European journal of pharmacology
December 15, 2024
Ming-Ming Zhao, Ting-Ting Zhu, Dan Xu et al.
14 citations
Arketamine, the (R)-enantiomer of ketamine, reduces damage to the myelin sheath and promotes its repair in the brains of mice treated with cuprizone, a chemical that induces demyelination. The beneficial effects occur through a mechanism dependent on transforming growth factor β1 (TGF-β1). Blocking the TGF-β1 receptor with RepSox prevented arketamine's protective effects. Directly administering TGF-β1 intranasally also reduced demyelination and enhanced remyelination in the corpus callosum. These findings suggest that arketamine's effects on myelin repair rely on TGF-β1 signaling, pointing to potential therapeutic targets for demyelinating diseases like multiple sclerosis.
Progress in neuro-psychopharmacology & biological psychiatry
January 10, 2025
Ting-Ting Zhu, Ming-Ming Zhao, Dan Xu et al.
5 citations
Postoperative cognitive dysfunction (POCD) involves declines in memory, attention, and executive abilities after surgery, with no effective drugs available. In a mouse model of POCD, a single injection of arketamine (10 mg/kg) improved cognitive function and reduced demyelination in the corpus callosum. Blocking TGF-β receptor 1 with RepSox (10 mg/kg) prevented these benefits, while intranasal TGF-β1 (3.0 μg/kg) alone alleviated cognitive impairments and demyelination. The findings indicate arketamine acts through a TGF-β1-dependent mechanism, suggesting it as a potential treatment for POCD.
Progress in neuro-psychopharmacology & biological psychiatry
March 20, 2025
Yong Yue, Xiayun Wan, Guilin Liu et al.
4 citations
The gut-brain axis, specifically the subdiaphragmatic vagus nerve, is critical for MDMA's effects on the oxytocin system in rats. Cutting this nerve (subdiaphragmatic vagotomy) lowered baseline oxytocin levels in the blood and reduced oxytocin expression in the paraventricular and supraoptic nuclei of the hypothalamus. It also dampened MDMA-induced increases in blood oxytocin and the expression of oxytocin and c-Fos in those brain regions. The findings suggest the vagus nerve mediates brain-body communication that underlies MDMA's pharmacological actions on oxytocin.
Progress in neuro-psychopharmacology & biological psychiatry
January 10, 2025
Dan Xu, Akifumi Eguchi, Rumi Murayama et al.
4 citations
Repeated oral administration of MDMA (10 mg/kg/day for 14 days) to male rats significantly altered gut microbiota composition in the small intestine, cecum, and colon, with distinct effects in each region. Analysis of microbial functional capabilities indicated shifts in several metabolic pathways. Untargeted metabolomics showed that MDMA changed levels of two metabolites in the colon—ferulic acid and methylmalonic acid—without affecting levels in blood, small intestine, or cecum. Methylmalonic acid levels in the colon positively correlated with the bacteria Lawsonibacter and Oscillibacter. These results suggest that repeated MDMA treatment can modify gut microbiota across intestinal regions, which may contribute to its pharmacological effects.
Translational Psychiatry
May 20, 2026
Xin Ding, Rumi Murayama, Yi Cai et al.
1 citation
The drug combination KarXT (xanomeline plus trospium) reverses cognitive deficits caused by phencyclidine (PCP) in adult male mice, and this effect is linked to changes in gut and lung microbiota. PCP disrupted recognition memory and caused region-specific imbalances in microbes, especially in the small intestine and cecum. KarXT restored memory and normalized several bacterial species elevated by PCP, including Bacteroides fragilis and Veillonella ratti. Restoration of certain lung and gut microbes correlated with improved memory. The findings suggest that KarXT's cognitive benefits involve microbial modulation, which may guide efforts to reduce gastrointestinal side effects in muscarinic therapies for schizophrenia.
Clinical psychopharmacology and neuroscience : the official scientific journal of the Korean College of Neuropsychopharmacology
May 31, 2026
Yong Yue, Yi Cai, Rumi Murayama et al.
Gut bacteria contribute to baseline central oxytocin signaling in rats, but are not necessary for the acute oxytocin release triggered by MDMA. Male rats given broad-spectrum antibiotics for seven days showed enlarged ceca, confirming microbiome disruption, yet maintained stable body weight. Baseline oxytocin expression in the paraventricular and supraoptic nuclei of the hypothalamus was significantly reduced after antibiotic treatment, while peripheral oxytocin levels remained unchanged. MDMA administration increased central oxytocin expression similarly in both antibiotic-treated and control rats, and MDMA-induced peripheral oxytocin levels also did not differ between groups. The findings indicate that gut microbiota help maintain central oxytocin under normal conditions but are not required for MDMA's oxytocin-activating effects.