Bilateral infusion of 5-hydroxytryptamine (5-HT) agonists into the substantia nigra pars reticulata (SNr) of awake rats was shown to influence oral behavior. The 5-HT1A agonist (R)-8-hydroxy-2-(di-propylamino)- tetralin (8-OH-DPAT) (1.3-13 nmol on each side) produced a dose-dependent depression of vacuous chewing movements (VCMs) that lasted about 20 min. The (R)-8-OH-DPAT-induced depression of...
(+/-)3,4-Methylenedioxymethamphetamine (MDMA), a synthetic amphetamine derivative used recreationally by humans, damages brain serotonin neurons in experimental animals. In preclinical studies, serotonin reuptake inhibitors block MDMA-induced serotonin release; they also block MDMA neurotoxicity. Whether serotonin reuptake inhibitors also block MDMA's psychoactive effects in humans has not been...
The present study was undertaken to examine the drug interactions between 3,4-methylenedioxymethamphetamine (MDMA) and paroxetine or several compounds including the 3,4-methylenedioxybenzyl (piperonyl) group in mice. The time course of radioactivity in the mouse brain after i.v. administration of the tracer amount (approximately 70 ng/kg) of [3H]MDMA was altered significantly by coinjection of...
This study investigates the effects of methylenedioxymethamphetamine (MDMA) and amphetamine on monoamine release from rat superfused brain slices in both the presence and absence of vesicular stores of transmitter. MDMA caused the release of radioactivity from slices incubated with [3H]5-hydroxytryptamine, [3H]noradrenaline or [3H]dopamine with EC50 values of 1.9 mumol/l (95% confidence limits...
An advertisement in an Indian newspaper solicited accounts from people who had come close to death. Of 19 received, 7 reported no experiences, 4 reported dreamlike experiences, and 8 reported near-death experiences (NDEs). These NDEs were comparable to those reported by Raymond Moody, and included tunnels, dark spaces, and bright lights, contrary to previous reports of Indian cases. Many...
The effects of the cholinergic muscarinic agonist, oxotremorine (0.005, 0.01, 0.02 and 0.04 mg/kg), the serotonergic agonist, 5-methoxy-NN-dimethyltriptamine (5-MeODMT) (0.5, 1 and 2 mg/kg), and their combination, were investigated in C57BL/6 and DBA/2 mice using a one-trial inhibitory avoidance task, drug treatment being given immediately after the acquisition trial. Post-trial administration...
Using a standard two-lever operant paradigm, male Sprague-Dawley rats were trained to discriminate 1.5 mg/kg N-methyl-1(3,4-methylenedioxyphenyl)-2- aminopropane (MDMA) from saline using a variable-interval 15-s schedule of reinforcement for food reward. Tests of stimulus antagonism were conducted to further define the mechanism of action of MDMA as a discriminative stimulus. Low doses of the...
The stimulus effects of ibogaine were compared with those of yohimbine, an alpha 2-adrenoceptor antagonist, 2,5-dimethoxy-4-methylamphetamine (DOM), a 5-hydroxytryptamine2 (5-HT2) agonist, and lysergic acid diethylamide (LSD), a nonspecific 5-HT agonist. Rats were trained with either yohimbine (6 mg/kg), DOM (0.6 mg/kg), or LSD (0.1 mg/kg) vs. no treatment in a two-lever discrimination task....
( +_ )3,4-Methylenedioxymethamphetamine (MDMA) is a synthetic amphetamine analogue used recreationally by humans in the United States (Pcroutka 1987) and Western Europe (Anon 1992), and is thought by some to have potential utility as a psychotherapoutic adjunct (Grinspoon and Bakalar 1986). It is generally believed that MDMA acts via central monoamines, primariJy by inducing transmitter release...
Previous studies indicate that 3,4-methylenedioxymethamphetamine (MDMA) produces locomotor hyperactivity in rats by increasing the presynaptic release of serotonin (5-HT). Interactions between MDMA and 5-HT receptor antagonists suggest that the activating effects of MDMA are mediated via 5-HT1-like receptors. In order to assess the contribution of particular 5-HT receptor subtypes to the...