ADHD=NABC

ADHD brain chemistry clue found


Levels of ADHD have been rising
US researchers have pinned down new differences in the brain chemistry of people with attention deficit hyperactivity disorder (ADHD).
They found ADHD patients lack key proteins which allow them to experience a sense of reward and motivation.
The Brookhaven National Laboratory study appears in the Journal of the American Medical Association.
It is hoped it could help in the design of new ways to combat the condition.

For far too long there has been an assumption that children with ADHD are deliberately wilful
Andrea Bilbow
ADDISS
Previous research looking at the brains of people with ADHD had uncovered differences in areas controlling attention and hyperactivity.
But this study suggests ADHD has a profound impact elsewhere in the brain too.
Researcher Dr Nora Volkow said: "These deficits in the brain's reward system may help explain clinical symptoms of ADHD, including inattention and reduced motivation, as well as the propensity for complications such as drug abuse and obesity among ADHD patients."
The researchers compared brain scans of 53 adult ADHD patients who had never received treatment with those from 44 people who did not have the condition.
All of the participants had been carefully screened to eliminate factors which could potentially skew the results.
Dopamine pathway
Using a sophisticated form of scan called positron emission tomography (PET), the researchers focused on how the participants' brains handled the chemical dopamine, a key regulator of mood.
In particular they measured levels of two proteins - dopamine receptors and transporters - without which dopamine cannot function effectively to influence mood.
ADHD patients had lower levels of both proteins in two areas of the brain known as the nucleus accumbens and midbrain.
Both form part of the limbic system, responsible for the emotions, and sensations such as motivation and reward.
Patients with more pronounced ADHD symptoms had the lowest levels of the proteins in these areas.

It suggests that teachers need to make sure that school tasks are interesting and exciting, so that children with ADHD are motivated to remain interested
Professor Katya Rubia
Dr Volkow said the findings supported the use of stimulant medications to treat ADHD by raising dopamine levels.
The findings also support the theory that people with ADHD may be more prone to drug abuse and obesity because they are unconsciously attempting to compensate for a deficient reward system.
Andrea Bilbow, of the ADHD charity ADDISS, said the study might help convince people who argue that ADHD is more to do with bad parenting than any concrete medical difference.
She said: "The findings of this new research will go a long way to helping us understand the presentation of symptoms but more importantly it may give teachers more of an idea of what interventions should be used in the classroom in order to accommodate children with ADHD.
"For far too long there has been an assumption that children with ADHD are deliberately wilful which has led to mismanagement and ultimately permanent exclusions from school."
Professor Katya Rubia, of London's Institute of Psychiatry, said: "This study widens our horizons. It shows that ADHD is not just about abnormalities in the attention systems of the brain, but also abnormalities in the motivation and emotion centres.
"It suggests that teachers need to make sure that school tasks are interesting and exciting, so that children with ADHD are motivated to remain interested."




//////////////////Irlen Syndrome is a possible explanation for the average to gifted
student who avoids reading or cannot read and for the
learning-disabled student who struggles with reading. Helen Irlen, a
school psychologist, worked with college students with reading
difficulties. The students had average to above-average intelligence.
They reported symptoms that occurred when reading that no one had
identified before such as: migraines and headaches, falling asleep,
words switching around, print moving or vibrating, the text becoming
3D, the brightness of the page hurting their eyes, print becoming
blurry, and words blending into each other. Irlen found that placing
colored overlays over the reading material improved the student's
comprehension, fluency, comfort, and attention.




/////////////////////Severed Lizard Tail Has a Mind of Its Own
By LiveScience Staff
posted: 09 September 2009 07:10 am ET
Buzz up!
Comments (20) | Recommend (6)

The tail of a leopard gecko (Eublepharis macularius), has a mind of its own. Once shed from the lizard's body, the tail completes complex jumps and lunges. Credit: Tim Higham
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It's amazing enough that lizards can shed their tails as a decoy for predators and entertainment for young boys. But a new study of geckos documents an incredible set of acrobatics that these severed tails perform.

Though it might seem as though a lizard loses its tail because it's pulled off, in fact the lizards control the severing, apparently when they sense they're about to become dinner.

The tails exhibit not only rhythmic but also complex movements, including flips, jumps and lunges, after the tails are shed, Anthony Russell of the University of Calgary and Tim Higham of Clemson University report in the journal Biology Letters.

No previous study had quantified movement patterns of the tail by examining the relationship between such patterns and muscular activity.

The new study shows that the signals responsible for movements of the shed tail begin at the very far end of the tail, in a portion of the spinal cord, indicating that there is a control center located there that is likely overridden by higher centers until the tail is shed, at which point its circus-like performing potential is realized.

The findings suggest a model for studying the complex functions of the human spinal cord and the effects of spinal cord injuries.

"Much is known about the ecological ramifications of tail loss, such as distracting predators, storing energy reserves and establishing social status but little is known about the pattern and control of movement of automized gecko tails," Russell said. "What we've discovered is that the tail does not simply oscillate in a repetitive fashion, but has an intricate repertoire of varied and highly complex movements, including acrobatic flips up to 3 centimeters [1.1 inches] in height."

But how?

"An intriguing, and as yet unanswered, question is what is the source of the stimulus that initiates complex movements in the shed tails of leopard geckos," Higham said. "The most plausible explanation is that the tail relies on sensory feedback from the environment. Sensors on its surface may tell it to jump, pivot or travel in a certain direction.

Another idea is that multiple networks of neurons in the tail's spinal cord fire at different times, causing these outbursts of complex activity.

And why?

The tail tumbles could serve as first-rate decoys.

"When the tail is doing flips and everything else that could enhance the distraction of the predator so the lizard can get away. If the tail moves in a really complex way, the predator would try to get the tail and when it can't get it, would go away," Higham told LiveScience. "Then the lizard could come back and eat the tail." That way, the lizard could gain back energy lost when shedding its tail, which stores a lot of fat, he added.





////////////////////Blacksmiths In 70,000 BC?Early modern humans living on the southern Africa coast employed pyrotechnology, the controlled use of fire, 72,000 years ago, to increase the quality and efficiency of their stone tool manufacturing process, according to a report in Science.The international team of researchers deduces that "this technology required a novel association between fire, its heat, and a structural change in stone with consequent flaking benefits." Further, they say their findings ignite the notion of complex cognition in early man.If their findings hold up, it could mean humans' ability to solve complex problem




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