Tag: neuroscience

Exercise doesn’t just make you fitter – it makes you smarter too!

Exercise is important in keeping your heart and lungs healthy. We know for decades that the effort required in exercise allows life-giving oxygen to travel quicker and in greater amounts to all the tissues of the body – allowing the cells in them to grow and divide. A noticeable exception to this rule is the brain.

Neurons are different

Nerve cells or neurons are notoriously bad at dividing. Rather than divide, a neuron survives by making up to 10,000 connections to neighbouring neurons – and this is the key to how we learn and recall as memories are created and strengthened.  This compromise works well for the first four decades of life however by your 50’s a gradual loss of neurons and their connections starts to take it toll resulting in a noticeable reduction in cognition as we find it harder to remember, especially recent events. 

An unexpected finding

Recent scientific findings from Columbia University show that exercise is important in helping to reverse this age-related loss of neurons. In this study in a small group of middle-aged people, exercising just an hour a day, four times a week, for three months triggers the growth of new neurons – a feat which has previously proved almost impossible for neuroscientists to achieve using drugs. Neuroscientists are still working out the possible reasons why simple exercise is so powerful at triggering the birth of neurons but a clue may be that the brain is very well supplied by blood vessels needed to deliver the food and oxygen to help make and maintain the trillions of synapses in the brain. In fact the brain is one of the most oxygen-sensitive organs of the body. It receives 20% of the cardiac output and accounts for about 25% of overall resting oxygen consumption. In addition, the brain as a highly vascular organ is very sensitive to changes in blood perfusion. It seems the extra increase in blood perfusion and life-giving oxygen associated with exercise may invigorate the brain to such a degree that it starts to actually grow new neurons again.

Exercise is as important as drugs

The finding that exercise triggers the brain to grow new nerve cells is a truly stunning discovery that will have implications for public healthcare policies for an increasingly ageing population. In addition, new treatments for brain illness such as Alzheimer’s disease and head injury may involve a combination of different therapies such as medication, psychological therapies, social support, self-help techniques and now, most importantly exercise. This combined approach will treat the person as a whole, and marks the beginning of the journey back to wellness and a normal life.

So the message is simple –if you want to stay smart just get out there and exercise.

How to increase serotonin in the brain without drugs

Aerobic exercise has been shown to elevate mood

As a follow-on to my last post on depression, I would like to direct you to an article I have stumbled upon from the Journal of Psychiatry and Neuroscience (1) published in 2007.

Its primary focus is on individuals with a serotonin-related susceptibility to depression, and nonpharmacologic methods of increasing serotonin to prevent depression in those with such a susceptibility.

Nonpharmacologic methods of raising brain serotonin may not only improve mood and social functioning of healthy people — a worthwhile objective even without additional considerations — but would also make it possible to test the idea that increases in brain serotonin may help protect against the onset of various mental and physical disorders.

The article discusses four possible strategies that are worth further investigation:

1. Altering Thought Patterns

The idea that alterations in thought, either self-induced or due to psychotherapy, can alter brain metabolism is not new. Numerous studies have demonstrated changes in blood flow in such circumstances. However, reports related to specific transmitters are much less common. In one recent study, meditation was reported to increase release of dopamine.The study by Perreau-Linck and colleagues (2) is the first to report that self-induced changes in mood can influence serotonin synthesis.

2. Exposure to Bright Light

Bright light is, of course, a standard treatment for seasonal depression, but a few studies also suggest that it is an effective treatment for nonseasonal depression and also reduces depressed mood in women with premenstrual dysphoric disorder and in pregnant women suffering from depression.

3. Exercise

A third strategy that may raise brain serotonin is exercise. A comprehensive review of the relation between exercise and mood concluded that antidepressant and anxiolytic effects have been clearly demonstrated.

4. Diet

According to some evidence, tryptophan, which increases brain serotonin  is an effective antidepressant in mild-to-moderate depression. Further, in healthy people with high trait irritability, it increases agreeableness, decreases quarrelsomeness and improves mood. However, the idea, common in popular culture, that a high-protein food such as turkey will raise brain tryptophan and serotonin is, unfortunately, false. Another popular myth that is widespread on the Internet is that bananas improve mood because of their serotonin content. Although it is true that bananas contain serotonin, it does not cross the blood–brain barrier.

To read this article in full please click here.

1. J Psychiatry Neurosci. 2007 November; 32(6): 394–399.

2. Perreau-Linck E, Beauregard M, Gravel P, et al. In vivo measurements of brain trapping of α-[11C]methyl-L-tryptophan during acute changes in mood states. J Psychiatry Neurosci 2007;32:430-4.

Latest research from computational neuroscience

Another fascinating topic from the SFN Annual Meeting was the research being undertaken in the area of computational neuroscience.

Computational neuroscience is the study of brain function in terms of the information processing properties of the structures that make up the nervous system.

It is an interdisciplinary science that links the diverse fields of neuroscience, cognitive science and psychology with electrical engineering, computer science, mathematics and physics.

In an interview in the current edition of New Scientist, Professor Terry Sejnowski, head of the computational neurobiology lab at the Salk Institute in La Jolla, California, says some of the most intriguing results in computational neuroscience come from collaborations between modelers and experimentalists.

Professor Sejnowski and his research colleagues’ research in modeling signal transfer patterns throughout the brain has resulted in new techniques which make it possible to simultaneously record signals from many neurons. The sensitivity means scientists can for the first time, watch the output from a neuron spread through the brain.

Research has also found that neurons respond differently to different stimuli (for example, signals required to move a prosthetic arm can change when people are tired). This research will help improve brain-machine interferences such as prosthetic limbs and thought-controlled wheelchairs.

Early childhood experiences influence the brain for life

Among the hot topics of debate at last month’s SFN meeting was that of the developing brain and how early childhood experiences, whether good or bad, influence the brain for a lifetime. 

Regina Sullivan of New York University postulates that child abuse-related epigenetic changes, which alter the brain, are passed on to the next generation, perhaps explaining the cycle of abuse observed in many families. (The development and maintenance of an organism is orchestrated by a set of chemical reactions that switch parts of the genome off and on at strategic times and locations. Epigenetics is the study of these reactions and the factors that influence them.)

The primary evidence for stress-related changes comes from human brain imaging, which has uncovered brain differences between children with a typical childhood and those who suffer abuse.

However, work being done by Bruce McEwen, professor of neuroscience at Rockefeller University in New York, shows that the effects of childhood experiences such as neglect or abuse, can be reversed through interventions such as high-quality early care and education programmes.

Source: New Scientist

What can neuroscience teach us about teaching?

This Friday 3rd December, I am heading to an International Conference on Engaging Pedagogy (ICEP) in NUI Maynooth. This is an annual event that brings together researchers and practitioners in the field of third-level teaching in order to discuss means and methods of improving student engagement.

I am looking forward to presenting recent findings on how recent findings from neuroscience – the scientific study of the brain – impacts on education. You can view my abstract and those of the other presenters here.