Behavioural Pharmacology
June 1, 2017
Jeremy I Webster, David N. Harper, Susan Schenk
Studies that have attributed the discriminative stimulus effects of ±3,4-methylenedioxymethamphetamine (MDMA) to serotonergic mechanisms typically use a relatively low training dose of 1.5 mg/kg. The role of serotonin in the discriminative stimulus effects of higher doses of MDMA is, however, unknown. Separate groups of rats were trained to discriminate MDMA (1.5 or 3.0 mg/kg) from saline using...
Addiction Biology
October 13, 2011
David N. Harper
11 citations
Evidence suggests that acute exposure to (+/-)3,4-methylenedioxymethamphetamine (MDMA) produces qualitatively similar effects on recognition task performance as other stimulant-type drugs. The current study examined whether there was a similar neurochemical basis to these memory effects by examining the effects of a D1 receptor antagonist (SCH23390) and D2 antagonist (eticlopride) on MDMA- or...
Journal of Psychopharmacology
August 2011
Susan Schenk, David N. Harper, Jennifer Do
The present study was undertaken to examine effects of self-administered MDMA on novel object exploration (NOR) memory. Self-administration was conducted during daily 2 h tests that continued until a total of 165 mg/kg was self-administered (range = 13-41 days for individual rats). Control rats were placed in the self-administration boxes during daily sessions but did not receive any drug. One...
The Open Addiction Journal
March 29, 2011
David N. Harper
5 citations
disruption to working memory function [1, 2]. This possibility was examined using a version of the 8-arm radial maze task with rats that is designed to separate working memory function from reference memory function [3]. In Experiment 1 the effects of MDMA were compared to the classic amnetic drug scopolamine (which has been shown to produce working memory deficits in the current radial arm...
The Open Addiction Journal
March 29, 2011
David N. Harper
5 citations
Both acute and chronic exposure to 3, 4-methylenedioxymethamphetamine (MDMA) is associated with impairments in a range of conditional discrimination tasks that reflect memory function, decision making and self-control [1-3]. However, the mechanism by which MDMA decreases performance in these tasks is not clear. One interpretation of such findings has been that overall stimulus control is...
The Open Addiction Journal
March 29, 2011
David N. Harper
4 citations
This study used the Drug Discrimination paradigm to assess the relative subjective experience of acutely administered 3,4-Methylenedioxymethamphetamine (MDMA) and d-amphetamine (AMPH). In this paradigm rats are required to respond on one lever if they have been given a specific drug (AMPH for one group of rats or MDMA for another group) vs an alternate lever if they have been administered...
Behavioral Neuroscience
2006
David N. Harper, Maree Hunt, Susan Schenk
26 citations
Recent evidence suggests that the disruptive effects of acute exposure to (+/-)3,4-methylene dioxymethamphetamine (MDMA) on memory performance may be the result of increased confusion between previous-trial and current-trial events. The current study tested this hypothesis by examining the effects of MDMA on performance of rats in a delayed matching-to-sample procedure when the length of the...
Hanna Squire, Jiun Youn, Bart A. Ellenbroek et al.
preprint
(±) 3,4-methylenedioxymethamphetamine (MDMA) is a recreationally abused psychostimulant that impairs memory performance. This effect is often attributed to a working memory impairment resulting from compromised serotonin systems. However, recent evidence from non-human animal experimental studies suggests that acute MDMA may indirectly impair memory performance through overstimulation of...