Have you ever wondered why some people seem to react more to the world than others?
Some physiology for those who like to know why and how
…and a TL;DR at the end for those who don’t.
Messages travel along nerves by setting off a shift of charged ions (K+, Na+) which move between the inside and the outside of the nerve cell through ion channels or gates. The gates open and close in response to the relative change in the overall charge in that region of the cell. The progression of the message along the nerve cell is referred to as an action potential (AP).
An AP in any one nerve cell is triggered at the synapse between the nerve cells. Below is a stylized diagram of a synapse between two nerve cells. In reality, there is a massive web of connections between billions of nerve cells throughout the central nervous system (CNS ~ spine and brain). One nerve can be involved in many synapses and in this way can amplify the strength of the message travelling within the system.
(1)
Another way that a message can be amplified is through the action of glial cells, such as astrocytes, in the CNS. Glial cells were once thought to be only a structural matrix for the nerve cells. However, we now know that the glial cells play a much bigger role. They refine the connections between the nerve cells in the CNS. They are constantly reinforcing the neural pathways or downgrading them and editing them out (read more here). This affects learning, memory and every action/reaction/response you have to the world around you (both within your body and externally).
(2)
Astrocytes stick their “fingers” or dendrites into every synapse. Their influence increases the strength of a message (travelling via that nerve) by stimulating the receiving nerve to have a greater number of ion channels in its synapse. More ion channels means the nerve is more quickly stimulated to produce an AP and is “heard more loudly” in the brain. In doing that, this pathway of thought/action/reaction becomes more significant and contributes in a bigger way to our perceptions of, and responses to, the world around us (internal and external).
Deep Breath.
So why am I dragging you through this histology and molecular biology? How is this relevant to you? How is this important to your daily living? I’m glad you asked. It turns out that your Mum was right!
We are born with a pattern of neurology. Throughout life it responds and adapts to the things we are exposed to ~ thoughts, movements, chemicals. As we experience life, our neurology is tailored by our glial cells (e.g. astrocytes; neural pathways, thought patterns and memories are consolidated or deleted. These changes in our CNS then impact on how we respond to experiences down the track. Another name you may have heard for this is neuroplasticity (read more here).
It turns out that certain stimuli (thoughts, movements, chemicals) can prime our nervous system to be hypernociceptive (more likely to perceive pain). These things include (but are not limited to): stress, alcohol, drugs, poor sleep, upbringing (early childhood stress while the CNS is developing), diesel exposure, and a non-diverse microbiome (see box). All of these triggers create a pro-inflammatory hypernociceptive state as the starting point for a person’s nervous system. This person might then stub their toe and experience a debilitating pain and disfunction for a fortnight; as opposed to another person without a pro-inflammatory hypernociceptive state who had the same stubbed toe incident and shrugged it off as inconsequential. This is why people can have similar accidents/diseases yet experience very different responses or recoveries.
So, if stress, drugs, alcohol, and low sleep etc. promote changes in the CNS synapses to create a hypernociceptive state, are we stuck with it?
Neuroplasticity means the CNS is adaptable in BOTH directions. Astrocytes can be encouraged to reprioritise neural pathways in the CNS such that a person can recover from a hypernociceptive state. And here’s the thing I love about this ~ science has confirmed the things we’ve known forever (but that used to be written off as just Mum’s nagging). We know what’s good for us, we just have to DO IT!
To recover from a hypernociceptive state we need to:
Thus, if we sleep, exercise, think and eat well consistently, our CNS will be remodelled by our glial cells and recovery from a hypernociceptive state is possible.
Mark Hutchinson describes this as ~
I call it a collection of good lifestyle choices that create a cellular change in our brain making a HUGE positive difference to our health and wellbeing.
The most exciting thing about this is that these are all things that we can do easily. Each person has the power to make these changes themselves: the power to use neuroplasticity as a force for wellness, not disease and dysfunction. Go for it!
TL;DR ~
Science has now established the mechanism by which making good lifestyle choices changes the cellular structure of the nerves in your brain and promotes a healthier, happier and more able body.
So when your Mum says, “Get more sleep/do some exercise/look after your headspace/choose better eating options”. She’s right! Just do it!