European journal of pharmacology
March 5, 2024
Hugo R Arias, Deborah Rudin, Dustin J Hines et al.
12 citations
A non-hallucinogenic compound derived from ibogamine, DM506, produces anxiolytic- and sedative-like effects in mice without causing hallucinogenic head-twitch responses. At 15 mg/kg, DM506 induces both acute and long-lasting anxiety-reducing behavior in naive and stressed mice. Repeated 5 mg/kg doses show no cumulative effects or side effects. Higher doses (40 mg/kg) cause sedation that is blocked by the 5-HT2A receptor antagonist volinanserin. DM506 binds to human 5-HT2A (Ki = 24 nM) and 5-HT2B (Ki = 16 nM) receptors, activating them with EC50 values of 9 nM and 3 nM, respectively, acting as a partial agonist compared to the full agonist DOI. Electroencephalography shows increased transition from alert to deep-sleep brain wave activity.
The international journal of biochemistry & cell biology
November 1, 2024
Jasmine Jade Butler, Daria Ricci, Chloé Aman et al.
8 citations
Classical psychedelics, which bind to serotonin receptors (5-HTRs), have complex and region-specific effects on the activity of monoaminergic neurons. They can inhibit the firing of serotonergic neurons without necessarily reducing serotonin release in all brain regions, and similarly inhibit noradrenergic neuron spontaneous activity without consistently decreasing noradrenaline release. Their influence on dopaminergic systems is also complex, with opposing effects depending on the specific serotonin receptor subtype and the brain state. Overall, there is no single, clear neuronal signature for how psychedelics affect monoamine systems; instead, the effects are state-dependent and region-dependent.
Progress in neuro-psychopharmacology & biological psychiatry
July 13, 2025
Jasmine Jade Butler, Margherita Virgili, Giuseppe Di Giovanni et al.
5 citations
Serotonergic psychedelics disrupt the normally organized pattern of correlations among serotonin, dopamine, and noradrenaline concentrations across 28 brain regions in mice during forced exploratory behavior. Both the 5-HT2A receptor agonist TCB-2 and the antagonist MDL-100,907 decreased correlations between regional neurochemical levels, while combining them partially restored those correlations. TCB-2 dose-dependently reduced serotonin turnover across all brain regions and dopamine turnover in the striatum, and enhanced markers of dopamine and noradrenaline systems in the anterior cingulate cortex. MDL-100,907 alone had minimal effects on monoamine levels but reduced TCB-2-induced head twitches and increased monoamine concentrations in the anterior cingulate cortex without affecting the serotonin turnover decrease. The functional connectivity of monoaminergic systems during exploration is highly sensitive to modulation through 5-HT2A receptor activation or blockade.