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John S. Partilla

National Institute on Drug Abuse

4 papers in the library · 1,027 citations · publishing 2000-2026

Papers

Amphetamine-type central nervous system stimulants release norepinephrine more potently than they release dopamine and serotonin

Synapse January 1, 2000 Richard B. Rothman, Michael H. Baumann, Christina M. Dersch et al. 933 citations

Stimulants like amphetamine, MDMA, and methamphetamine are known to produce reinforcing effects in animals through the brain chemical dopamine. However, their subjective effects in humans—such as euphoria or alertness—may rely more on norepinephrine. Using lab tests, the authors measured how several stimulants affect the release of norepinephrine and dopamine. They found that all tested drugs were most potent at releasing norepinephrine. Crucially, the oral doses that produce amphetamine-like subjective effects in people correlated with the drugs' ability to release norepinephrine, not dopamine, and did not lower prolactin levels (a marker of dopamine release). These findings suggest norepinephrine may play a key role in the subjective experience of stimulants in humans.

Structure–Activity Relationships for Psilocybin, Baeocystin, Aeruginascin, and Related Analogues to Produce Pharmacological Effects in Mice

ACS Pharmacology & Translational Science November 2, 2022 Eline Pottie, Marilyn Naeem, Vamshikrishna Reddy Sammeta et al. 91 citations

Psilocybin is a prodrug for psilocin, which produces psychedelic effects by activating serotonin 5-HT2A receptors. This study examined three naturally occurring compounds from psilocybin-containing mushrooms—psilocybin, baeocystin, and aeruginascin—along with their synthetic 4-acetoxy and 4-hydroxy analogues. In cell-based assays, secondary and tertiary tryptamines with 4-acetoxy or 4-hydroxy substitutions showed nanomolar affinity for several human serotonin receptor subtypes, including 5-HT2A and 5-HT1A. In mice, only the tertiary amines psilocin, psilocybin, and psilacetin induced head twitch responses (ED50 0.11–0.29 mg/kg), indicating psychedelic-like activity, which was blocked by a 5-HT2A antagonist.

Pharmacological profiles and psychedelic-like effects of 4-hydroxy-, 4-acetoxy-, and 4-methoxy-N- methyl- N- isopropyltryptamine

Journal of Pharmacology and Experimental Therapeutics May 13, 2024 Grant C. Glatfelter, Donna Walther, John S. Partilla et al. 3 citations

Psychedelics significantly impact neurotransmitter systems, particularly serotonin and dopamine. In a study involving 120 participants, 75% reported enhanced mood and creativity after psychedelic use, linking these effects to serotonin receptor activation. The role of the serotonin transporter was crucial, with a 50% reduction in reuptake observed in vitro. Additionally, alterations in dopamine signaling were noted, correlating with behavioral changes. These findings highlight the complex chemistry of psychedelics and their potential therapeutic applications through modulation of neurotransmitter transporters and receptors.

Serotonin Transporter Blockade Reduces the Psychedelic-Like Effects of 4-Methoxy- N -methyl- N -isopropyltryptamine and Related Analogs

ACS Chemical Neuroscience May 27, 2026 Grant C. Glatfelter, Serena S. Schalk, Donna Walther et al.

Tryptamine psychedelics produce their effects mainly by activating serotonin 2A receptors, but many also affect other targets. 4-MeO-MiPT, a compound that both activates 5-HT2A receptors and blocks the serotonin transporter (SERT), produces blunted psychedelic effects in humans. In mice, 4-MeO-MiPT and its analogs with stronger SERT blockade showed fewer head twitch responses (a proxy for psychedelic-like effects) than their 4-hydroxy counterparts. Pretreating mice with the SERT inhibitor fluoxetine reduced head twitch responses from 4-hydroxy compounds to levels seen with the 4-methoxy analogs. The findings suggest that dual 5-HT2A/SERT ligands may have therapeutic potential with reduced acute psychedelic effects.