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Chloe Shevakh

Biological Psychiatry Laboratory and Hadassah BrainLabs, Center for Psychedelic Research, Hebrew University, Jerusalem, Israel.

4 papers in the library · 31 citations · publishing 2024-2025

Papers

Striking long-term beneficial effects of single dose psilocybin and psychedelic mushroom extract in the SAPAP3 rodent model of OCD-like excessive self-grooming

Molecular Psychiatry October 11, 2024 Michal Brownstien, Michal Lazar, Alexander Botvinnik et al. 23 citations

In mice lacking the SAPAP3 gene, which display excessive self-grooming and anxiety similar to human obsessive-compulsive disorder, a single injection of psilocybin or psychedelic mushroom extract reduced self-grooming by about 15-19% over 21 days, while vehicle-treated mice showed a 119% increase. The effects lasted up to 7 weeks in responsive mice, and non-responsive mice later treated with psilocybin also improved. The mushroom extract was superior for reducing head-body twitches and anxiety. These results support clinical trials of psilocybin for OCD.

Striking Long Term Beneficial Effects of Single Dose Psilocybin and Psychedelic Mushroom Extract in the SAPAP3 Rodent Model of OCD-Like Excessive Self-Grooming

bioRxiv (Cold Spring Harbor Laboratory) June 29, 2024 Michal Brownstien, Michal Lazar, Alexander Botvinnik et al. 5 citations preprint

In mice with a genetic deletion that causes excessive self-grooming and anxiety—behaviors resembling aspects of obsessive-compulsive disorder (OCD)—a single dose of psilocybin or psychedelic mushroom extract reduced self-grooming over 21 days, while vehicle-treated mice showed a 118.7% increase. Psilocybin and the extract both decreased self-grooming by about 15–19%, and improvements in secondary measures like twitches and anxiety were also significant. In responsive mice, benefits lasted up to 7 weeks. The extract was superior for alleviating head-body twitches and anxiety. These results support clinical trials of psilocybin for OCD.

Premorbid characteristics of the SAPAP3 mouse model of obsessive-compulsive disorder: behavior, neuroplasticity, and psilocybin treatment

The International Journal of Neuropsychopharmacology March 29, 2025 Michal Lazar, Michal Brownstien, Alexander Botvinnik et al. 3 citations

Mice lacking the SAPAP3 gene (SAPAP3-KO) develop excessive self-grooming at 4–6 months, modeling obsessive-compulsive disorder (OCD). Before that, juvenile (10–13 week) homozygous knockout mice showed anxiety-like behaviors—less time in open field centers and elevated plus maze open arms, fewer marbles buried, and fewer buried Oreos found—compared to wild-type mice. Psilocybin (4.4 mg/kg) did not improve these behaviors. In adult (but not juvenile) male homozygous knockout mice, levels of the synaptic proteins GAP43, synaptophysin, and SV2A increased across multiple brain regions; SV2A also increased in the frontal cortex of adult female homozygotes. These age-dependent protein changes may reflect compensatory plasticity linked to the OCD-like phenotype.

Premorbid Characteristics of the SAPAP3-Mouse Model of Obsessive-Compulsive Disorder: Behavior, Neuroplasticity, and Psilocybin Treatment

bioRxiv (Cold Spring Harbor Laboratory) September 23, 2024 Michal Lazar, Michal Brownstien, Alexander Botvinnik et al. preprint

Juvenile mice lacking the SAPAP3 gene, a model of obsessive-compulsive disorder (OCD), show anxiety-like behaviors before they develop the excessive self-grooming that mimics OCD compulsions. Compared to normal mice, these knockout mice spent less time in open areas, buried fewer marbles, and found fewer hidden objects. A single dose of psilocybin (4.4 mg/kg) did not reduce these anxiety-like behaviors. In adult but not juvenile male knockout mice, levels of several synaptic proteins (GAP43, synaptophysin, SV2A) were elevated across brain regions, suggesting compensatory plasticity changes that emerge with age. The findings parallel the clinical observation that anxiety often precedes OCD in humans and indicate that psilocybin's therapeutic effects may be age-dependent.