Low Doses of Psychedelic Drug Eased Fear in Mouse Models
Psychedelic drugs can severely alter one's cognition and perception, especially when taken in high dosages. Since these drugs can cause hallucinations with potentially dangerous side effects, psychedelic drugs are usually illegal in most places throughout the world. Despite the legality of these drugs, a new study found that when a psychedelic drug was given in really small dosages to mouse models, it proved to be effective in treating conditioned fear.
In this study conducted by a research team from the University of South Florida, the researchers set out to evaluate the effects of psilocybin on memory formation and learning in the brain. The compound is known to stimulate serotonin receptors, improve mood and alter perception and thinking in the brain, and was previously believed to be a hallucinogen. However, due to newer research, psilocybin does not seem to influence seeing or hearing when taken in low to moderate dosages. Now, researchers are interested in studying how psilocybin could potentially be used medically.
For this study, the researchers classically condition fear into their mouse models. The process involved using an auditory tone that was followed by a small pause before a shock, similar to static electricity was administered to the mice. Once the mice were conditioned, they would freeze once they heard the auditory tone. The researchers then reversed the condition by playing the tone later on in the experiment without the shock. During the experiment, the researchers were administering low doses of psilocybin and a serotonin inhibitor, ketanserin.
The researchers found that the two types of compounds given to the mice did not affect how fast the mice learned the fear response. The researchers did find that mice that were given psilocybin were quicker to recover from the conditioned fear response. The researchers also found that mice given the low doses had an increased growth of neurons located in the hippocampus.
"Psilocybin enhanced forgetting of the unpleasant memory associated with the tone," Dr. Juan Sanchez-Ramos, MD, Ph.D. said according to Medical Xpress. Sanchez-Ramon is a neurology professor and the Helen Ellis Endowed Chair for Parkinson's Disease Research at the USF Health Morsani College of Medicine. "The mice more quickly dissociated the shock from the stimulus that triggered the fear response and resumed their normal behavior."
The researchers hope that these findings suggest that psilocybin could possibly help treat people with posttraumatic stress disorder (PTSD). The study was published in Experimental Brain Research.