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Leonard L. Howell

10 papers in the library · 294 citations · publishing 2008-2019

Papers

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Sensitization to the prosocial effects of 3,4-methylenedioxymethamphetamine (MDMA).

Neuropharmacology June 2019 Daniel W Curry, Laís F. Berro, Andie R Belkoff et al.

The recreational drug 3,4-methylenedioxymethamphetamine (MDMA) has well documented prosocial effects and is currently under clinical investigation as a treatment for patients with PTSD, autism, and other conditions. Early clinical trials have found that MDMA-assisted therapy may have robust long-lasting therapeutic effects, yet the mechanism by which acute treatments produce these long-term...

DOI: 10.1016/j.neuropharm.2019.03.017 (opens in new tab) Full text (opens in new tab) MDMA 3,4-methylenedioxymethamphetamine 5-ht2a Sensitization +1

(±)-MDMA and its enantiomers: potential therapeutic advantages of R(-)-MDMA.

Psychopharmacology February 2018 Elizabeth G Pitts, Daniel W Curry, Karly N Hampshire et al.

The use of (±)-3,4-methylenedioxymethamphetamine ((±)-MDMA) as an adjunct to psychotherapy in the treatment of psychiatric and behavioral disorders dates back over 50 years. Only in recent years have controlled and peer-reviewed preclinical and clinical studies lent support to (±)-MDMA's hypothesized clinical utility. However, the clinical utility of (±)-MDMA is potentially mitigated by a range...

Ketamine and pharmacological imaging: use of functional magnetic resonance imaging to evaluate mechanisms of action.

Behavioural Pharmacology December 2017 Eric A Maltbie, Gopinath S Kaundinya, Leonard L. Howell

Ketamine has been used as a pharmacological model for schizophrenia as subanesthetic infusions have been shown to produce temporary schizophrenia-like symptoms in healthy humans. More recently, ketamine has emerged as a potential treatment for multiple psychiatric disorders, including treatment-resistant depression and suicidal ideation. However, the mechanisms underlying both the...

3,4-Methylenedioxymethamphetamine Increases Affiliative Behaviors in Squirrel Monkeys in a Serotonin 2A Receptor-Dependent Manner

Neuropsychopharmacology September 1, 2017 Elizabeth G Pitts, Adelaide R. Minerva, Erika B Chandler et al. 20 citations

3,4-Methylenedioxymethamphetamine (MDMA) increases sociality in humans and animals. Release of serotonin (5-HT) is thought to have an important role in the increase in social behaviors, but the mechanisms underlying these effects are poorly understood. Despite the advantages of nonhuman primate models, no studies have examined the mechanisms of the social effects of MDMA in nonhuman primates....

Inhibition of serotonin transporters disrupts the enhancement of fear memory extinction by 3,4-methylenedioxymethamphetamine (MDMA)

Psychopharmacology July 24, 2017 Matthew B Young, Seth D. Norrholm, Lara M. Khoury et al. 103 citations

We validate enhancement of fear memory extinction by MDMA in a translational behavioral model, and reveal the importance of 5-HTT and 5-HT2A receptors to this effect. These observations support future clinical research of MDMA as an adjunct to exposure therapy, and provide important pharmacological considerations for clinical use in a population frequently treated with 5-HTT inhibitors.

DOI: 10.1007/s00213-017-4684-8 (opens in new tab) Full text (opens in new tab) MDMA Serotonin transporter Extinction optical mineralogy Pharmacology +2

3,4-Methylenedioxymethamphetamine facilitates fear extinction learning

Translational Psychiatry September 15, 2015 Matthew B Young, Raül Andero, Kerry J. Ressler et al. 137 citations

Abstract Acutely administered 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’) has been proposed to have long-term positive effects on post-traumatic stress disorder (PTSD) symptoms when combined with psychotherapy. No preclinical data support a mechanistic basis for these claims. Given the persistent nature of psychotherapeutic gains facilitated by MDMA, we hypothesized that MDMA improves...

Neuropharmacology of 3,4‐methylenedioxymethamphetamine (MDMA, “ecstasy”) and its stereoisomers: a combined positron emission tomography and functional magnetic resonance imaging study in rhesus monkeys

The FASEB Journal April 1, 2011 Kevin S. Murnane, Leonard L. Howell

3,4-methylenedioxymethamphetamine (MDMA) is a substituted amphetamine derivative that is widely abused as the street drug “ecstasy”. Despite its high abuse liability, the neuropharmacology of MDMA remains poorly understood. In the present study, functional magnetic resonance imaging (fMRI) was used in fully conscious rhesus monkeys to characterize the neuroactivational effects of MDMA and its...

Reinstatement of extinguished amphetamine self-administration by 3,4-methylenedioxymethamphetamine (MDMA) and its enantiomers in rhesus monkeys.

Psychopharmacology May 2010 Jessica McClung, William E Fantegrossi, Leonard L. Howell

The effectiveness of MDMA and its enantiomers to reinstate responding previously maintained by drug self-administration has not been thoroughly investigated. The present study was designed to compare the reinstatement effects of amphetamine, the piperazine-analog BZP, SR(+/-)-MDMA, S(+)-MDMA, R(-)-MDMA, and fenfluramine on behavior maintained under a second-order schedule of intravenous...

Discriminative stimulus effects of psychostimulants and hallucinogens in S(+)-3,4-methylenedioxymethamphetamine (MDMA) and R(-)-MDMA trained mice.

Journal of Pharmacology and Experimental Therapeutics November 1, 2009 Kevin S. Murnane, Naoki Murai, Leonard L. Howell et al. 34 citations

3,4-Methylenedioxymethamphetamine (MDMA) is a substituted phenethylamine more commonly known as the drug of abuse "ecstasy." The acute and persistent neurochemical effects of MDMA in the mice are distinct from those in other species. MDMA shares biological effects with both amphetamine-type stimulants and mescaline-type hallucinogens, which may be attributable to distinct effects of its two...

Discriminative stimulus effects of hallucinogens and psychostimulants in S(+)‐MDMA, and R(−)‐MDMA trained mice

The FASEB Journal March 1, 2008 Kevin Sean Murnane, Leonard L. Howell, William E Fantegrossi

3,4‐Methylenedioxymethamphetamine (MDMA) is an amphetamine derivative with increasingly widespread abuse. MDMA has been difficult to classify as a stimulant or hallucinogen because it shares effects with both drug classes. Furthermore, racemic MDMA is composed of two isomers that vary in terms of behavioral effects rather than simple potency differences. Specifically, the R(−) isomer of MDMA...