Psychedelics and psychostimulants produce subjective and often positive affective effects in humans. In rats, positive affective states are often associated with frequency-modulated ultrasonic vocalizations (USVs). We examined whether the hallucinogenic 2,5-dimethoxy-4-iodoamphetamine (DOI; 1.25-2.5 mg/kg) and LSD (0.04-0.08 mg/kg), the non-hallucinogenic lisuride (0.03 or 0.3 mg/kg) and the...
Ketamine, known for its rapid-acting antidepressant effects, is often coadministered with other psychoactive drugs, including opioids and cannabinoids, in both clinical and recreational settings. We investigated whether ketamine (R-, S-, or racemic R, S-) isoforms alter the subjective effects of morphine or Δ9-tetrahydrocannabinol (THC) and whether the interoceptive effects of ketamine overlap...
Background: In clinical studies, psychedelics including psilocybin and D-lysergic acid diethylamide (LSD) demonstrate rapid and persistent antidepressant effects. Since the effective treatment with psychedelics is usually provided with psychotherapy, it is debatable whether their prolonged efficacy can be observed in infrahuman species. Preclinical reports on psychedelics’ effects most often...
(S)-ketamine-induced rapid-acting antidepressant effects have revolutionized the pharmacotherapy of major depression; however, this medication also produces psychotomimetic effects such as timing distortion. While (R)-ketamine produces fewer dissociative effects, its antidepressant actions are less studied. Depression is associated with time overestimation (i.e., subjectively, time passes...
Time underestimation produced by (S)-ketamine could be associated with its antidepressant effects; however, it was accompanied with severe behavioral disruption. We also hypothesize that behavioral disruption produced by psychedelics objectively reflects their psychotomimetic-like actions.