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Adriano B. L. Tort

4 papers in the library · 140 citations · publishing 2013-2024

Papers

Ketamine alters oscillatory coupling in the hippocampus

Scientific Reports August 2, 2013 Fábio V. Caixeta, Alianda Maira Cornélio, Robson Scheffer-Teixeira et al. 134 citations

Blocking NMDA receptors with ketamine alters how different brain rhythms interact in the hippocampus, a region critical for memory and attention. In awake rats, ketamine (25, 50, and 75 mg/kg) increased fast brain oscillations (gamma and high-frequency oscillations) across all layers of the CA1-dentate axis, while changes in slower theta waves depended on location. Ketamine also increased phase coherence of fast oscillations across hippocampal layers. The coupling between theta waves and fast oscillations changed in a dose-dependent way: theta-high-frequency coupling increased at all doses, but theta-gamma coupling increased only at the lowest dose and was disrupted at the highest dose. These findings indicate that NMDA receptor blockade disrupts neural coordination patterns linked to cognitive functions impaired in schizophrenia.

Gamma band alterations and REM-like traits underpin the acute effect of the atypical psychedelic ibogaine

bioRxiv (Cold Spring Harbor Laboratory) June 29, 2020 Joaquín González, Matías Cavelli, Santiago Castro‐zaballa et al. 5 citations preprint

Ibogaine, a psychedelic alkaloid with anti-addictive properties, produces a waking state that shares brain-wave traits with REM sleep. In rats, ibogaine increased gamma oscillation power in the brain but made those oscillations less coherent and less complex than normal waking levels. This pattern mirrors REM sleep features within the gamma frequency band, providing biological evidence for the long-standing hypothesis that ibogaine induces a dream-like state while awake—a phenomenon called oneirogenesis. The findings offer an empirical basis for understanding how ibogaine's unique subjective effects may contribute to its anti-addictive potential.

5-MeO-DMT induces sleep-like LFP spectral signatures in the hippocampus and prefrontal cortex of awake rats

bioRxiv (Cold Spring Harbor Laboratory) June 5, 2023 Annie Da Costa Souza, Bryan Da Costa Souza, Arthur S. C. França et al. preprint

The psychedelic 5-MeO-DMT increases delta power and decreases theta power in the hippocampus of freely moving rats, effects not explained by changes in locomotion. It also dose-dependently reduces slow and mid gamma power and theta phase modulation. The overall spectral profile of awake behavior after 5-MeO-DMT resembles electrophysiological states seen during slow-wave sleep and REM sleep. These findings suggest that classical psychedelics may integrate waking behaviors with sleep-like neural activity patterns.