Is there a common path to the psychedelic experience? — Daily Science

Nitrous oxide, colloquially known as laughing gas, has been used clinically as an anesthetic to relieve pain since the 19th century.^he century. However, in smaller amounts, it can induce mind-altering experiences, including feelings of happiness, spirituality, and out-of-body sensations, much like those induced by the psychedelics LSD and ketamine.

A study led by George Mashour, MD, Ph.D. and Richard Harris, Ph.D., of the recently founded Michigan Psychedelic Center at the University of Michigan Medical School, take a closer look at the neurobiology of psychedelic experiences.

Using fMRI, the team examined the brain activity of healthy people given nitrous oxide and compared that activity with data collected from participants in different studies given ketamine and LSD to see if the neurobiology of psychedelic experience was similar.

Additionally, these data were compared to a control group consisting of participants who were administered propofol, a commonly used anesthetic drug, to distinguish between brain changes unrelated to the psychedelic experience.

The team noted that participants under the influence of each psychedelic drug had decreased connectivity within a particular network, but increased connectivity across multiple networks. Although there were notable differences, each psychedelic increased connectivity between the right temporoparietal junction and the intraparietal sulcus in both brain hemispheres and between the precuneus and the left intraparietal sulcus.

These nodes, they point out, are located in the so-called cortical “hot spot” of the brain, an area proposed as critical for determining the content of conscious experience. This could help explain the altered states of consciousness described by people who were administered these psychedelics.

The fact that the activity patterns associated with nitrous oxide, ketamine and LSD overlap suggests a common underlying biology, they add. Additional research to determine the details of this biology could help researchers determine the best way to use psychedelics as therapy.