Tuesday, 18 September 2007

When the silverfish start to dance...


A SMUDGE on the car windscreen won’t go away.
A squirt of water and quick flick of windscreen wipers makes no difference, neither does a firm, fast rub with a cloth on the inside glass.
Damn. The smudge has become a silverfish that slips out of sight.
Within minutes it’s joined by a line of quicksilver critters doing a zigzag dance in the peripheral vision of the driver’s eyes.
Slow-moving commuter traffic becomes a terrifying distortion of movement and flashing metal. So, with exaggerated care, the young woman noses her car to the side of the motorway and waits until a policeman finds her slumped over the steering wheel, hands covering light-sensitive eyes.
I got a police escort that day more than 20 years ago, because the man in blue knew what was going on in my head.
He was a migraine sufferer too. We are among 400,000 New Zealanders affected by this neurological disorder.
Of those sufferers, called migraineurs, 300,000 are women. The 3:1 ratio can possibly be blamed on hormone irregularities, which are listed among the triggers for this invisible illness.
Lack of sleep, stress, relaxation after stress, fatigue, overuse of over-the-counter pain relievers, irregular exercise, bright lights and smoke are named as other possible migraine starters. So is diet, including cheese, red wine and yes, coffee. Double damn.
While there are hundreds of research programmes going on around the world, scientists have yet to locate the definitive cause of this often debilitating disease.
“It is thought a migraine attack is triggered within the brain itself,” says the National Headache Foundation, in the United States.
The foundation says that once an attack begins, it is believed the pain and other symptoms of migraine stem from an inflammatory process.
This may be caused by an interaction between the trigeminal nerve (the fifth cranial nerve responsible for sensation in the face) and blood vessels in the coverings of the brain.
The brain chemical, serotonin, is linked to this inflammation, but its role is not yet clear.
Scientists in Japan are studying this connection.
While researchers have yet to pin down the underlying culprit, or culprits, there is no doubt it’s painfully real for the afflicted.
“Migraine is a legitimate, biological disease characterised by throbbing head pain, usually located on one side of the head, often accompanied by nausea and sensitivity to light and/or sound,” the American foundation says.
“Migraine is more common than asthma, diabetes or congestive heart failure,” its website says.
Similar information is echoed throughout the internet, including on the Neurological Foundation of New Zealand’s site.
“Though the causes are not precisely known, it is clear that migraine is a genetic disorder,” it says.
Global research isn’t good news for children of migraineurs. If one parent is a sufferer, there’s a 50% chance their children will also be afflicted. But if both parents get migraines, there’s a 75% probability their kids will inherit the illness.
The highest incidence of migraine occurs in both men and women aged between 20 and 45, but even toddlers can get migraines.
In fact children can get stomach migraines, which present as severe tummy aches.
Among all sufferers, only about 20% of people experience visual disturbances that herald the onset of a pounding head. This telltale sign is called a migraine aura.
People may see light flashes, blind spots, shimmering lights, or zigzag lines.
Or a smudge on a windscreen that turns into silverfish…

Unlocking the migraine puzzle

AN Auckland University scientist is trying to unlock the key to migraine treatment.
Senior lecturer Dr Debbie Hay is leading a study into a group of molecules believed to play a role in the painful illness.
Dr Hay, from the university’s School of Biological Sciences, uses a lock-and-key metaphor to explain the basis of her study and how it is opening the door to migraine knowledge.
The key is a hormone called calcitonin gene-related peptide (CGRP), which is found in people’s nerves.
“People who have migraines have more of this in their blood,” she says.
This hormone fits into a lock, called a receptor.
When this happens, it causes blood vessels to open up. In medical terms, the hormone is a naturally occurring vasodilator. Migraine pain is thought to be caused by blood vessels in the brain opening up, allowing more blood to flow through them.
“That’s one of the reasons we think CGRP might be involved in migraines,” Dr Hay says.
But she is frank about scientists’ knowledge of the hormone’s role in migraines. “We don’t know if it’s causative or part of the process.”
In fact, the hormone is proving a bit of a mystery. “We don’t know exactly why we have it…we don’t know its true function yet. We know it has this relationship with migraines.”
Clinical trials overseas have shown that a new drug, which prevents the key fitting into the lock, or the hormone activating the receptor, is effective in treating migraines.
“The problem is that it has to be given by injection, which is not ideal,” Dr Hay says.
“We need to be able to design a better drug.”
This is where her research programme comes in. “I’m working very much at the molecular level to see how this drug interacts with the receptor so we might be able to design more useful drugs.”
a $492,000 biomedical grant from the Health Research Council of New Zealand is funding the three-year Auckland study.
“It’s an ongoing thing – it contributes to the global drug discovery process.”
Dr Hay says her work does not involve human samples or clinical trials, but she does consider the reality of her research. “I know people in the building who have migraines and I’m always very interested in them; it’s always important to talk to the end user.”

