Progress in neuro-psychopharmacology & biological psychiatry
March 20, 2025
Kristýna Štefková-mazochová, Hynek Danda, Vladimír Mazoch et al.
3 citations
Methoxphenidine (MXP), a new psychoactive substance, rapidly crosses the blood-brain barrier in Wistar rats, reaching peak concentrations in serum and brain 30 minutes after injection, with a half-life of 2.15 hours. Low to moderate doses (10-20 mg/kg) increase locomotor activity in an open field test, while a higher dose (40 mg/kg) decreases it. All doses disrupt sensorimotor gating (prepulse inhibition), an effect linked to psychosis. MXP shows moderate acute toxicity with an estimated LD50 of 500 mg/kg subcutaneously. The drug exhibits a profile similar to dissociative anesthetics, producing stimulant and anxiogenic effects at lower doses and sedative effects at higher doses, indicating risks of serious adverse health outcomes from recreational use.
The international journal of neuropsychopharmacology
August 1, 2025
Klára Šíchová, Barbara Mallarino, Lucie Janečková et al.
1 citation
Hexahydrocannabinol (HHC), a new psychoactive substance used as a legal alternative to ∆9-tetrahydrocannabinol, crosses the blood-brain barrier, exhibits mild toxicity, and induces behavioral effects similar to tetrahydrocannabinol in male Wistar rats. A 1:1 mixture of (9R)-HHC and (9S)-HHC was given at doses of 1, 5, and 10 mg/kg. Two hours after the highest dose, peak concentrations appeared in blood and brain tissue. The OECD 423 test classified HHC as Category 4, with an estimated lethal dose of 1000 mg/kg. Compared to controls, 10 mg/kg HHC reduced movement, increased anxiety, and impaired sensory processing, highlighting dose-dependent anxiogenic properties and impact on information processing.
Addiction Biology
March 1, 2026
Isis Koutrouli, Vojtěch Brejtr, Marek Schwendt et al.
Psilocybin and ibogaine, given in a dose-escalation protocol, facilitated extinction learning in male rats that had self-administered cocaine. Psilocybin reduced active lever pressing one day after the second dose, with a nonsignificant reduction after the first dose; ibogaine significantly reduced pressing even after the first administration. Neither drug significantly altered cue-induced reinstatement of drug-seeking, though psilocybin showed a trend toward attenuation. The treatments had no side effects on general locomotor activity or anxiety-like behavior in the open field test. These results suggest psilocybin and ibogaine may support extinction learning and possibly protect against relapse, warranting further research into their antiaddictive potential.