Communications biology
July 26, 2023
Ivani Brys, Sebastian A Barrientos, Jon Ezra Ward et al.
33 citations
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.
Journal of Psychopharmacology
June 20, 2022
Luiz Antonio Miranda de Souza Duarte Filho, Isabela Araújo E Amariz, Rodolfo Hideki Vicente Nishimura et al.
12 citations
A standardized extract of Mimosa tenuiflora (SEMT), the plant used to prepare jurema wine, shows antidepressant-like effects in mice. The extract contains 24.74 ± 0.8 mg/g of N,N-dimethyltryptamine (DMT) and also yuremamine. In the tail suspension and forced swim tests, SEMT reduced immobility, indicating antidepressant-like activity, and this effect did not require harmine, a β-carboline. A sub-dose combination with ketamine also reduced immobility. SEMT enhanced head twitch behavior induced by 5-HTP, and ketanserin blocked its antidepressant-like effect, suggesting the effect involves activation of 5-HT2A/2C receptors.
Frontiers in neuroscience
January 1, 2023
Azat Nasretdinov, Sebastian A Barrientos, Ivani Brys et al.
6 citations
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.