European Journal of Pharmacology
December 1, 1986
Kurt Rasmussen, Richard A Glennon, George K. Aghajanian
50 citations
The rank order of potency for the physiological effects of three phenethylamine hallucinogens in the locus coeruleus (LC) was identical to that previously shown for their 5-HT2 binding affinity [-) DOB greater than DOM greater than ( + )DOB). The behaviorally inactive positional isomer of DOB, SL-7161, did not significantly affect LC unit activity. These results offer insight into...
European Journal of Pharmacology
August 22, 1986
D M Stone, D C Stahl, Glen R. Hanson et al.
The effects of two amphetamine-like designer drugs, 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA), on dopaminergic and serotonergic systems in the rat brain were investigated and compared to those of methamphetamine (METH). Like METH, single or multiple 10 mg/kg doses of either drug caused marked reductions in both tryptophan hydroxylase (TPH) activity and...
European Journal of Pharmacology
June 17, 1986
A J Hiltunen, Torbjörn U C Järbe
Interaction effects of cannabidiol (CBD) and cannabinol (CBN) were examined using a drug discrimination procedure in which rats had been trained to discriminate between 3 mg/kg of delta 9-tetrahydrocannabinol (delta 9-THC) and vehicle (2 ml/kg). The generalization effects of CBN to delta 9-THC were attenuated when CBN was administered together with CBD. The results were time- and dose-dependent.
European Journal of Pharmacology
April 1, 1986
We compared the effects of the hallucinogens 2,5-dimethoxy-4-methylamphetamine (DOM), mescaline and the simulant D-amphetamine, applied by microiontophoresis to rat dorsal raphe (DR) units. DR neuron firing rate was relatively insensitive to DOM and unaffected by mescaline, but was clearly inhibited by D-amphetamine. Intravenous DOM usually inhibited, but this effect was correlated with blood...
European Journal of Pharmacology
October 1, 1985
Mark D. Tricklebank, Christian Forler, Derek N. Middlemiss et al.
141 citations
The 5-HT receptor subtypes involved in the mediation of reciprocal forepaw treading and the flat body posture induced by the central 5-HT receptor agonist, 5-methoxy-N,N-dimethyltryptamine (5-MeODMT), were examined in intact rats and in rats depleted of monoamines with reserpine. Forepaw treading in non-reserpinised rats was antagonised by the 5-HT2 receptor antagonist, ketanserin, only at...
European Journal of Pharmacology
January 15, 1985
Michael E. Trulson, G F Keltch
18 citations
Chronic administration of 5-methoxy-N,N-dimethyltryptamine (5-MeODMT, 2 mg/kg i.p., every 30 min for 4 h) produced a dramatic tolerance to the behavioral effects of the drug in rats. The ED50 for the syndrome-inducing effects of the drug was increased from 1.3 to 2.4 mg/kg, and the mean duration of the syndrome was decreased from 14.9 to 1.2 min after this treatment. This tolerance effect...
European Journal of Pharmacology
October 1, 1984
M D Hynes, D L Hymson
The discriminative stimulus properties of nitrous oxide, an analgesic and anesthetic gas, were evaluated in rats trained to discriminate the effects of morphine or ethylketocyclazocine. Administration of nitrous oxide in concentrations as high as 80 percent did not produce generalization to the discriminative cue produced by morphine. Nitrous oxide did, however, generalize in a...
European Journal of Pharmacology
September 3, 1984
A P Nisbet, C A Marsden
29 citations
Chemical lesioning of the 5-hydroxytryptamine neurones in the brain with 5,7-dihydroxytryptamine (200 micrograms i.c.v., 14 or 21 days previously) resulted in an enhanced behavioral response following administration of the 5-hydroxytryptamine receptor agonist 5-methoxy-N,N-dimethyltryptamine (2.5 mg/kg). The increase in the behavioural response showed a positive correlation with the decrease in...
European Journal of Pharmacology
July 1, 1984
F Gonzalez-Lima, W L Stiehl, R Medina
The objective was to determine the behavioral effects and duration of action of bromocriptine (BC) doses from 6 to 60 mg/kg i.p. Cats were housed in large outdoors cages designed for prolonged observation using an ethological approach. Baseline behavior was measured after a 3 month period of habituation. The frequency of 12 behaviors was then scored continuously over 12 h following BC...
European Journal of Pharmacology
June 15, 1984
M Shannon, G Battaglia, Richard A Glennon et al.
The affinities of a series of 1-(2,5-dimethoxyphenyl)-2-aminopropane (2,5-DMA) derivatives, most of which are hallucinogenic in man, and several related agents were determined for rat cortical serotonin (5-HT) binding sites. Competition assays were performed in which these agents were competed for the 5-HT2 binding of [3H]ketanserin, or the 5-HT1 binding of [3H]LSD (in the presence of...
