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Ian Gregg

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

6 papers in the library · 677 citations · publishing 2021-2023

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.

Psilocybin induces rapid and persistent growth of dendritic spines in frontal cortex in vivo

bioRxiv (Cold Spring Harbor Laboratory) February 17, 2021 Ling-Xiao Shao, Clara Liao, Ian Gregg et al. 26 citations preprint

A single dose of psilocybin, a serotonergic psychedelic, caused a roughly 10% increase in the size and density of dendritic spines on layer 5 pyramidal neurons in the mouse medial frontal cortex. This structural remodeling began within 24 hours and persisted for at least one month, driven by an elevated rate of new spine formation. The drug also reduced stress-related behavioral deficits and increased excitatory neurotransmission. The findings demonstrate that psilocybin induces fast and enduring synaptic rewiring in the cortex, which may provide a structural basis for long-term integration of experiences and lasting therapeutic benefits.

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.

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.

Visualizing drug actions on dendrites: psilocybin and other classic psychedelics

January 1, 2023 Ling-Xiao Shao, Clara Liao, Ian Gregg et al.

Psychedelics like psilocybin can alter neuronal structure in the frontal cortex. Using two-photon microscopy in mice, psilocybin administration led to changes in dendritic spines, the tiny protrusions on neurons that receive signals from other neurons. The effects were compared with those of other psychoactive drugs, suggesting that psychedelics may have unique impacts on brain cell architecture. These findings indicate a potential mechanism for how psychedelics could influence brain function and behavior.