I keep reading all these recreational drugs increase dopamine – the ‘feel good’ drug in the brain. So why is just injecting dopamine itself not a thing?
In: Biology
One thing to add to these explanations is that Dopamine is often injected intravenously for a different purpose. It causes a rise in blood pressure and stimulates the heart (frequently used in cardiac surgery for example).
Serotonine is over here just thinking ‘well, fuck my drag, right?’ – the truth is that dopamine is one part of the process there are a series of differing ways in which different aspects of brain chemistry are affected by recreational drugs. It really depends what you are talking about by recreational drugs as well: ketamine has a different affect to cocaine has a different affect to MDMA has a different affect to psychedelics.
As many people have already said , dopamine is not just a ‘feel good’ hormone, it can’t cross the blood brain barrier and would have to be directly injected into the brain, and it would fudge around with a whole host of other processes in the body.
One reason why many people don’t use recreational drugs frequently, i.e., only for special occasions, festivals etc., is that often the ‘euphoria’ that is felt during drug use is the result of brain chemistry being pushed out of its comfort zone – this comes with consequences – fatigue, tiredness, depression, emotional detachment, etc.. When used infrequently and recreationally, these after-effects are less severe and last for/occur a few days after use but more frequent and combined use of recreational drugs can have more severe, longer lasting effects. (it’s difficult to state clearly how so with each drug, due to the limitations with testing on humans, and even obtaining the chemicals legally and professional for clinical study)
Unfortunately it’s not so simple as messing with one variable because the brain is not just a simple input-output mechanism. It’s very tough for even the most experienced mental health professionals to prescribe the correct drugs at the correct dosage for patients because they are trying to ‘correct a brain chemistry imbalance’ and get the desired effects – but without pushing anything too far or interfering with other processes.
I mean this is even the same with something like nutrition, we are coming to understand the different ways that the body is designed to breakdown, extract and absorb different chemicals through the digestive system … many foods contain calcium for example…. but then you have to consider in what form, in what molecules – can the body break them down efficiently, how efficiently will it be able to absorb it in that form, what other chemicals are in that food – do they interfere with that breakdown and absorption process (either positively or negatively)? It’s rarely as simple as simply putting more of one thing into the body to achieve the desired reaction – you always have to consider the different mechanisms the thing you are imputing will interact with in the body and if it will actually be a net gain.
Injecting dopamine will not work as dopamine will not cross the blood-brain-barrier. L-Dopa which is a precursor of dopamine is injected into the body as it can cross the blood-brain-barrier and is converted to dopamine in the brain. This is commonly used in managing Parkinson’s symptoms.
I don’t know the first thing about any of this but if it was purely the dopamine itself that made you feel good then all drugs would produce the same high I’m sure that it’s a mixture of (insert drug of choice here) along with dopamine from the action of doing said drug = good feeling
We infuse dopamine into people quite regularly to treat hypotension (dopamine is an inoconstrictor). Maybe for the reasons people have mentioned or maybe because they’re usually dying of sepsis, the patients tend not to report feelings of elation.
When your neurons talk to each other, they send chemicals to each other. Dopamine is one such chemical. It’s all about keeping a good balance. Imagine every time they talk, they send three letters. Drugs are used to send more or fewer letters. But adding just one additional or one less is enough to fix things. Injecting the brain with dopamine is like dropping a whole bag full of letters everywhere. That’s gonna cause confusion and information is going to stop flowing properly. It would change things too much.
First of all, dopamine is not a feel good drug.
Dopamine is a neurotransmitter in the brain involved in several function.
1 : It’s involved in motricity, when your get Parkinson disease, your dopaminergic neuron dies and this causes the motor symptoms.
2 : It’s involved in vision : Some neuron in the retina layers respond/secret dopamine.
3 : It’s involved in hormonal control of like prolactine in the tubero-infundibulum pathway (around the hypophyse)
4 : It’s involved in MOTIVATION in the reward/limbic system. MOTIVATION, not pleasure.
The point of dopamine is to associate a pleasing sensation with an action so you can feel motivated to do it again. It’s at the core of what we call “the reward system” and it motivates you to do stuff.
When you’re eating food, it feels good, what feels good is associated with being beneficial to your survival so you have all the interest in the world to repeat that action so you can thrive.
Dopamine acts like a glue between the “feel good feeling” of eating and the action of eating, so you can associate the two together and later on get more motivated to do it.
Drugs hijack this system by inducing a massive dopamine release while the drugs provoke a feel good sensation : The massive dopamine release associate the feel good feeling with the drugs and you start getting more and more motivated to do it again : That’s how addiction begin.
But dopamine is not pleasure. They did an experiment on rats if you remove the dopaminergic neurons in a region called “the ventral tegmental area” which is the core of the reward system, rats will still exxperience pleasure when they drink sweet water (because rats really like sweets) but they will let themselves die of starvation because they will feel absolutely no motivation to reach for food.
And in drug addiction, way before physical withdrawal kicks in, you get an obsessive motivation to get drugs : that’s called craving. It’s not a seeking of pleasure, it’s a seeking to relief a compulsion : You NEED to do it, you are pushed to do it, you cannot do otherwise. But the pleasure is long gone.
Also, dopamine does not cross the blood brain barrier. So dopamine injection wouldn’t work.
Dopamine is known as being a happiness hormone, but other than the brain it also plays a part in the immune system, kidneys and digestion. As others have said getting it into the blood stream won’t alter your mood in addition due to the other roles of dopamine it isn’t just a neurotransmitter there is a bit more going on and you don’t really want to tamper with it. https://youtu.be/LRGfGoRXqQY
Because the dopamine is being released in the synapses of the brain. It doesn’t just flow directly there from the blood stream, and dopamine in the blood would not have the desired effect. There are actually situations where a dopamine injection is a good idea, but that’s like, heart failure, not wanting to get high.
Dopamine cannot cross the blood/brain barrier. Injecting it into your bloodstream wouldn’t work. Injecting it directly into your brain would create all sorts of other problems. Starting with the fact that you just stuck a NEEDLE into your BRAIN.
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