Written by Catherine Mullins
What is Neuroplasticity?
Neuroplasticity is the lifelong ability of the brain to undergo structural and functional changes in response to experiences. The medical world once thought that the brain stops developing in childhood but we now know that ongoing changes occur right up until death.
Information in the brain is transmitted from neuron to neuron via synapses (spaces). This is done through action potentials sending electrical signals along the neurons causing neurotransmitters (chemicals) to be released across synapses, attaching to the next neuron and continuing the process. Each synapse (space) can be linked to multiple neurons, therefore receiving information from a variety of sources. Neuroplasticity looks at the changes that can be made between neurons and synapses.
How does it change
Change can occur through the strengthening of existing connections, elimination of existing connections, or forming of completely new connections. Neuroplasticity is a huge component of rehabilitation following damage from strokes etc but it also very useful in recovering from acute injuries (eg changing balance and reaction times) or from chronic pain (changing movement strategies and functional capacity).
Not all neuroplastic changes are beneficial. Sensitisation of the nervous system can occur with strong or continuous stimulation, release of chemical mediators or by activation of the neuroimmune system. This can negatively impact the firing of neurons by decreasing the amount of input needed to fire (reduced threshold) or increasing the reaction to a normal level of input (increased responsiveness). This means that things will start to cause a response at a much lower level of input, or with an exaggerated response. I often use the analogy of a fire alarm. We need a fire alarm to alert us when there is smoke and fire for our safety (i.e. a cut on the hand from a knife) but when the alarm goes off with burnt toast (i.e. a pen across the back of the hand) or even with steam from the kettle (a feather or clothing on the back of the hand), this is less useful and less accurate for us.
What causes changes
It’s not just physical input that can create change. Most people have heard of stress releasing cortisol into the body which is beneficial for the fight or flight responses but over time excess cortisol in the brain can prevent neuroplastic changes from occurring. Lifestyle factors such as poor sleep/nutrition or under or over exercising can lead to systemic inflammation in the body, increasing chemical mediators that further sensitise the nervous system.
Deliberate engagement creates stronger connections. In the words of Donald Hebb, “neurons that fire together, wire together”. The more that you follow a pathway, the stronger that pathway becomes. It’s all about deliberately choosing the pathway you want to follow!
Look out for Catherine’s next blog on Neuroplasticity in Chronic Pain