Dr Thanh-Tam Pham - 29/11/2020
At birth a baby’s brain contains 100 billions neurons roughly as many nerve cells as there are stars in the Milky Way. The brain starts to form about 3 weeks after conception. As the neuron matures, more and more synapses are made. A foetus brain contains roughly twice as many neurons that it needs. As a normal part of brain development, any connections that are seldom or never used will be eliminated. Circuits that are often used will become permanent. If a child receives little stimulation early on, the synapses will not develop and the brain will make fewer connections. For example, amblyopia is reduced vision in one eye that is not adequately used during early childhood as a result of a difference in image quality between the 2 eyes such as in crossed eye or one eye is focussing better than the other. If the condition persists without early treatment, the brain
connection with the eye with bad quality image will shrink and the weaker eye may become blind.
Neuroplasticity is the brain’s ability to reorganize itself by forming new neural connections throughout life and pruning the synapses that are no longer necessary or useful. It was once thought that neuroplasticity only occurs during childhood but it is now proven in the last 30 years that the brain can be altered even through adulthood. However the developing brain has a higher degree of plasticity than an adult brain.
Neuroplasticity allows the brain to receive information and form appropriate adaptive responses to different stimuli in different parts of the brain including environmental, social, behavioural or pharmacological stimuli.
The importance of neuroplasticity.
Neuroplasticity is the ability of the brain to modify its connections or rewire itself to allow the development from infancy through to adulthood, to repair the damage to the brain from disease or injury and to restructure itself to adapt to the environment.
It is great that it helps the brain to recover from traumatic brain injury or stroke.
Because the brain can change, we can control and set the direction for these changes to make our life better by rewiring the brain to establish better habits to contribute to better health and success.
Stress and Neuroplasticity.
Stress and emotional trauma cause cortisol to be released and high levels of cortisol can cause brain cells to die and reduce the connections between the cells in certain areas of the brain.
The hippocampus is intimately involved with learning and memory and it is very sensitive to stressors. McEwen and colleagues are the first to describe that stress causes atrophy of the hippocampal neurons.
The amygdala, was known for emotional regulation and fear learning, has the opposite response to chronic stress. The dendrites become more prominent and robust predicting a greater likelihood of reacting badly and creating abnormally strong memory formation. This may play a role in post traumatic stress disorder. Those with a disregulated amygdala are more likely to go into rage.
The altered plasticity in response to chronic stress contributes to stress related psychiatric illnesses. In mental illness, it is thought that maladaptive plasticity occurs resulting in the persistence of depressive symptoms such as rumination. With therapy, it may be possible to reprogram the maladaptive behaviour and produce long lasting remission.
Reversibility of the structural and functional plasticity has been demonstrated in response to pharmacological treatment with antidepressants and in behaviour therapy.
How to improve neuroplasticity:
Richard Davidson, a neuroscientist at University of Wisconsin has led experiments in collaboration of the Dalai Lama on effects of meditation on the brain. It was found that meditation can lead to different levels of activities in brain regions associated with affects such as attention, anxiety, depression, fear, anger and compassion as well as the ability of the body to heal itself. These functional changes may be caused by changes in the physical structures of the brain.
While meditating, the brain forms new neuronal connections associated with positive feelings.
People often are not aware of what they are doing as they can function by using an automatic gear. Without awareness, the mind cannot get accurate information in to help with learning and memory. Living a life without mindfulness or awareness of the present moment is similar to sleepwalking in life.
Research found that learning multiple languages restructures the brain and boosts the brain’s capacity for plasticity. The demand of handling more than one language requires more efficient connectivity within the brain.
- Reading and continue learning new skills will improve neuroplasticity.
- Exercise: aerobic exercise at least 150 min of moderate intensity or 75min of high intensity per week.
- Dancing was found in one study to be superior to repetitive physical exercise such as cycling in inducing brain plasticity in the elderly. There is a combination of physical activity with sensory, cognitive challenges, spatial orientation and integration between movements and sound. It can strengthen the connectivity between both cerebral hemispheres. MRI showed significantly larger volume in multiple frontal, temporal cortical areas such as the hippocampus. This raises the possibility to counteract the detrimental effects of aging in the brain and reducing the risk of dementia.
- Learn to play a musical instrument.
- Reduce stress: it is often difficult to reduce the sources of stress in life but we can always change how we respond to it. Going out to enjoy nature, travelling to new places will help to reduce stress.
Get enough quality sleep: chronic lack of sleep reduces neuroplasticity.