Finding Pathways

Dr Maurice Curtis's office is—if one is brutally honest—a non-testament to his belief that humans should stimulate their brains. The walls are white, the shelves are virtually bare and his windows look out on nothing except row upon row of hospital windows.

A balcony, not accessible unless one goes to the ground floor, blocks the view of the street two floors below. He occupies this office alone, tucked in a corner of a building, virtually invisible to the world.

It's hardly an environment designed to stimulate brain activity.

He's young, and if he'd stuck to his career path, he'd be working as a radiographer.

Halfway through his training, though, he attended several neurology lectures and developed a fascination with the workings of the brain. Taking this interest a step further, he introduced himself to Professor Richard Faull at the Auckland (NZ) Medical School and expressed an interest in doing a Masters of Science degree.

Several months later, after completing his training in radiography, Professor Faull informed Curtis he'd been accepted into the Masters program.

“It wasn't until much later I realised how hard Richard had pushed to get me accepted,” Curtis says. “I had none of the requisite qualifications— the onus was on me to not disappoint him.”

Studying further, Curtis completed his doctorate in 2004. The findings from his PhD were groundbreaking.

He discovered that in human brains affected by Huntington's disease, there is a massive increase in the amount of new brain cell production as the brain attempts to repair itself.

These studies were published in a number of prominent journals and set the scene for much of the work that followed. In addition to receiving the University of Auckland's Best Doctoral Thesis Award, Curtis was also awarded a Wrightson post-doctoral fellowship from the Neurological Foundation of New Zealand, to work on stem cells in the brain at the University of Gothenburg with Professor Peter Eriksson in Sweden. And there, he made another astounding discovery.

human neuroblasts migrate

Science is a prestigious magazine. To be published in Science is exciting. To be the front-page feature is unlikely.

But the findings Curtis presented as a result of his work in Sweden were nothing short of incredible, and Science featured his research on March 2, 2007.

“The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone cells reach the olfactory bulb (OB) in rodents.

However, the RMS in the adult human brain has been elusive,” read the opening paragraphs. “We demonstrate the presence of a human RMS, which is unexpectedly organised around a lateral ventricular extension reaching the OB, and illustrate the neuroblasts in it. The RMS ensheathing the lateral olfactory ventricular extension, as seen by magnetic resonance imaging, cell-specific markers, and electron microscopy, contains progenitor cells with migratory characteristics and cells that incorporate 5-bromo-2-deoxyuridine and become mature neurons in the OB.”

There are too many big words but Curtis is good at plain English.

“Recently, we have learned that the brain can produce new brain cells,” he says. “The work done during my PhD showed that the number of new brain cells increases dramatically in response to a neurodegenerative event—such as Huntington's disease—and we think those cells migrate out toward the damaged area in an attempt to repair the damage.

“The research in Sweden resulted in the discovery of a pathway in the brain from the subventricular zone (the brain's maternity unit—where new brain cells are born) to the olfactory bulb (where smells are memorised).

The cells in the olfactory bulb are replaced every four to six weeks.

“We now have several new facts to work with,” Curtis says. “The brain does create new cells, the cells don't stay in the place where they were born and there is a recognised pathway. By studying the cells on the pathway, we are hopeful that we'll be able to eventually get more cells to move to specific [damaged] areas of the brain.”

growing more cells

“My brain cell has gone AWOL!”— it's a common enough saying, based on the now-defunct theory that the brain is unable to create new brain cells.

It is a relief to know the brain cells with which one was originally blessed aren't the be-all and end-all of brain cell development. New brain cells are made—and Curtis believes we can help the process along.

“Little kids are exposed to lots of new environments,” says Curtis. “They are taken to the beach, to the zoo, to the playground, to the museum. They go to kindy or preschool or playgroup.

They visit grandparents, cousins and friends. Their environments are created to be stimulating—lots of bright colours, lots of new sounds, smells and experiences.”

All this is great—but it shouldn't end just because one has “grown up.”

“As we age, less emphasis is placed on exposure to new environs,” Curtis explains. “We have our friends, we have our jobs and we are busy in our daily routines. Essentially, the older we get, the less we stimulate our brains with new experiences. When our brain is not stimulated enough, cells don't survive as long and spatial memory decreases.”

Stimulating the brain causes the little gray cells to proliferate. Visiting friends, meeting new people and doing group activities will improve brain health.

Physical exercise—running, walking, cycling, swimming—all make a positive difference. Playing games that exercise the memory, doing crosswords, jigsaw puzzles, sudoku and brainteasers all help the brain function at its best.

“The best things for improving brain health,” says Curtis, “are meeting new people, visiting museums and doing memory exercises.”

alcohol and new brain cells

Curtis says “there have been some profound studies done that show the production of new brain cells is inhibited dramatically by the consumption of alcohol. It has been shown numerous times that the production of new brain cells is pretty much eliminated if you consume alcohol. It's potentially more damaging if you binge drink. The regular consumption is bad but binge drinking is even worse.”

room for God?

Is there room for God in this world that Curtis works in? As a Christian and a scientist, Curtis thinks there is but he's careful not to make his scientific life subjectively based on his belief in God. Looking for ways to treat brain disorders doesn't rely on an evolutionist or creationist viewpoint but rather, on a knowledge of the brain.

“Many evolutionists look into nature and try to prove a lack of a God. It clouds their judgement when they try and do science,” he says. “At the end of the day, if you want to make a call on what's happening in the brain, you don't need to have a deep theory on how God works in order to derive how this neuron is connected to that neuron.

“But I definitely think the intricacy and the complexity of the brain, the number of connections and networks, and the tiny components in each cell certainly make you think it wasn't a chance happening. Basically, a neural network on each cell—more complicated than the Telecom network in New Zealand—is at work in the brain and there are millions of these cells. I'm fairly hard-pressed to think of a way this could come about by chance.

“I definitely think philosophically about it but in terms of day-to-day work, I try not to project too much of the philosophy onto the science.”

moving up

Meanwhile, Curtis has good news about his hole-in-the-wall office. “It's temporary,” he says. “When the renovations upstairs are complete, I'll get a different office, closer to other people.”

Which is just as well, because the more effectively Curtis can apply himself to his science, the better it will be for the rest of us.