Sunday, 16 September 2007

FREAKY FACTS... A pain in the head

1) The World Health Organisation ranks migraines in the top 20 of disabling medical conditions.
2) Botox treatment for frown lines may also help prevent migraines, according to a case report in Auckland.
3) Migraines cost the American taxpayers $US13 billion ($NZ18.4b) in missed work or reduced productivity annually.
4) Spanish researchers have found that treating inflammation in the eye’s trochlea tendon can relieve migraine pain.
5) Famous migraineurs include Elvis Presley (right), Albert Einstein, Julius Caesar, Joan of Arc, Cervantes, Pascal, Nietzsche, Robert E. Lee and Karl Marx.

Tuesday, 11 September 2007

Exercise key to fit brain, body

MEDICAL research keeps proving a phrase that’s become a cliché – use it or lose it.
And eat a healthy balanced diet.
It may not be rocket science, but it is brain science.
“It’s the same old message really,” says David Bilkey (right), of Otago University.
“We know exercise has been shown to promote neurogenesis, the growth of new neurons in the brain.”
Mental exertion is just as important.
The associate professor of psychology says that that studies show that people with higher education are less likely to be affected by Alzheimer’s, a disease that destroys the brain.
People who have studied or regularly “work” their brains make more synapses or connections in the brain,
Dr Bilkey says. “That reduces the chances of damage, or makes it (the brain) more resistant to damage.”
As we age, our brain plasticity, or flexibility to make new connections, lessens. When we’re young, especially prior to the age of five or six, and again at adolescence, our brains make and remake a huge number of connections.
Higher education promotes even further connections, Dr Bilkey says.
Imagine the connections as streets in a village, one that eventually becomes a massive city. That’s how the brain works.
So, people who continue to use their brains, train their minds, and keep learning, will end up with a brain resembling a metropolis with an intricate network of highways, main roads and side streets.
“As we age, we are losing connections between neurons and the ability to alter those connections, so we are having to work with fewer resources.”
So you might lose a few hundred motorways and a couple of thousand cul-de-sacs, but when you’ve got millions of others still firing the messages around, it’s not such a big loss.
But if you’re a village it’s not so good.
So, let’s head back into the big city; this time London.
Dr Bilkey, who specialises in location memory, is interested in the outcome of a study on taxi drivers in the British capital.
It shows that cabbies who have been on the job for a long time and who know how to navigate London with ease, have bigger brains. “The longer you work as a taxi driver, the larger your hippocampus is,” he says, about the area of the brain first affected in Alzheimer’s patients.
The size increase is simply because the cabbies have an improved capacity to remember information about locations and navigation.
Birds who cache their food in many different places, which they later must return to, also have increased brain size in the part equivalent to the human hippocampus, Dr Bilkey says.
He believes people need to think of their brain as being a muscle. “If you use it, it will get larger and better, and if you don’t, it will atrophy.”
Muscles also waste away when they’re not used – as many people who’ve had a limb in plaster will know.
The same happens to anybody who doesn’t exercise, especially ageing people who decide they’re too old to keep going.
Garth Gilmour (right), a former journalist and the author of 21 books on sportspeople and fitness, implores people to keep going.
His big message is this: “The exercise you do should be will within your abilities to do and you need to enjoy it.”
He recommends walking, doing housework and gardening as simple ways to remain fit. “Stay away from gymnasiums,” he says.
But always head for steps. “My wife and our love our stairs,” he says, citing why he keeps living in a two-storey house, while other elderly people opt for units and no gardens.
The never-retired writer says using your brain is just as important as a physical work out. He tells people to read, do crosswords or other puzzles, plus talk and listen to people to remain mentally agile.
“Keep the mind moving, but sitting up, blobbing in front of the television isn’t exercising your brain. You are being dumbed down by TV.”

