Teaching about the teenage brain

What do we know about teenage brain development?

Until recently it was assumed that there was little further development in the brain after the end of childhood. However we now know that the brain continues to change and develop all through adolescence. In fact, there is more change in the brain during adolescence than at any other time in human development apart from the first three years of life.

The maturation of the brain allows for new learning and the development of new intellectual skills. In addition the bridge between the two halves of the brain strengthens, allowing for greater connectivity, and enabling the brain to use its capacity better.

What are synapses?

The brain consists of billions of cells, and these are connected by nerve fibres. The nerve fibres connect each nerve cell (or neuron) to others, but there is a tiny gap, called the synapse, between one nerve cell and another. This is important, because in that gap (synapse) there are chemicals (neurotransmitters, or chemical messengers) which either help or hinder the impulse passing along to the next neuron.

What is neural pruning?

A further change that occurs in late childhood is a significant increase in the amount of grey matter. This is the area of the brain where most of the nerve cells are to be found. The grey matter is then gradually reorganised and re-arranged during the teenage years.

The networks of cells that are useful are reinforced, and the networks that are of little use are allowed to die away. This process is known as pruning. The phrase “use it or lose it” is used to indicate that connections between cells that are valuable should be developed and rehearsed during this time, to avoid being disregarded.

What is myelin formation?

The material that encases the nerve fibres – called myelin – is strengthened during the teenage years, so that impulses can travel faster and more effectively around the brain.

How are teenagers’ brains affected by hormones?

It has always been known that teenagers are affected by their hormones. This upset in the hormone balance is often seen as an explanation for moody or irritable behaviour. What is new in our knowledge is that the balance of hormones affects brain development.

Surges of these hormones may encourage teenagers to seek out emotionally charged experiences, or to look for novelty and excitement. It is worth noting that levels of hormones such as cortisol and serotonin fluctuate considerably during this period. The release of cortisol is linked to experiences of anxiety, whilst serotonin helps moderate anxiety. If these hormones are in flux it will be apparent that emotions may be difficult to manage.

Lastly it is important to mention dopamine. This is a hormone which is released when we get pleasure or enjoyment from an activity. The brain is particularly sensitive to dopamine during the teenage years, and some risky or thrill-seeking behaviours can be explained by increased dopamine activity at this time. Heightened levels of dopamine, and the effect of this on the pleasure centres, may have the effect of leading some teenagers to seek thrills and pleasure, without having taking into account what may happen as a result of these activities.

How can we encouraging healthy brain development?

As teachers, we need to show awareness and understanding. If we can make allowances for the fact that teenagers are experiencing a major upheaval and readjustment of their brains, this will make relationships easier and contribute to wellbeing.

A good balance of hormones is also essential if the brain is to manage the process of pruning unwanted connections, whilst developing and cementing useful neural pathways. If the young person experiences too much anxiety or stress the hormone balance will hinder this fundamental process. There is no way to avoid some degree of anxiety and stress, but it’s important to try and help students keep this to a reasonable level and help them learn how to manage these difficult emotions.