Psychopharmacology

Abstract Rationale The anthelmintic agent, levamisole, is a cocaine adulterant that causes serious adverse effects in humans. A number of hypotheses have been proposed to explain why levamisole is used as an adulterant. Here, we examined whether levamisole might enhance acute pharmacological effects of cocaine. Methods Levamisole and its phase I metabolites were tested for in vitro activity at mo…

Abstract Rationale The telescoping effect, where females progress more rapidly than males from initial drug use to developing a substance use disorder, is a widely cited sex/gender difference, yet its molecular basis remains unknown. Objectives To test whether calcium-permeable AMPA receptors (CP-AMPARs) in the nucleus accumbens (NAc) contribute to the development of enhanced motivation for cocai…

Abstract Rationale Delta-9-tetrahydrocannabinol (Δ9-THC) has been reported to evoke psychedelic-like experiences at high doses in some individuals. However, the doses of Δ9-THC that occasion such effects and the phenomenology of these experiences are poorly understood. Objectives This brief report presents preliminary findings from a pilot human laboratory study that directly compared the acute e…

Abstract Rationale Sex differences in the effects of cannabis have been demonstrated in animals, though the human evidence is more equivocal. In particular, more work is needed to better understand interactions between sex and dose in determining acute pharmacological effects of cannabis, especially at higher potencies of Δ 9 -tetrahydrocannabinol (THC). Objectives Sex differences were examined f…

RATIONALE: Access to alternative non-drug rewards is known to influence alcohol use, yet how chronic exposure affects behavioral allocation under concurrent choice conditions remains poorly understood. OBJECTIVES: This study examined the effects of chronic, binge-like ethanol vapor on ethanol self-administration and behavioral allocation in a concurrent operant choice paradigm offering sweetened …

RATIONALE: Military personnel are exposed to bouts of acute stress during their careers, in which cognitive processes associated with decision-making might simultaneously suffer. Currently, it is still unclear how hormones and neurotransmitters involved in the acute stress response specifically affect these decision-making subprocesses, particularly in the military. OBJECTIVES: We aimed to expose…

Abstract Rationale and objectives Negative self-referential emotions such as embarrassment and shame play a key role in the psychopathology of psychiatric disorders but are often insufficiently addressed by standard treatments. Psychedelics such as ayahuasca – an Amazonian plant decoction containing the psychedelic N,N-dimethyltryptamine (DMT) and harmala alkaloids, have been proposed to positive…

Abstract Rationale The ongoing epidemic of nicotine vaping use in adolescents and young adults presents a significant health concern, yet the long-term effects of nicotine vaping remain largely unknown. Objective The present study aimed to investigate how nicotine vapor intake early in life influences reward-seeking behavior immediately after exposure and later in adulthood. Methods Experiment 1 …

RATIONALE: Mu opioid receptor (MOR) analgesics like morphine have high intrinsic MOR efficacy but produce side effects. Lower efficacy MOR agonists like buprenorphine can produce analgesia with improved safety. We recently described a series of novel phenylmorphan-based MOR agonists with graded MOR efficacies, including several with sub-buprenorphine efficacies, and we described their acute effec…

RATIONALE: Fatal opioid overdoses involving synthetic opioids have increased >10-fold over the past 8 years. Fentanyl, a potent synthetic opioid acting at the mu-opioid receptor (MOR), has largely replaced heroin as the predominant illicit opioid available. Various analogs have been synthesized from the fentanyl scaffold, including 2-furanylfentanyl, one of the most trafficked analogs from 2019 t…

Abstract Rationale People who use cannabis often report using it to improve sleep and/or manage mental health symptoms. Cannabis products differ in their typical cannabinoid composition, particularly in their relative THC and CBD content, which may impact health outcomes differently. Objectives This naturalistic study investigated associations between cannabis use and related problems, sleep qual…