Serotonin. The Multifaceted Chemical.

Serotonin. It is one of your brain’s important neurotransmitters. One you have probably heard of before. It is most commonly talked about in the context of mood disorders such as depression where drugs like Prozac act as “selective serotonin reuptake inhibitors”.

But serotonin’s story is about so much more than just depression. It is also one which is shrouded in much over-hype and false neurobabble.

Back to Basics. 

Let’s for a moment imagine that we are able to look inside the human brain with a very powerful magnifying glass. If you zoomed in on a serotonin cell – i.e. a cell which releases the chemical serotonin – you might be quite surprised. Because a single cell can extend up from your brain stem, the base of your brain, all the way into the deepest reaches of your brain.

That is because all serotonin cells have their cell body (the control centre) located within specific hubs – collections of cells – forming anatomically distinct brain regions such as your raphe nucleus. But although their cells bodies are located here, their axons – the tendrils which are sent out from the cell body – together form a diffuse network throughout the brain to connect onto other brain cells.

And it is at these connections – these gaps – (called synapses in technical speak) between one brain cell and another where the tiny, but powerful, molecules of serotonin are released into the synaptic space between the cells, and then taken up by specific bits of protein machinery (called receptors) located on the surface of a receiving cell.

Chemical transmitters are needed because in most instances electrical signals – which form the brain’s long range and short range messaging system – cannot cross these gaps.

But more importantly, they provide an opportunity for regulating the level and type of activity in your brain. A point where your ongoing brain signals can be tweaked and adjusted. Strengthened or weakened as required.

What does serotonin actually “do”? 

Although it is true to say that serotonin is involved in altering your mood and is implicated in disorders such as depression, this doesn’t mean that serotonin is the brain’s “happy chemical”. In fact, there are other chemicals which some researchers believe do a much better job at making you happy.

Instead, serotonin seems to be more involved in regulating your emotions – keeping your mood in balance. And when you don’t have enough of it then that is when you can, in some instances, start to slip into a state of depression.

But if you look at the list of functions assigned to serotonin it looks a bit like this: mood, sleep and wakefulness, cognition, sexual behaviour, appetite, aggression and dominance, impulsivity, neurodevelopment, circadian rhythms, body temperature, and neuroendocrine function.

How it is that one chemical does so much?

One chemical, many functions.

Because serotonin acts in many places in the brain, and the body. The “receptors” where serotonin acts are dotted all around your brain and internal organs. And depending on what that region or organ does, then the serotonin acts to adjust, to modify, to regulate that process. It helps you to remember, it helps to put you into REM sleep, it helps you to exert you social dominance.  Without serotonin, each of these processes wouldn’t be able to happen properly.

One chemical, so many receptors. 

But there is another aspect of serotonin which shows what a multifaceted chemical it is. And this is the finding that serotonin doesn’t just work through one single type of “serotonin receptor” located on that receiving cell.

There are in fact at least 7 different families of serotonin receptors – and multiple subtypes within these families. What’s more, the particular selection of receptors that each of us carries is determined by our genes and each one of us can have a slightly different pattern of serotonin receptors in our brain.

Because each of these receptors works slightly differently – in other words, they tweak the ongoing brain signals in different ways – they can each adjust our brain responses differently.

This is one of many contributing factors which underpins what makes us all different, unique in our behaviour, our approach, and our thinking. Yes, we are all wired slightly differently. But also our neurochemistry is also different.

Can you intentionally increase your serotonin levels? 

There are factors which are known to increase serotonin levels in the brain – including exercise, bright light and sleep. However, the most controversial one is definitely diet.

For example, there are studies out there which suggest that by eating various foods like soya beans, nuts and bananas you can increase levels of tryptophan – the amino acid necessary to synthesize serotonin. In contrast, other studies suggest that the amount of tryptophan allowed to enter the brain is tightly controlled by a structure called the blood-brain barrier – your brain’s gateway.

An unbalanced diet.

Because of this, researchers such as Simon Young from McGill University believe that you have to have a significant imbalance in your intake of amino acids (something that you can do artificially if you get people to ingest a drink containing a particular mix of amino acids which is extra heavy on tryptophan) to get “extra” tryptophan across.

However, this is something that doesn’t usually happen in the course of eating a normal balanced diet – something that is necessary for keeping the rest of your body and brain in balance!

If you want to know more about the way your brain’s neurochemistry influences how you think, feel and behave then please get in touch with us at Synaptic Potential

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