An international team of neuroscientists, anesthesiologists and other medical researchers has learned more about the changes that occur in brain neurotransmitter systems under the influence of psychedelics, anesthetics and cognitive enhancers by studying PET and fMRI scans of brains of people administered such drugs. The study is published in Science Advances.

Prior research has led to the use of a variety of mind-altering drugs by medical practitioners in medical contexts to achieve beneficial medical results—anesthetics allow for conducting pain-free surgery, for example, and psychedelics have proven to be useful tools for treating mental disorders such as PTSD. What is not known, however, is the additional impact such drugs have on the brain. In this new effort, the researchers sought to learn more about the effects on a neural system level.

The researchers obtained and analyzed 1,200 PET scans of human brains under the influence of mind-altering drugs, either as part of medical treatment or as part of work in other research efforts. The scans were divided by category; psychedelics, anesthetics and cognitive enhancers. They also analyzed a second dataset of fMRI brain scans taken after administration of mind-altering drugs.

The research team found that the drugs had impacts on multiple neurotransmitter systems—not just those being targeted. In addition to expected relationships, such as links between MDMA and serotonin receptors, they found that many of the mind-altering drugs could impact neurotransmitters distant from intended targets. They also found that such unintended consequences could differ depending on the dosage of the drug administered.

The researchers suggest their work provides a new starting point for studying the far-reaching impact of mind-altering drugs on patients, and also for learning more about how neurotransmitter systems are related. They also suggest that what they learned in their work could be useful in vetting new drugs.

--Bob Yirka, Medical Xpress