If chemicals like oxytocin, dopamine, and serotonin are so crucial to our mental health, why can’t we monitor them the same way diabetics monitor insulin?
In: 7327
Neurotransmitters are tiny molecules used only to send signals from one brain cell (neuron) to another one right next to it. One cell releases only a few molecules of them, they cross the tiny gap between cells, and then they are reabsorbed. They don’t just hang out in your brain between cells over long periods, and the amounts are too small to measure anyway.
But the bigger issue is that your brain doesn’t use “blood.” It’s actually completely separated from your bloodstream by a special filter called the blood-brain barrier. Your brain cells instead swim in something called cerebrospinal fluid, and the barrier only lets very specific molecules from your blood in/out of this fluid. Neurotransmitters are not one of them.
In other words, we can’t draw blood from your arm to figure out what’s going on in your brain. We would have to cut into your brain. And doing that breaks the blood-brain barrier, which is dangerous and harmful. And even then, we would have no way of reaching in between cells and measuring the tiny amounts of neurotransmitters firing between them in real time anyway.
Now, there happens to actually be some neurotransmitters in your bloodstream. Serotonin, for example, is also used as part of digestion, and can be picked up in a blood test. But this blood serotonin is not passing in/out of your brain, so is not a useful measurement for mental health, for the same reason an injection of serotonin in your arm wouldn’t help you there either.
Latest Answers