Depression and the brain – neurotransmitters, a hell of a ride!

Neurotransmitters are chemicals that relay messages from neuron to neuron. An antidepressant medication tends to increase the concentration of these substances in the spaces between neurons (the synapses). In many cases, this shift appears to give the system enough of a nudge so that the brain can do its job better [1]. Sounds weird? I’ll explain it in this post the best I can.

In my previous post I looked closer at the parts of the brain involved with the regulation of mood. Today we’re going to take a close look at a level in the brain that is so genius, you won’t believe it. As you are reading this, your brain is working! We’ll have a look at the cells and how they communicate.

 

 

Neurotransmitters and the brain, how does it work?

While every little cell in the body has the capacity to send and receive signals, neurons (special cells) are made for this. A neuron has an ‘antenna’ (the axon and the axon terminal) to send the signal to another one. It is a very clever system. They send chemical and electrical signals and in that way neurons can communicate. I imagine a string of Christmas lights that are being lit one for one. The lights itself are the neurons, the string are the axons and the axon terminals and then there is the magic!

The signal travels from the cell body through the axon to the axon terminal where chemical messengers (the neurotransmitters) are stored. The magic happens here, the signal releases certain neurotransmitters into the space (the synapse) between that neuron and the axon dendrite of the neighboring neuron. Also of  importance is the concentration of the neurotransmitters in the synapse. You can imagine that a lesser quantity doesn’t send a powerful message in comparison to a synapse that is ‘filled’ with neurotransmitters.

One neuron communicates with the next one through neurotransmitters. The message that is send can be activating or inhibit the next neuron. The message will be passed further along or being suppressed. The body takes care of itself, once an amount of neurotransmitters are released, a feedback mechanism tells that neuron to stop and bring it back into the cell (this is reuptake or reabsorption). I imagine it like a wave on the beach, the wave comes up but retraces at a certain point. What stays behind is being cleaned up by enzymes, they break down the molecules into smaller particles.

 

CNX_Chem_03_01_exocytosis

 

What happens when it doesn’t work as planned?

That is how the system works, it is perfect but sometimes something doesn’t go as planned. Sometimes the receptor of the next neuron can be oversensitive or insensitive to the neurotransmitters that are coming their way. They don’t respond as good, the door is way to open or closed. That poses a problem for the communication between cells. Sometimes they are too much neurotransmitters or the enzymes clean way to thoroughly. All those scenarios will have an effect on the mood regulation.

 

 

What kind of neurotransmitters are involved with depression?

Are you still with me? I just adore those things! When you thought with the Christmas lights in your head that that is all, you’re wrong. We have many different kinds of neurotransmitters. Different chemicals that are being passed on from cell to cell. A few are being linked to depression. They have fancy names, if you can use them in a game of scrabble, you’ll win the game, guaranteed!

  1. Acetylcholine. Enhances memory, involved with learning and recall.
  2. Serotonin. Regulates sleep, appetite, mood and regulates pain. Seems like it regulates quite a bit when you think about some symptoms of depression no? Low levels of serotonin byproduct are linked to a higher risk for suicide.
  3. Norepinephrine. Constricts blood vessels, raising blood pressure. It may trigger anxiety and be involved in some types of depression. It also seems to help determine motivation and reward.
  4. Dopamine. Is essential to movement. It also influences motivation and plays a role in how a person perceives reality. Problems in dopamine transmission have been associated with psychosis. It’s also involved in the brain’s reward system, so it is thought to play a role in substance abuse.
  5. Gamma-aminobutyric acid (GABA). An amino acid that researchers believe acts as an inhibitory neurotransmitter. It is thought to help quell anxiety.

 

 

To recap this post:

An electrical signal travels down the axon → Chemical neurotransmitter molecules are released → The neurotransmitter molecules bind to receptor sites → The signal is picked up by the second neuron and is either passed along or halted → The signal is also picked up by the first neuron, causing reuptake, the process by which the cell that released the neurotransmitter takes back some of the remaining molecules.

 

 

Isn’t it wonderful what we already know about the brain? Medicine has come a long way. What we can’t do is open our brains and go ‘shopping’ for a better neurotransmitter. As you understand the system isn’t that clear cut as ‘too much’ and ‘adjust a bit’ and you’re ready to go! The onset of depression is the result of many things. Your doctor or mental health professional can help you to make a plan of action. There are different areas that play into depression and today we covered neurotransmitters. Next week we’ll discover yet another area. You as a person are the sum of all these areas, you have your own thoughts, history, genes and so on. All these levels make you unique and wonderful. It also makes it difficult to unravel what exactly is going on while dealing with mental illness. It is a journey and I hope you’re on board!

 

 

References.

 

[1] Online source. Health Harvard. Mind and body, what causes depression? (2019). Full article, click here.

Picture 1 credits Background vector created by GarryKillian – www.freepik.com

Picture 2 credits click here.

17 thoughts on “Depression and the brain – neurotransmitters, a hell of a ride!

      1. I will re-read and hopefully some more will sink in. It’s new territory for me – It’s very impressive that you know all this stuff. Tell me, is this coming from your degree, or do you know it from your own experience? Computers are easy though compared to this stuff. Only tonight I succeeded in controlling some christmas lights with my voice. Big wows 😀

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      2. The knowledge comes from my education, the interest comes from me and the fact that I found an ‘audience’ in the bloggingworld comes from lack of interestest from my former workplace in those things. And the time to write and to do research comes from my depression 🙂 I just really like these things 🙂 Controlling christmas lights by voice, impressive! Maybe if I ask mine politely they’ll come out of the box 😀

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  1. I can come up with some sensible questions (ok, I shall let you be the judge!), however. If antidepressants tend to increase neurotransmitters, is there considered to be an “optimal” level? And, can neurotransmitters, therefore, be measured? That almost suggests that you could place someone on a scale somewhere. It has got to b more complicated than that, surely?
    Sorry, I am used to thinking in terms of numbers, not in terms of human beings! Numbers are far easier.

    Liked by 1 person

    1. The body likes everything balanced, like nature. So optimal would be when the neurotransmitters are more or likely balanced. That will help the person to build up more resilience and possibilities to take on past and present issues. Neurotransmitters cannot be measured in the brain. Normally psychiatrist increase or decrease medication on the effects that the patient reports. The whole thing is also influenced by hormones and genes for example and will differ from person to person so there are no ‘optimal’ levels to obtain other that ‘feeling better one day at a time’. Next week I’ll discuss the gene theme 🙂

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  2. It’s Tuesday! Only took me 10 hours to finally get a minute to catch up on my reading. So, maybe you can’t answer this and I’m sure if I just Googled it, I could learn, but I’ve always heard this “electrical signal” stuff. I know how electricity works in like a light bulb, but I don’t understand it in terms of brain science. It can’t be the same kind of electricity, can it? Does electrical mean something else? Is it just the act of transmitting anything? Don’t worry if you can’t answer it.

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    1. I don’t remember how that is but I would think that is could be the same principle, a way of transmitting energy. Dr Google would know better but I believe that neurons have a positive ‘side’ and then they ‘go’ and a negative side when they retract. That is how cells are able to communicate. The real mystery would be how we ‘charge’ them, the fuel would have to be the breath I would think. Maybe that is also the reason why they sometimes use electrical shocks on the brain, does that makes sense?

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    1. Thank you so much, I’m glad christmas lights and waves made it more approachable. I’m a champion in visualisation and I find using metaphores helps me to ‘grasp’ things better.

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