MDMA and memory: the acute and chronic effects of MDMA in pigeons performing under a delayed-matching-to-sample procedure

Abstract

The purpose of the present study was to examine the acute and chronic effects of (+/-)3,4-methylenedioxy-methamphetamine (MDMA) in pigeons responding under a delayed-matching-to-sample procedure with 0-, 3-, and 6-s delays. In the absence of drug, accuracy (percent correct responses) was inversely related to delay length. When administered pre-chronically, MDMA (0.32-5.6 mg/kg) generally decreased accuracy and response rates at doses of 3.2 mg/kg and above. Although humans report a distinct "hangover" when exposure to MDMA ends, performance of pigeons in the present study did not deteriorate when the chronic regimen ended, indicating an absence of behavioral dependence on the drug. Tolerance developed following chronic exposure to 3.2 mg/kg. In general, greater tolerance occurred at the 0-s delay than at longer delays. Although MDMA is reported to have neurotoxic effects, it does not inevitably produce long-lasting or cumulative behavioral impairment.

Abnormal ACTH and prolactin responses to fenfluramine in rats exposed to single and multiple doses of MDMA

“…The neuroendocrine response to 8-OH-DPAT, a 5-HT 1A agonist, also was found to be abnormal 2 weeks after a single dose of MDMA (Poland 1990). In contrast, persistent e¤ects of MDMA on memory have not been found (LeSage et al 1993;Ricaurte et al 1993;Robinson et al 1993). To our knowledge, no functional abnormalities have been reported beyond 2 weeks.…”

“…As manifested by decreased 5-HT concentrations and 5-HT reuptake sites, administration of a single dose of MDMA can disrupt 5-HT systems for weeks (Commins et al 1987), whereas multiple doses are a¤ective for months (De Souza and Battaglia 1989). Despite considerable data on the neurochemical e¤ects of MDMA, it remains unclear as to whether functional alterations are linked to the neurochemical changes (Nencini et al 1988;Poland 1990;Winslow and Insel 1990;Sharkey et al 1991;Rezvani et al 1992;LeSage et al 1993;Ricaurte et al 1993;Robinson et al 1993;Romano and Harvey 1994;McNamara et al 1995). Because the central nervous system (CNS) is the predominate regulator of neuroendocrine function (Tuomisto and Männistö 1985), with pituitary ACTH and prolactin secretion strongly inßuenced by 5-HT pathways in the brain (Van de Kar 1991;Fuller 1992), an abnormal response of these hormones to 5-HT agonist administration might serve as a potential functional marker of MDMA neurotoxicity.…”

Behavioural analysis of the acute and chronic effects of MDMA treatment in the rat

“…Few studies have attempted to relate the chronic consequences of MDMA exposure to cognitive impairment. Pigeons exhibit a decrease in accuracy and response rates in a delayed non-matching to sample task immediately following MDMA treatment, but show no deficit in performance following chronic exposure (LeSage et al 1993). The choice accuracy of rats in a T-maze following chronic exposure of MDMA was unaffected .…”

Attenuation of the disruptive effects of (+/-)3,4-methylenedioxymethamphetamine and cocaine on delayed matching-to-sample performance with D1 versus D2 antagonists

“…A number of studies have demonstrated that acute exposure to the stimulant (+/‐)3,4‐methylenedioxymethamphetamine (MDMA) will produce a disruption to recognition or working memory‐task performance in humans (Parrott & Lasky 1998), pigeons (LeSage, Clark & Poling 1993), monkeys (Taffe et al . 2001) and rats (Harper et al .…”