What are the basics of brain chemistry

Question to the brain

Answer by Frank Faltraco, Senior Consultant in the Clinic and Polyclinic for Psychiatry and Psychotherapy at the Rostock University Medical Center: The short answer to this question is - at least so far - no! This is not yet possible in the clinic. It is true that the concentration of neurotransmitters can be measured in animal experiments with electrical or chemical probes directly in the brain, but unfortunately the animals usually do not survive that.

At least the density of transporter molecules and receptor molecules that interact with neurotransmitters such as dopamine can be determined less invasively. This works with imaging methods, positron emission tomography (PET) or single photon emission computed tomography (SPECT), in which weakly radioactively labeled substances are administered that attach to the same molecules as the neurotransmitter. The spatial and temporal distribution of these substances can be made visible in the imaging and can even provide indirect information about where neurotransmitters interact with the transporters and receptors. But this is not the same as a direct measurement of neurotransmitters in the brain!

For the future, however, it is conceivable that such procedures could also be used to diagnose disorders of thought and concentration. There are already initial studies on this, for example investigating the neurotransmitter norepinephrine in ADHD. Work is also underway on the development of minimally invasive electrochemical probes that can be inserted into the human brain to measure neurotransmitters in the field, but this is still a long way from clinical application.

Internet offers that advertise that “brain chemistry” can be measured directly with the help of blood and urine samples are mostly not scientifically validated enough. If you read carefully, the precursors or breakdown products of neurotransmitters in the body are measured and not the concentration of the messenger substances itself in the brain. There is at most an indirect connection.

It should also be remembered that neurotransmitter concentration is only one facet of mental and neurological illnesses. For example, we know from animal experiments that the concentration of neurotransmitters in the brain increases rapidly after the administration of drugs against depression. However, it takes several weeks for a positive effect on the mind to set in, so other mechanisms must also play a role. The function of complex cascades is more important than just the neurotransmitter concentration.

For a serious clinical diagnosis of thinking and concentration disorders, the classic methods remain for the time being. We use psychological questionnaires, sometimes brain imaging, and rule out organic causes that could also be responsible for the symptoms observed. Only when something is left can one arrive at the diagnosis of a mental disorder.

Recorded by Nora Schulz