From Medical Xpress:
LSD is known to cause changes in consciousness, including “ego-dissolution”, or a loss of the sense of self. Despite a detailed knowledge of the action of LSD at specific serotonin receptors, it has not been understood how this these pharmacological effects can translate into such a profound effect on consciousness Today, a new report presented at the annual meeting of the American College of Neuropsychopharmacology in Hollywood, Florida, provides evidence to show that LSD reduces connectivity within brain networks, or the extent to which nerve cells or neurons within a network fire in synchrony. LSD also seems to reduce the extent to which separate brain networks remain distinct in their patterns or synchronization of firing. Overall, LSD interferes with the patterns of activation in the different brain networks that underlie human thought and behavior.
In this new study, Dr. Robin Carhart-Harris and his colleagues at Imperial College London did sequential brain scans of 20 healthy volunteers over 6 hours, using functional magnetic resonance imaging (fMRI), which maps brain activity by detecting changes in blood flow, and magnetoencephalography (MEG), a technique that images brain function by recording magnetic fields produced by electrical currents occurring in the brain. Using fMRI, the investigators showed that LSD led to a more chaotic brain state not entirely dissimilar to what is seen in the prodromal phase of psychosis.
Specifically, neurons that were supposed to fire together within a network fell out of synchrony, while networks that are normally distinct started to overlap in…