Abstract
Several reports have speculated that the tryptamine-derived drug alpha-ethyltryptamine (AET) may have effects similar to those of the amphetamine-derived drug 3,4-methylenedioxymethamphetamine (MDMA). Indeed, the US Drug Enforcement Administration has recently placed AET on the Schedule I list because of its putative similarity to MDMA. The Behavioral Pattern Monitor, which quantifies locomotor and investigatory responses of rats, was used to characterize the effects of AET in a paradigm that distinguishes between the effects of traditional hallucinogens, amphetamine-like stimulants, and MDMA-like drugs. First, a dose-response study revealed that all doses of AET tested (5, 10, 20 mg/kg) significantly increased locomotor activity. Locomotor hyperactivity is produced by MDMA or amphetamine-like stimulants, but not by classical hallucinogens, such as LSD or mescaline. Additionally, AET significantly decreased measures of investigatory behavior. Similar decreases occur with MDMA or hallucinogen administration, but not with amphetamine-like stimulant administration. Second, as with MDMA, the locomotor hyperactivity induced by AET was attenuated by pretreatment (10 mg/kg) with the serotonin reuptake inhibitor fluoxetine. Thus, AET, a tryptamine-derived drug, appears to produce an MDMA-like profile of behavioral changes by virtue of releasing presynaptic serotonin.
References
Adams LM, Geyer MA (1985) A proposed animal model for hallucinogens based on LSD's effects on patterns of exploration in rats. Behav Neurosci 99:881–900
Baker GB, Hiob LE, Dewhurst WG (1980) Effects of monoamine oxidase inhibitors on release of dopamine and 5-hydroxytryptamine from rat striatum in vitro. Cell Mol Biol 26:182–186
Callaway CW, Wing LL, Geyer MA (1990) Serotonin release contributes to the locomotor stimulant effects of 3,4-methylenedioxymethamphetamine in rats. J Pharmacol Exp Ther 254:456–464
Callaway CW, Johnson MP, Gold LH, Nichols DE, Geyer MA (1991) Amphetamine derivatives induce locomotor hyperactivity by acting as indirect serotonin agonists. Psychopharmacology 104:293–301
Daldrup T, Heller C, Matthiesen U, Honus S, Bresges A, Haarhof K (1986) Etryptamine, a new designer drug with a fatal effect. Z Rechtsmed 97:61–68
Federal Register (1993) 58(47): 13533, March 12
Geyer MA, Krebs KM (1993) Serotonin receptor involvement in an animal model of the acute effects of hallucinogens. In: Lin G (ed) Hallucinogens: an update. NIDA Research Monograph Series, National Institute on Drug Abuse, Rockville, Maryland (in press)
Gold LH, Koob GF, Geyer MA (1988) Stimulant and hallucinogenic behavioral profiles of 3,4-methylenedioxymethamphetamine andN-ethyl-3,4-methylenedioxymethamphetamine in rats. J Pharmacol Exp Ther 247:547–555
Grieg ME, Walk RA, Gibbons AJ (1959) The effect of three tryptamine derivatives on serotonin metabolism in vitro and in vivo. J Pharmacol Exp Ther 127:110–115
Huang X, Johnson MP, Nichols DE (1991) Reduction in brain serotonin markers by alpha-ethyltryptamine (Monase). Eur J Pharmacol 200:187–190
Krebs KM, Geyer MA (1993) Cross-tolerance studies of serotonin receptors involved in behavioral effects of LSD in rats. Psychopharmacology (in press)
Renyi L (1986) The effects of monoamine oxidase inhibitors on the ejaculatory response induced by 5-methoxy-N,N-dimethyl-tryptamine in the rat. Br J Pharmacol 88:827–835
Renyi L, Ross SB (1985) Effects of amiflamine and related compounds on the accumulation of biogenic monoamines in rat brain slices in vitro and ex vivo in relation to their behavioural effects. Acta Pharmacol Toxicol 56:416–426
Renyi L, Archer T, Minor BG, Tandberg B, Fredriksson A, Ross SB (1986) The inhibition of the cage-leaving response — a model for studies of the serotonergic neurotransmission in the rat. J Neural Transm 65:193–210
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Krebs, K.M., Geyer, M.A. Behavioral characterization of alpha-ethyltryptamine, a tryptamine derivative with MDMA-like properties in rats. Psychopharmacology 113, 284–287 (1993). https://doi.org/10.1007/BF02245712
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF02245712