A classic psychedelic similar to LSD, psilocybin and mescaline has been found to activate a type of cell in the brain that silences other neighboring neurons, a result that provides insight into how these drugs reduce anxiety, according to a new study.
The findings show that the psychedelic DOI (2,5-dimethoxy-4-iodoamphetamine) reduced anxiety in mice and rats while activating the ventral hippocampus and so-called fast-firing interneurons there.
“It was not known which brain areas and cell types are involved when psychedelics suppress anxiety,” said Alex Kwan, an associate professor of biomedical engineering at Cornell University and senior author of the study, which was published today in the journal Neuron“The idea is that if we know the neurobiology involved, we can design better drugs that target these pathways.”
“The work provides insight into the cellular trigger of psychedelic-induced anxiety relief,” said Vidita Vaidya, a senior professor of biological sciences at the Tata Institute of Fundamental Research in Mumbai and corresponding author on the paper.
The pathway in the ventral hippocampus (a brain structure involved in social memory, emotion and affect) does not appear to cause the hallucinations that are a hallmark of DOI, suggesting that some of the therapeutic effects of psychedelics (including reduction of PTSD, depression and anxiety) may be isolated within discrete brain circuits, Vaidya said.
“This opens up the possibility of designing psychedelic-inspired drugs that attack anxiety without causing powerful hallucinations,” he added.
The study builds on previous research that identified abnormal hyperactivity in the ventral hippocampus when an animal is anxious, particularly in neurons that communicate with the amygdala, the main emotion processing center.
“There is a hint that in the anxiety state, these cells are active and perhaps the drug works by silencing some of them,” Kwan said.