European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
June 1, 2019
Matthijs G Bossong, Hendrika H Van Hell, Chris D Schubart et al.
A single dose of THC, the main psychoactive ingredient in cannabis, increases blood flow (perfusion) in brain regions linked to the salience network—the bilateral insula, medial superior frontal cortex, and left middle orbital frontal gyrus—while decreasing connectivity between that last area and the precuneus. The perfusion increase in the left insula correlated with subjective changes in perception and relaxation. Genetic variation in the COMT Val158Met genotype modulated these effects: only Val/Met heterozygotes showed increased perfusion in the executive network after THC, suggesting that prefrontal dopamine levels influence susceptibility to cannabis's acute effects.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
July 1, 2018
R K Das, K Walsh, J Hannaford et al.
Blocking the reconsolidation of drinking-related reward memories is a potential strategy for treating alcohol use disorders, but few pharmacological options are available for humans. This study tested whether nitrous oxide (N2O), an NMDA receptor antagonist, could reduce drinking by interfering with memory reconsolidation in 60 hazardous drinkers. Participants retrieved alcohol memories either with or without prediction error, or retrieved non-alcohol memories with prediction error, then inhaled 50% N2O for 30 minutes. The manipulation did not reduce drinking as intended based on group assignment. However, when actual experience of prediction error was assessed, N2O reduced drinking in a retrieval- and prediction-error-dependent manner. These preliminary findings highlight the importance of verifying memory reactivation procedures and suggest further investigation of N2O as a reconsolidation-blocking agent.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
October 1, 2015
Miriam A Vogt, Anne S Vogel, Natascha Pfeiffer et al.
Ketamine is a fast-acting antidepressant but can cause psychosis-like side effects. The nitric oxide donor sodium nitroprusside (SNP) prevents such effects in rats and humans. In mice, pre-treatment with SNP (0.5-1 mg/kg) did not alter the antidepressant effect of ketamine (30 mg/kg) in the Porsolt Forced Swim Test, and SNP alone had no effect. This suggests the nitrinergic system may be differentially involved in ketamine's antidepressant versus psychotomimetic effects, though species differences cannot be ruled out.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
November 1, 2008
Pin-Yu Perera, Jack H Lichy, John Mastropaolo et al.
The Balb/c mouse strain is more sensitive than other strains to MK-801, a drug that blocks NMDA receptors, showing a higher threshold for seizures and irregular jumping behavior. This sensitivity suggests Balb/c mice may model psychosis-proneness. The study compared protein expression of NMDA receptor subunits in the hippocampus and cerebral cortex of Balb/c and NIH Swiss mice but found that differences in these subunits do not explain the behavioral differences.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
July 1, 2008
Simret Beraki, Alexander Kuzmin, Fadao Tai et al.
Repeated low-dose phencyclidine (PCP) impairs spatial learning and memory in mice without causing sensorimotor deficits, while higher doses produce severe motor disturbances that prevent testing. The atypical antipsychotic clozapine, but not the typical antipsychotic haloperidol, blocks the spatial impairment caused by low-dose PCP. This dissociation may help model declarative memory disturbances in schizophrenia and clarify differences between antipsychotic drug classes.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
August 1, 2003
E W P M Daenen, G Wolterink, J M Van Ree
Rats that received ibotenic acid lesions in the amygdala on day 7 of life, a proposed animal model of schizophrenia, showed a stronger behavioral response to phencyclidine (PCP) than sham-operated rats. PCP dose-dependently caused hyperactivity, stereotyped behavior, and social isolation in all rats, but the lesioned animals were hyperresponsive to the drug. This hyperresponsiveness supports the validity of the neonatal amygdala lesion model for studying schizophrenia-like symptoms.