Psychedelic medicine (New Rochelle, N.Y.)
June 1, 2024
Abshir S Adam, Kayleigh S LaMalfa, Yasaman Razavi et al.
6 citations
MDMA produces dose-dependent increases in reward responsivity, a measure of anhedonia, in rats, along with dose-dependent deficits in attention and short-term memory, and increases in prosocial interaction in male but not female rats. The desirable prohedonic effects and undesirable cognitive disruptions do not persist beyond 24 hours. These results characterize MDMA as a promising prohedonic treatment despite short-lived cognitive impairment following acute administration.
British journal of pharmacology
November 1, 2025
Yasaman Razavi, Stephen J Kohut, Jack Bergman et al.
1 citation
Adolescent monkeys exposed daily to the cannabis compound Δ9-THC for six months, then tested about a year later as adults on a touchscreen attention task, required higher acute doses of Δ9-THC to impair their performance compared with animals that had not been exposed during adolescence. The impairment itself was dose-related and occurred whether the drug was given by injection or orally, though potency and timing differed. These results suggest that heavy cannabis use during adolescence can produce a lasting tolerance that persists into adulthood, even after a long period of abstinence.
bioRxiv : the preprint server for biology
January 24, 2026
Kwang-Hyun Hur, Lisa D Nickerson, Jack Bergman et al.
THC, the psychoactive compound in cannabis, selectively amplifies behavioral and brain responses to cues that predict rewards, without affecting responses to neutral cues or baseline reward consumption. In squirrel monkeys, a low dose of THC (3 μg/kg) increased conditioned approach behavior toward a visual stimulus associated with food delivery. Functional MRI showed that THC enhanced activity in reward-related brain regions—anterior cingulate cortex, striatum, hippocampus, and substantia nigra-ventral tegmental area (SN-VTA)—while leaving visual and motor cortices unaffected. Resting-state connectivity analyses revealed that THC strengthened communication within mesocorticolimbic networks, with the SN-VTA acting as a central hub. These findings indicate that THC boosts incentive salience and motivational drive toward reward-associated stimuli through selective modulation of this circuitry.