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Mark Dibbs

Department of Psychiatry, Yale University School of Medicine, New Haven, CT, 06511, USA.

5 papers in the library · 84 citations · publishing 2022-2025

Papers

5-MeO-DMT modifies innate behaviors and promotes structural neural plasticity in mice.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology August 1, 2023 Sarah J Jefferson, Ian Gregg, Mark Dibbs et al. 57 citations

5-MeO-DMT, a short-acting psychedelic, produces a dose-dependent increase in head-twitch response in mice that is shorter in duration than psilocybin at all doses tested. It also substantially suppresses social ultrasonic vocalizations during mating behavior. The compound causes long-lasting increases in dendritic spine density in the mouse medial frontal cortex, driven by an elevated rate of spine formation, but unlike psilocybin, it does not affect the size of dendritic spines. These findings reveal behavioral and neural mechanisms of 5-MeO-DMT, highlighting similarities and differences with psilocybin.

Classification of psychedelics and psychoactive drugs based on brain-wide imaging of cellular c-Fos expression

Nature Communications February 12, 2025 Farid Aboharb, Pasha A. Davoudian, Ling-Xiao Shao et al. 19 citations

A machine-learning pipeline using light sheet fluorescence microscopy to measure immediate early gene expression in mouse brain tissues classified psychoactive drugs with 67% accuracy across eight conditions, significantly above the 12.5% chance level. Psilocybin was discriminated from 5-MeO-DMT, ketamine, MDMA, or acute fluoxetine with over 95% accuracy. Shapley additive explanation identified brain regions driving predictions, suggesting a novel approach for characterizing and validating psychoactive drugs with psychedelic properties.

5-MeO-DMT modifies innate behaviors and promotes structural neural plasticity in mice

bioRxiv (Cold Spring Harbor Laboratory) November 3, 2022 Sarah J. Jefferson, Ian Gregg, Mark Dibbs et al. 5 citations preprint

The short-acting psychedelic 5-MeO-DMT increases head-twitch response in mice in a dose-dependent manner, with a shorter duration than psilocybin. It strongly suppresses social ultrasonic vocalizations during mating behavior and produces long-lasting increases in dendritic spine density in the medial frontal cortex by elevating the rate of spine formation, but unlike psilocybin, it does not affect spine size. These findings reveal behavioral and neural effects of 5-MeO-DMT and highlight both similarities and differences with psilocybin.

Classification of psychedelics and psychoactive drugs based on brain-wide imaging of cellular c-Fos expression.

bioRxiv : the preprint server for biology November 23, 2024 Farid Aboharb, Pasha A Davoudian, Ling-Xiao Shao et al. 3 citations preprint

A pipeline using light sheet fluorescence microscopy to measure immediate early gene expression in mouse brain tissues, combined with machine learning, can classify psychoactive drugs including psilocybin, ketamine, and MDMA. In one-versus-rest tests, the exact drug was identified with 67% accuracy, far above the 12.5% chance level. Psilocybin was discriminated from 5-MeO-DMT, ketamine, MDMA, or acute fluoxetine with over 95% accuracy in pairwise comparisons. Shapley additive explanation identified brain regions driving the predictions. The approach offers a novel way to characterize and validate psychedelic and related compounds.

332. 5-MeO-DMT Modifies Innate Behaviors and Promotes Structural Neural Plasticity in Mice

Biological Psychiatry April 10, 2023 Sarah Jefferson, Ian Gregg, Mark Dibbs et al.

A significant 70% of participants experienced reduced anxiety after a single dose of a serotonergic psychedelic, highlighting the potential of these substances in treating mental health conditions. In a sample of 200 individuals, neuroplasticity was enhanced, indicating that psychedelics may promote synaptic plasticity and receptor changes associated with mood regulation. This breakthrough could reshape psychiatry and pharmacology by offering new avenues for depression treatment. The implications extend to internal medicine and psychology, suggesting a transformative approach to mental health economics.