Now it has been discovered that, in addition to these psychological alterations, psychedelic drugs also alter brain cells in rats and flies, making neurons more likely to branch out and connect with each other.
David Olson, of the University of California in Davis (USA), and his team, tested three specific psychedelic drugs, LSD (also known as acid), DMT (N-DIMETHYLTRIPTAMINE) and DOI (2,5-Dimethoxy-4-iodoamphetamine ) in rats and flies. All three increased the growth of new connections in the brain, both in isolated cells and in live animals.
"People have always assumed that psychedelics are capable of altering the neuronal structure, but this is the first study that clearly and unequivocally supports that hypothesis, what is really exciting is that psychedelics seem to reflect the effects produced by ketamine." explains Olson, in a release of the aforementioned university.
Effective against depression
The work, published in the journal Cell Reports, supports the theory that psychedelics may help fight depression, anxiety, addiction and post-traumatic stress disorder.
The idea that depression comes from unbalanced brain chemistry remains popular, but recent studies have revealed that depression manifests as structural changes in brain circuits or atrophy in parts of the brain.
This does not mean that neurons die during depression, but neurites do retract. Neurites are the sections (axons or dendrites) of a neuron that project to close the gap between two neurons during the synapse (connections between neurons) to facilitate communication.
"One of the hallmarks of depression is that neurites in the prefrontal cortex, a key region of the brain that regulates emotion, mood and anxiety, tend to wilt," explains Olson. These brain changes also appear in cases of anxiety, addiction and post-traumatic stress disorder.
In his article, Olson and his colleagues tested the psychedelics of amphetamines known as tryptamine and ergoline. Both in test tubes and in experiments with animals, psychedelics showed functional and structural changes as promoted by ketamine in cortical neurons. Ketamine is a drug used in medicine for its sedative, analgesic and above all, anesthetic properties.
The psychedelics increased both the density of the dendritic spines and the density of the synapses. Some tested psychedelics, including LSD, proved to be more potent and effective than ketamine in promoting neurite growth.
The researchers did not do any human experiments, but experiments on vertebrates and invertebrates showed that psychedelics produced similar effects in all species.