Researchers at Johns Hopkins Medicine have discovered that psychedelic drugs can “reopen” critical periods of the brain, timeframes when mammals are more receptive to environmental cues that influence brain development. These critical periods, usually open during early developmental stages, play a vital role in learning new languages, regaining motor skills post-stroke, and establishing visual dominance in one eye over the other.

In this study, the researchers examined the effects of five psychedelic drugs – ibogaine, ketamine, LSD, MDMA, and psilocybin – on the social learning of adult male mice. The drugs varied in their duration of impact, ranging from 48 hours with ketamine to a staggering four weeks with ibogaine.

Notably, psilocybin – the active compound in magic mushrooms – reopened this ‘critical period’ of enhanced learning for two weeks with a single dose. This provides a new perspective on how these drugs work, hinting at their potential for treating a broader range of conditions beyond their current uses, such as depression, addiction, and post-traumatic stress disorder.

The researchers also found that the reopening of these critical periods correlates with the duration of the psychedelic drug’s acute effects as reported by people. This could help understand why each drug may have longer or shorter effects on opening the critical period.

Additionally, an examination of molecular mechanisms revealed significant differences among the drugs. LSD and psilocybin, for instance, utilize a serotonin receptor to open the critical period, while MDMA, ibogaine, and ketamine do not. Furthermore, gene expression differences were observed, particularly among genes that regulate proteins involved in maintaining the brain’s extracellular matrix, crucial for social learning behaviors.

This pioneering research opens new pathways in understanding the therapeutic applications of psychedelic drugs, although it’s essential to remember that these findings are primarily based on studies in mice, and human results might vary.

This study was conducted by a team led by Gül Dölen, M.D., Ph.D., associate professor of neuroscience at the Johns Hopkins University School of Medicine. The research was funded by various institutions, including the National Institutes of Health.