Keep going to keep on going

GARTH GILMOUR needs a holiday.
For the past few years the former journalist has been working on two books at one time, both with and about Olympic gold runner and scientist Peter Snell, who was born at Opunake.
Instead of taking time out, Gilmour is painting the inside of his Milford house.

He also mows the lawns of the large section and cuts the hedges, works in the garden and skips up and down the stairs of the two-storey home he shares with his fit wife, Kay.
His exercise of choice is cycling. For years he jogged great distances, but in his own words: “I have knackered knees from my late and overenthusiastic running burst…”
He has a bike for long rides in the open air, and one inside set on rollers for days when the great outdoors is unappealing.
You see, he is a man who acts on what he says, sagely, following the advice and information laid out in Use It or Lose It, the science book he co-wrote with Snell.
The book’s sub-heading says: Be Fit, Live Well – Keys to Successful Ageing for Men and Women.
This is the second edition of Use It or Lose It, first published last year. The new version will include information about the benefits of the fatty acid, Omega 3.
Its relaunch coincides with the release of Peter Snell – From Olympian to Scientist, destined for bookshops in November.
In December, Gilmour turns 82. “It’s just a number – it just gets a bit bigger each year.”
This is his second double.
He began is book-writing career working on No Bugles No Drums (about Peter Snell) and Run For Your Life (with running coach and jogging guru Arthur Lydiard, pictured with Gilmour left), both released in 1965.
The new Snell biography condenses the earlier book, and also tells the story of a boy who failed at school but ended up with a PhD in exercise physiology.
Snell has now been awarded a post-doctoral fellowship at the University of Texas Southwestern Medical Centre in Dallas, where he is an associate professor and director of the human performance laboratory.
He’s also a long-time orienteering runner and, of course, champion.
The secret to both men’s success is simple – don’t even think about stopping.
But I think Gilmour deserves a holiday.

FREAKY FACTS...Ticking time bombs

1) We all have our own ticking time bombs. Human cells contain telomeres, which hold the vital genetic information needed to continue cell activities. Our cells also produce telomerase, an enzyme that repairs damaged telomeres. But this stops in later life, killing most of us in our 70s and 80s.
2) You don’t have to be a born genius to become one. American educator Benjamin Bloom carried out a study of exceptional people in many fields, which led him “to see great talent as less an individual trait than a creation of environment and encouragement”. He continues: “We were looking for exceptional kids and what we found were exceptional conditions.”
3) Writing linear study notes using a black or blue pen uses much less than half the capacity of our cerebral cortex, where our long-term memory is stored.
4) Listening to a talking book uses 80% more of our creative intelligence than watching television.
5) Each of the 10 billion neurons in the human brain has a possibility of connections of 1 with 28 noughts after it. If that’s what a solo neuron can do, the capacity of connections our brain can make, if written out, would be 1 followed by 10.5 million kms of noughts.

