuroscientist who discovers how to use stem cells to reconnect the veterans brain with the rest of his or her body is their “first responder.’’

For me, as I approach the one-year anniversary of the death of my father, Edward M. Kennedy, as a result of a brain tumor, I mourn his passing but also marvel at the fact that thanks to a neurosurgeon, I was given an extra year with my father beyond what anyone had predicted. To me, that is personal. To me, science is a means to an end — which is to protect the ones we love and to be sure we are doing everything we can to realize medical breakthroughs and cures.

That is the heart of the question. Are we doing enough to make these cures a reality as fast as we can?

As we celebrate the most recent iteration of the civil rights struggle, the 20th anniversary of the Americans with Disabilities Act, it would be appropriate to reflect on the original struggle for civil rights and the national address given by a young president who asked, “Who among us would then be content with the counsels of patience and delay?’’

Mind meld: Brain cells synchronize during good conversations

Proceedings of the National Academy of Sciences, Princeton
Shades of Mr. Spock -- our brain cells really do "mind meld" during intense communication, suggest psychologists.In the Proceedings of the National Academy of Sciences journal study, a team led by Princeton's Greg Stephens looks at functional magnetic resonance imaging brain scans of people involved in unrehearsed, real-life stories. "To make the study as ecologically valid as possible, we instructed the speaker to speak as if telling the story to a friend," says the study.
Following the brain scans of the conversations, the researchers asked the listeners to fill out a questionnaire detailing their comprehension of the story. Remarkably, the scans show similar areas of the brains of speakers and listeners firing, with a slight lag for the listener, during more effective conversations. Further, some listener's brain cells fired up in some brain regions ahead of the speakers, indicating they were predicting where the story was headed, says the study:
"The findings shown here indicate that during successful communication, speakers' and listeners' brains exhibit joint, temporally coupled, response patterns. Such neural coupling substantially diminishes in the absence of communication, such as when listening to an unintelligible foreign language. Moreover, more extensive speaker–listener neural couplings result in more successful communication. We further show that on average the listener's brain activity mirrors the speaker's brain activity with temporal (time) delays. Such delays are in agreement with the flow of information across communicators and imply a causal relationship by which the speaker's production-based processes induce and shape the neural responses in the listener's brain."
The findings add weight to animal studies showing "mirror" neurons, or brain cells, firing up when creatures observe one another, suggested by some as the starting point for empathy in the human brain. "Further understanding of the neural processes that facilitate neural coupling across interlocutors may shed light on the mechanisms by which our brains interact and bind to form societies," says the study.

Scientists find gene that causes Parkinson's disease

Scientists have identified a gene responsible for developing Parkinson's disease, a discovery that could lead to new ways to treat the degenerative disorder. Researchers at Stanford University, California, found a molecule, called micro RNA, which causes the death of nerve cell in the brain,
triggering Parkinson's disease.

Describing their discovery as a "significant step forward" in the battle against the degenerative disease, the scientists said it would pave the way for new drugs that could block the molecule's action in its tracks.

Parkinson's is a progressive neurological condition resulting in tremor, difficulty in moving and loss of balance that's usually diagnosed after the age of 60, although one in twenty sufferers are under forty.

A person with Parkinson's will only develop symptoms once around 80 per cent of these cells are lost, so they may have had the condition for some time before problems come to attention, the Telegraph reported.

The researchers, who carried our their study on common fruit fly Drosophila, found that the gene variant results in impaired activity of chemicals which fine tune protein production in cells.

Lead author Prof Bingwei Lu said, "Micro RNA, whose role in the body has only recently begun to be figured out, has been implicated in cancer, cardiac dysfunction and faulty immune response.

"But this is the first time it has been identified as a key player in a neurodegenerative disease."

The new findings, published in the journal Nature, showed how the mutation trips up normal activity leading to overproduction of at least two proteins that can cause brain cells to die.

Prof Lu and colleagues noticed that laboratory flies with the gene variant had high levels of these proteins after developing brain damage associated with Parkinson's.

And toning down the levels of these two proteins prevented the death of dopamine nerve cells in the flies.

'Miracle Baby:' Doctors Save Toddler Impaled in the Brain by Hook

The active 17-month-old baby squirming on his grandmother's lap outwardly shows no sign of the horrific brain injury that stunned the doctors charged with saving his life.

