Researchers have found that psychedelic substances such as LSD (lysergic acid diethylamide), DOM (2,5-dimethoxy-4-methylamphetamine) and DMT (dimethyltryptamine) induce an increase in the number and activity of connections between cells (synapses).
“People have long assumed that psychedelic substances are capable of altering neural structure, but our study is the first to clearly and unambiguously support this hypothesis,” says David Olson, leader of the Californian team who published its findings in Cell Reports.
Several studies have indeed shown the effectiveness of hallucinogenic compounds used for therapeutic purposes, in particular to treat anxiety and depression. However, the mechanism of action of these drugs on the brain was unknown and, given their dangerousness, they were rarely used clinically. The hypothesis formulated by the American team is that, like other antidepressants, such as ketamine, they could increase the activity of the prefrontal cerebral cortex, compromised in depressed subjects.
The researchers conducted experiments on neuronal cells cultured in the laboratory and on the brains of different animals: fruit flies, zebrafish and mice. After drug administration, they observed changes in the structure and activity of neurons. Result: DMT, LSD and DOM increase the dendritic ramifications – neuron prolongations that allow nerve communication – in the brain of invertebrates (fruit fly) and vertebrates (mice). The dendrites also acquire more protuberances (dendritic spines). Changes in cellular morphology also result in increased activity of the cerebral cortex.
According to the researchers, the really promising result is that psychedelics seem to mimic the effects of ketamine, a hallucinogenic molecule used to treat depression. “Ketamine is no longer the only option, and our work shows that there are a number of separate chemical molecules capable of promoting plasticity like ketamine. They provide chemists with additional opportunities to develop safer and more effective alternatives,” said Olson. And it is towards this direction that the research team is currently heading: the identification of new antidepressant drugs, safe and non-addictive, based on the structure of psychedelic compounds.