Monday, 3 September 2007

Dreams may hold key to memory transfer

IT’S 5am and I’m accessing a massive database including fresh information downloaded overnight.
For the past week, I have been transferring “need-to-know” stuff from temporary files into this database.
The transfer always happens in the deep, dark night.
For several hours yesterday, those temporary files were crammed with scientific research on the brain’s ability to learn, retain and retrieve information.
With ease, all that data is coming back to me now.
The interviews, the articles in magazines, online and in books, are all there waiting to be accessed.
All because I slept on it.
I am, of course talking about memory.
And yours – although what you choose to download won’t be the same as mine. Even if we watched the same movie or listened to the same piece of music, we would consciously and unconsciously store different information.
That’s why court witnesses almost always have different versions of the same event, even though they swear (on the Bible) that they are being honest and accurate.
While we may glean different information, we all go through the same memory transferral process.
This involves moving information from our temporary files, a kind of short-term memory stored in our hippocampus, to our massive neuro-database, called long-term memory found in our cortex.
To do this job, we need to sleep.
More specifically, we need to dream, says Otago University’s Anthony Robins (left).
Just exactly why we dream has been a puzzle to scientists, philosophers and great thinkers for hundreds of years.
Sigmund Freud believed dreams were our subconscious way of expressing fears and the suppressed sexual urges we prefer not to face or act on in waking life.
Robins has another theory, one he’s discovered because of memory loss.
The associate professor of computer science is a leading figure in the university’s Memory: Mechanism, Processes and Applications research team, made up of 30 academic staff and about 150 students.
This in-depth study, which encompasses many of the university’s departments, has been running for a decade now.
But the more Robins continues his research using artificial neural networks (ANN), built to simulate how our brains work, the more he believes he’s discovered something startling.
It’s this: When the artificial network is fed new data it deletes the old. This is called “catastrophic forgetting”.
However, when a “rehearsal” of that existing information is played through the network while new data is added, none of the old is lost.
But Robins realised that rehearsing or playing every piece of information stored in the network was impractical and meant having to have a second memory system.
So he tried another tack. “I have proposed a mechanism, pseudorehearsal, which is similar to rehearsal but does not require the storage and access of old information.”
To explain further, Robins uses a musical metaphor.
“The ANN (network) is like an orchestra that can learn lots of pieces – say 50 all at once. But if the orchestra learns another piece tomorrow, it forgets the first 50 pieces.”
But if the orchestra “jams” or “makes stuff up” in a pseudorehearsal of the old, it can retain music already learnt and add the fresh piece with no loss of information.
He surmises that brains have evolved to overcome the problem faced by the artificial network. This is where dreams come into play, because they are our own “pseudorehearsal” of stored information or our own jamming sessions. This explains why they are a bizarre mixture of fact and fiction.
“In order to learn new things, the brain has to have the time to jam and to wander randomly over bits and pieces of old information or made-up fantasy stuff,” Robins says.
Another piece of information Robins has learnt from his research is that recollections are not set in stone.
“Memory is not based on any one fixed structure – it has to keep re-encoding itself,” he says.
Every time we access a memory, we are re-recording it. “A memory is a piece played live by an orchestra.”
That’s opposed to being like a digital or tape recording, which is the same every time it’s played. Think of a single you hear on the radio – often you see it performed live and it’s annoyingly or pleasantly different to the recorded version. The live version may be sung by the same person, but they often change a word here and there, add an extra emphasis on a note, or simply forget the lyrics and improvise. Also, the band may be different, because there’s a new lead guitarist or drummer.
“Our memories are houses of sand, not cement,” Robins says.

FREAKY FACTS... stuff to remember

1) If you’re one of those people who doesn’t recognise people in the street or can’t remember faces, there may be a scientific reason why. It’s possible that you suffer from what scientists call developmental prosopagnosia, or face blindness.
2) This could be a casino owner’s nightmare – a person who can memorise the order of an entire pack of freshly shuffled cards in less than 30 seconds. That’s what Ben Pridmore did at this year’s United Kingdom Memory Championships. He managed the feat in 26.28 seconds, beating the previous world record of 31.16 seconds.
3) The marathon version of the card-pack trick is even more mind boggling. In 2002, eight-times world memory champion Dominic O’Brien recalled 54 inter-shuffled decks of playing cards after only looking each of the 2808 cards once. But the Englishman did make eight mistakes, four of which he corrected himself after being told he was wrong.
4) A woman in her 40s is being studied by neurobiologists in California because of her near-perfect ability to recall nearly every detail in her life from when she was 18 months old. She can even remember things like the dates of every Easter going back to 1980 and what she did on those days.
5) Neurobiology scientists at Boston University believe they are close to cracking the memory code by reading the minds of mice. But unravelling human memory is some way off, but will be possible, if or when, non-invasive and highly sensitive monitoring instruments are developed.