Doctors remove metal hook lodged two inches inside boy's brain.
Dubbed the "miracle baby," Jessiah Jackson is "in perfect shape," after doctors removed a hook that was embedded two inches into the little boy's brain.
"In this particular case so many things had to be done properly," said Dr. Anand Germanwala, chief of skull-based neurosurgery at North Carolina Children's Hospital, where Jessiah was treated. "And they were."
But the injury was a terrifying one. On July 17, Jessiah was sitting in a chair in his family's backyard when he reached for a sippy cup that had fallen off his chair. The boy tipped backwards, tumbling off the side of the porch.

He landed headfirst on top of a pressure washer and a hook from the machine jammed into his head, coming to a stop just short of the brain's main blood vessel. A puncture to that vessel would have been a fatal injury.

"He was crying and I was trying to make sure he didn't move," said Carlton Redd, an uncle who saw Jessiah fall.

Quick-thinking neighbor Lavern Nobels, a former volunteer firefighter, ran to help and sawed through the metal pipe to free Jessiah from the pressure washer.

"I went down by his shoulder blades and I cut through the bar this way, away from him," she said.

Jessiah was airlifted to a hospital in Wilmington and then to the children's hospital in Chapel Hill. Though doctors are monitoring him carefully for infection, he is not expected to suffer long-term complications.

"Everyone is calling it a miracle because he came through this," his grandfather and legal guardian Joseph Jones told "Good Morning America," as Jessiah sat next to him on his grandmother's lap. "And not only came through it, he's up, alert and back to his old self to where he was before the accident."

"With the help of the good Lord and Dr. G, he's a miracle," Jones said.

Photo: Boy with metal rod in brain

Seventeen-month-old Jessiah Jackson had an 'L'-shaped metal rod lodged in his brain after an accident. Surgery to remove the rod was successful, and the toddler shows no signs of brain damage from the incident.
(North Carolina Children's Hospital, Chapel Hill)

Germanwala said Jessiah was lucky to have so many quick-thinking adults tend to him before emergency workers arrived. His aunt and uncle area both EMTS. Once at the hospital, surgeons discovered the hook had actually made a 90-degree turn in his brain.
Germanwala said he had to use his hands to remove the hook.

Just Buy It: Impulsiveness Tied To Brain Chemical

Joshua W. Buckholtz and David H. Zald This composite image of brain scans shows two traits of a highly impulsive individual. The cool colors in the midbrain are indicative of a decrease in dopamine receptor levels while the warm colors show elevated levels of dopamine in a different part of the brain called the striatum.

It's late at night and you're watching TV when an infomercial comes on. You don't need a food dehydrator, but there's a part of you that wants it anyway. You look at your phone.
What happens next may come down to how impulsive you are. Impulsiveness is about more than shopping — impulsive people are vulnerable to substance abuse and some forms of mental illness.
Joshua Buckholtz, a researcher at Vanderbilt University in Nashville, Tenn., thinks that the brains of impulsive people have too much dopamine. Dopamine is a chemical involved with many different brain functions, but in this case researchers are interested in drive. They believe high levels of dopamine are causing some individuals to behave rashly, perhaps by buying a food dehydrator they don't need.
To understand how dopamine could lead to impulsive behavior, Buckholtz and the Vanderbilt group looked at the midbrain, the lower-middle bit of the brain. The midbrain produces dopamine and pipes it out to other regions, where it creates the drive to get the things you want. Normally, sensors in the midbrain called autoreceptors keep dopamine at the right level.

"You can think of it as very similar to how a thermostat works," Buckholz says. In your house, the thermostat will tell your furnace to produce more heat or shut off, depending on the temperature. Similarly, the autoreceptors tell the midbrain to start pumping dopamine or stop, depending on how much of the chemical is already around.
The Vanderbilt researchers suspected that the dopamine thermostats of highly impulsive people are broken. To find out, they took 32 healthy volunteers with varying levels of impulsivity. They scanned their heads and found that on average, impulsive people had fewer thermostats. To test the idea still further, the team gave volunteers a drug that releases dopamine, then scanned their brains again.
"The people who scored highest on our trait measure of impulsivity had upwards of four times the amount of dopamine released," Buckholtz says.
But some researchers believe that there's more to impulsiveness than the dopamine thermostat. "This is not a very huge effect," says Ahmad Hariri, a professor of psychology and neuroscience at Duke University. He thinks that other brain chemicals with their own thermostats also play a role.
"I think that there is a circuitry of self-control that's fundamental to many, many aspects of living," agrees Edythe London, a psychiatrist at UCLA. London says that understanding the dopamine thermostat and others may eventually lead to treatments for addiction and attention-deficit hyperactivity disorder. Those treatments might be drugs, or they might be new therapies that reinforce the thermostats and improve their performance.
London adds that the goal isn't to get rid of impulsiveness all together. "Too much self-control thwarts creativity," she says.