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Richardson N Leão

5 papers in the library · 61 citations · publishing 2020-2026

Papers

Anxiety-like behavior induced by salicylate depends on age and can be prevented by a single dose of 5-MeO-DMT.

Experimental neurology April 1, 2020 Jessica Winne, Barbara C Boerner, Thawann Malfatti et al. 34 citations

Salicylate intoxication, which causes tinnitus and anxiety in humans, induces anxiety-like behavior and a specific brain oscillation called type 2 theta (theta2) in the hippocampus of young mice with normal hearing, but not in older mice. A single dose of the hallucinogenic compound 5-MeO-DMT prevents both the anxiety-like behavior and the increase in theta2 and slow gamma oscillations in the ventral hippocampus and medial prefrontal cortex after salicylate injection. These findings suggest that the anxiety triggered by salicylate depends on normal hearing and that hallucinogenic compounds may be effective for treating tinnitus-related anxiety.

Serotonergic psychedelic 5-MeO-DMT alters plasticity-related gene expression and generates anxiolytic effects in stressed mice.

Molecular psychiatry January 1, 2025 Margareth Nogueira, Daiane C Ferreira Golbert, Richardson Menezes et al. 18 citations

A single dose of the short-acting psychedelic 5-MeO-DMT alters expression of genes related to plasticity and neuronal activity in specific brain regions of mice, including the anterior cingulate cortex, basolateral amygdala, and ventral hippocampus. Immediate early genes Arc and Zif268 changed within hours, while TRIP8b, a modulator of neuronal activity, increased in the ventral hippocampus after five days. Behaviorally, 5-MeO-DMT produced mixed anxiety-reducing and anxiety-increasing effects in standard tests, but mice pre-treated with the compound and then exposed to acute stress showed lower corticosterone levels and strong anxiety-reducing effects. The findings suggest molecular pathways through which 5-MeO-DMT may produce anxiolytic effects.

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

Scientific reports May 17, 2024 Annie C Souza, Bryan C Souza, Arthur França et al. 7 citations

The psychedelic 5-MeO-DMT alters brain activity in rats by increasing delta waves and decreasing theta waves in the hippocampus, changes that are not explained by movement. It also reduces slow and mid gamma power and disrupts theta phase modulation. The overall brain state resembles patterns seen during slow-wave sleep and REM sleep, suggesting that the drug's effects involve mixing waking behavior with sleep-like neural oscillations.

Single-dose DMT reverses anhedonia and cognitive deficits via restoration of neurogenesis in a stress-induced depression model.

Translational psychiatry January 29, 2026 Rafael V Lima Da Cruz, Rêmullo B G de Miranda Costa, Gabriel M De Queiroz et al. 2 citations

A single dose of the psychedelic DMT reversed depression-like behavior and restored cognitive performance in male mice exposed to chronic stress, outperforming chronic fluoxetine across most measures. When given during the stress period, DMT reduced anhedonia but did not rescue cognitive deficits, indicating domain-specific long-lasting effects. All DMT regimens increased the integration of adult-born granule cells and reduced abnormally integrated cells in the brain, suggesting structural circuit repair. The role of the psychedelic experience remains uncertain because isoflurane anesthesia may have confounded results.

Effects of psychedelics on neurogenesis and brain plasticity: A systematic review

bioRxiv (Cold Spring Harbor Laboratory) July 20, 2023 Rafael V Lima Da Cruz, Richardson N Leão, Thiago C Moulin preprint

New neurons continue to be generated in the mammalian brain throughout life, a process linked to the HPA axis and mood disorders. Psychedelic compounds—including phenethylamines, tryptamines, cannabinoids, and others—have emerged as potential treatments for neuropsychiatric disorders, with evidence suggesting they increase adult neurogenesis. This systematic review examined 68 studies from a total of 205 articles, covering CB1 agonists, NMDA antagonists, harmala alkaloids, tryptamines, and entactogens. The findings describe how different psychedelics affect the birth of new neurons and brain plasticity, providing a comprehensive picture that may inform future therapeutic strategies for neuropsychiatric disorders.