A team of researchers have found that patterns of activity in the brain associated with nitrous oxide, ketamine and LSD overlap, suggesting a common underlying biology.
Michigan Psychedelic Center researchers, George Mashour, M.D., Ph.D. and Richard Harris, Ph.D., at the University of Michigan Medical School, have conducted a study investigating the neurobiology of psychedelic experiences.
To investigate whether or not the neurobiology of the psychedelic experience was similar across substances, the team used fMRI to examine the brain activity of healthy people who were administered nitrous oxide, then compared this to data collected from participants in different studies who were given ketamine and LSD.
This data was also compared to a control group comprised of participants administered propofol, a commonly used anaesthesia drug, to distinguish between brain changes not related to the psychedelic experience.
Brain connectivity
In their paper, ‘Classical and non-classical psychedelic drugs induce common network changes in human cortex’, published in the journal NeuroImage, the team state that participants under the influence of each psychedelic drug had decreased connectivity within a particular network.
However, they also had increased connectivity across various networks.
They note that although there were differences, each psychedelic increased connectivity between the right temporoparietal junction and intraparietal sulcus in both hemispheres of the brain, and between the precuneus and left intraparietal sulcus.
These nodes are located in the so-called cortical “hot zone” of the brain, an area proposed to be critical for determining the content of conscious experience, they add, and that this could help explain the altered states of consciousness described by people administered these psychedelic substances.
The researchers suggest that the overlapping patterns of activity between the substances could point to a common underlying biology, and that additional research to determine the specifics of this biology could help researchers determine how best to use psychedelics as therapeutics.
