Neuroscience research
got a huge boost last week with news of Professor John O’Keefe’s Nobel prize
for work on the “brain’s internal GPS system”. It is an exciting new part of
the giant jigsaw puzzle of our brain and how it functions. But how does cutting-edge
neuroscience research translate into practical advice about how to pass exams,
remember names, tot up household bills and find where the hell you left the car
in a crowded car park?
O’Keefe’s prize was
awarded jointly with Norwegian husband and wife team Edvard and May-Britt Moser
for their discovery of “place and grid cells” that allow rats to chart where
they are. When rats run through a new environment, these cells show increased
activity. The same activity happens much faster while the rats are asleep, as
they replay the new route.
We already knew that
the part of the brain known as the hippocampus was involved in spatial
awareness in birds and mammals, and this latest work on place cells sheds more
light on how we know where we are and where we’re going. In 2000, researchers
at University College London led by Dr Eleanor Maguire showed that London taxi
drivers develop a pumped-up hippocampus after years of doing the knowledge and
navigating the backstreets of the city. MRI scans showed that cabbies start off
with bigger hippocampuses than average, and that the area gets bigger the
longer they do the job. As driver David Cohen said at the time to BBC News: “I
never noticed part of my brain growing – it makes you wonder what happened to
the rest of it!”
Yet great
breakthroughs don’t automatically translate into practical benefits. “Research
may give us great insights, but we still can’t cure Alzheimer’s,” points out
neuroscientist Baroness Susan Greenfield. “And just because we know more about
what parts of the brain do normally, it doesn’t tell us why things go wrong. We
still need to know why special cells die in dementia. How come you can have a
major stroke with lots of neuronal damage, but not lose your memory? What is
the link between Parkinson’s disease and dementia?” In other words, why are
some cells damaged but not others?
Lab-based research is
key to piecing together the jigsaw of how our brains work and what goes wrong
when they don’t. Even scans or postmortem examinations of brains of people who
had dementia are of limited value, points out Greenfied, because “degeneration
starts 10-20 years before symptoms appear”. So what does neuroscience tell us
about keeping the brain fit?
Use it or lose it
It seems obvious that
the more you train, use and test your brain, the better it will perform. There
is some evidence that people with more education or skills have a lower
incidence of dementia. But the picture is complicated; perhaps highly educated
people eat better food. And more skilled people may be more likely to be in
work, benefiting from exercise, social interaction and mental stimulation. You
may build up a “cognitive reserve” while young, which gives you a headstart
over less educated people once dementia sets in. Staying physically, mentally
and socially active means that even if your brain scan looks as ropey as that
of a less active person, you will function better. No one can confirm the
benefits, but there is at least no downside to daily sudoku, crosswords,
reading, walks and talks.
Neuro-enhancing drugs
Nootropics are also
called smart drugs or cognitive enhancers. One of the best known is modafinil,
a “wakefulness-promoting” drug that stimulates the central nervous system and
is only prescribable in the UK for excessive daytime sleepiness (narcolepsy).
Whether it is much more effective than a strong cup of coffee remains
debatable, but its effect lasts longer. Modafinil is widely used by academics
and students because it makes people feel sharper and more alert. Professor
Barbara Sahakian of the University of Cambridge has found that sleep-deprived
surgeons perform better on modafinil, and thinks it may have a wider role in
improving our memory and mental function. “We found that modafinil improves
motivation and working memory in healthy people and makes doing tasks more
pleasurable,” she said. But long-term safety, especially for young brains, is
still not established. But for a lot of students, the question isn’t whether the
drugs are safe or constitute cheating, but how they can get hold of some.
Avoiding damage
Our environment is
full of neurotoxins that can interfere with the genes, proteins and small
molecules that build and maintain our brains. The younger the brain, the more
susceptible it is to neurotoxins. A paper by the US National Scientific Council
on the Developing Child says there are three types of neurotoxins that can
affect the developing brain: environmental chemicals such as lead, mercury and
organophosphates (pesticides); recreational drugs such as alcohol, nicotine and
cocaine; and prescription medications such as Roaccutane, used for severe acne.
Mature brains can be quite resilient, thanks in part to a barrier of cells that
restricts entry of chemicals from the bloodstream into the brain tissue. But
drugs, alcohol and cigarettes will poison even the most developed of brains if
you take enough of them.
Keep the blood
flowing
The brain needs a
good blood flow to deliver vital nutrients and oxygen and take away waste
products. Smoking, high blood pressure, uncontrolled diabetes, obesity and high
cholesterol all sludge up the arteries and impede blood flow. If you care about
your brain function, sorting out these risk factors remains the most useful
thing you can do.
Effects of diet
Omega-3 fatty acids,
antioxidants such as vitamins C and E, and vitamins B and D all have
neuroprotective effects, but trials have failed to show that high-dose
supplements of these individual nutrients will protect you from dementia.
However, eating a tasty Mediterranean diet that combines most of these
nutrients can’t hurt.
Future research
Professor Sahakian
has identified five areas of neuroscience research that will help our
understanding over the next five years.
• Smart and wearable
technology to monitor people’s brain health – similar to wristband monitors
that track heart rate.
• Brain scanning to
monitor changes in mental illness and track changes during treatments such as
CBT.
• Trials of
neuroprotective drugs such as solanezumab to prevent further deterioration in
patients with Alzheimer’s disease.
• Connectomics, the
study and production of connectomes – neural maps of the brain – will combine a
number of techniques to map and study connectivity in the brain.
• Genetics, to
understand the genetic mutations that contribute to autism and other
conditions.
• This article was
amended on 13 October 2014. An earlier version referred to Edvard and May-Britt
Moser as Swedish rather than Norwegian.
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