The Group for Integrative Neurophysiology and Neurotechnology, Department of Experimental Medical Science, Lund University, Lund, Sweden. par.halje@med.lu.se.
2 papers in the library · 39 citations · publishing 2023
Psychedelics like LSD, DOI, ketamine, and PCP produce profound changes in perception and cognition by inducing synchronized high-frequency oscillations across multiple brain regions. In rats, these drugs caused near-zero phase delays (<1 ms) in the ventral striatum and cortical areas, indicating hypersynchrony that likely disrupts information integration across neural systems. This shared pattern, despite different firing rate effects on interneurons and principal cells, suggests a key mechanism behind altered states of consciousness. Similar hypersynchrony may contribute to hallucinations and delusions in psychotic disorders, offering potential targets for new antipsychotic treatments.
LSD and ketamine produce altered brain states through different underlying mechanisms. In rodents, ketamine increased neuronal activity (indicated by shifts in local field potential power) but reduced connectivity between brain structures, while LSD also reduced connectivity but without a change in broadband power. The findings help bridge human imaging studies, which show altered functional connectivity, with invasive animal recordings that reveal high-frequency oscillations. Understanding these distinct neurophysiological signatures may clarify how classic psychedelics and dissociative anesthetics affect the brain, informing their potential therapeutic uses for psychiatric conditions.