American scientists have discovered that when taking psilocybin changes the activity of the fence is a small bilateral plate of the gray matter adjacent to the inner layers of the cerebral cortex. Along with this also observed in the change of its functional relationships with other areas: the auditory cortex, a network of passive mode of operation of the brain and the areas responsible for cognitive function. The fence of the brain, therefore, may be a “command center” of the influence of psilocybin on the brain and its therapeutic effect, write the scientists in NeuroImage.
In recent years, scientists pay a lot of attention to the study of psilocybin (the active component of hallucinogenic mushrooms) as a possible treatment of affective disorders: in 2016, scientists showedthat psychedelics helps with severe depression, and in 2018 the therapy psilocybine received from the FDA the status of “breakthrough”. How psilocybin affects the brain head, however, is still not well understood. It is precisely known, for example, that at the level of neurotransmitters it acts on serotonin receptors (mainly 5-HT2A), but with respect to the activity of the brain and its functional connections not so obvious, although studies showthat taking psilocybin alters the activity of anterior cingulate and prefrontal cortex in patients with depression.
Frederick Barrett (Barrett Frederick) from the Medical school of Johns Hopkins University suggested that this change in activity is some kind of command center — the area that psilocybin affects is primary, and through it already — on everything else. To test this, they conducted an fMRI experiment involving 15 volunteers: they have already taken the psychedelic drug in the previous similar study. In addition, the authors noted that all participants had many years of meditation practice — and said that none of the participants, judging by their words, during the experiment was not meditating.
Scanning took place in two stages: during the first, participants took psilocybin (in the dose of 10 milligrams per 70 kilograms of body weight), and in the second — a placebo. All the drugs that participants took in the same conditions with a blindfold and headphones while lying on a gurney — and then (after an hour and forty minutes) they were taken to the MRI scanner: the brain activity measured at rest. Six hours after taking the drug or placebo, participants also filled out questionnaires about their mental state.
Scientists noticed that when taking psilocybin compared with a placebo, participants there was a significant (p < 0.05) decrease in the amplitude of low frequency oscillations of the fence (or claustrum) is a small bilateral plate of the gray matter adjacent to the inner layers of the cortex and the connected neural pathways from different areas. When you receive psilocybin compared to placebo was also observed attenuated functional connectivity of the right fence with the auditory cortex (p < 0.001) and a network of passive mode of operation of the brain (p < 0.0001) and increased communication with the responsible for cognitive control in fronto-temporal lobes (p < 0.001). The functional relationship between the left fence and the fronto-temporal lobes when taking psilocybin, in turn, was increased (p < 0.0001). As for the polls, it is when taking psilocybin compared with a placebo, participants reported elevated feeling of happiness, loss of sense of time and other mental effects, which observe when taking any psychedelics.
The authors explained that the observed changes in the brain were specific for the fence: the detected changes in the functional relationships have not found in the performance assessment, for example, the Insula lobe and the shell. Apparently, the fence — key structure for the action of psilocybin on the brain, and its regulation of other structures can be attributed to the therapeutic effect. However, one should not forget the limitations of the sample: all participants were older than 50 years and had many years of meditation experience that has not yet been possible to reliably transfer the received data to the entire population.
While the question on the effects of psilocybin and other psychedelic drugs in affective disorders remains open, scientists propose approach to its solution complex: recently, British researchers introduced a new method of imaging, which combines the analysis of neuronal activity and neurotransmitters, and it is said the action of the psychedelic on the brain.