European Journal of Pharmacology
May 18, 1984
J Heym, K Rasmussen, B L Jacobs
Although central serotonergic systems appear to be linked importantly to the mechanism of action of a variety of hallucinogenic drugs, the nature of this interaction has remained unclear. In the present study, the question of whether the critical link is presynaptic or postsynaptic was examined in cats. Behaviorally inactive doses (1.0 mg/kg) of the serotonin receptor antagonists mianserin,...
European Journal of Pharmacology
1984
David P. Geaney, Michael Schächter, Jonathan Elliot et al.
90 citations
Specific binding of [3H]lysergic acid diethylamide (LSD) to human platelet membranes, as defined by 300 nM spiperone, was saturable over the concentration range of 0.25-2.5 nM [3H]LSD. At 0.5 nM [3H]LSD the half-time for association at 37 degrees C was 56 min, half-time for dissociation was 173 min, and the kinetically derived affinity was 0.24 nM. In 19 control subjects equilibrium binding...
European Journal of Pharmacology
December 1, 1983
Michael E. Trulson, Terriann Crisp, Leslie J. Henderson
21 citations
The characteristic behavioral effects of mescaline in cats were nearly completely blocked by pretreatment with low doses of either a specific serotonin antagonist (methysergide) or a dopamine specific antagonist (haloperidol). These blocking effects were not due to non-specific actions, since methysergide did not block the behavioral effects of apomorphine, and haloperidol did not block the...
European Journal of Pharmacology
November 25, 1983
R A Shephard, P L Broadhurst
20 citations
The effects of 5-MeODMT (2.5 mg/kg), diazepam (1 mg/kg), methysergide and the stereoisomers of propranolol (6 mg/kg) on hyponeophagia were studied in both sexes of the Roman strains of rats, selectively bred for acquisition of a two-way conditioned avoidance response. Diazepam, methysergide and 1-propranolol increased feeding in a novel environment whilst 5-MeODMT decreased it and d-propranolol...
European Journal of Pharmacology
September 1, 1983
In superfusion experiments with a crude synaptosomal fraction from the nucleus accumbens of rats, lysergic acid diethylamide, mescaline and N,N-dimethyltryptamine (representing different chemical classes of psychotomimetics) produced a concentration-related inhibition of K+-evoked [3H]dopamine release whereas spontaneous release remained unchanged. The nonpsychotomimetic ergoline lisuride...
European Journal of Pharmacology
July 1, 1983
Rats trained to discriminate 1.0 mg/kg of 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM) from saline in a two-lever operant choice task were administered doses of mescaline, LSD, 5-methoxy-N,N-dimethyltryptamine (5-OMe DMT), quipazine, TFMPP and RU-24969. The DOM-stimulus generalized to the three hallucinogenic agents and to quipazine, but not to the purported serotonin agonists TFMPP or...
European Journal of Pharmacology
June 3, 1983
Barry L. Jacobs, J Heym, K Rasmussen
25 citations
Significant negative correlations were obtained between the spontaneous discharge rate during waking and the neural response to systemic injections of either 5-MeODMT or LSD for serotonergic neurons in the dorsal raphe nucleus, nucleus centralis superior, and nucleus raphe pallidus of unanesthetized and unrestrained cats. These data are discussed in terms of an hypothesis which accounts for...
European Journal of Pharmacology
June 3, 1983
O G Berge, D Chacho, K Hole
20 citations
5-Methoxy-N,N-dimethyltryptamine (5-MeODMT) in concentrations of 0.5-500 microM produced a significant inhibition of [14C]5-hydroxytryptamine [14C]5-HT) uptake in striatal, hippocampal and hypothalamic crude synaptosomes from rat brain. Higher concentrations of 5-MeODMT (10 microM) also inhibited the uptake of [3H]dopamine [3H]DA) and induced the release of [14C]5-HT and [3H]DA from preloaded...
European Journal of Pharmacology
January 21, 1983
Richard A Glennon, R Young, John M. Jacyno et al.
Stimulus generalization studies were conducted using rats trained to discriminate 1.0 mg/kg of the phenalkylamine hallucinogen 1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane (DOM) from saline in a two-lever operant procedure. The results suggest that certain indolealkylamine hallucinogens, including LSD and several alpha-methyltryptamine, N,N-dialkyltryptamine and beta-carboline derivatives,...
European Journal of Pharmacology
July 30, 1982
J Heym, G F Steinfels, Barry L. Jacobs
21 citations
A comparison was made of the effects of 5-MeoDMT or LSD on serotonergic unit activity in the dorsal raphe nucleus (DRN) and nucleus raphe pallidus (NRP) of freely moving cats. NRP neurons were substantially less responsive than DRN neurons to both drugs. NRP neurons were unresponsive to behaviorally effective low doses of these drugs whereas the activity of DRN neurons was strongly depressed....
European Journal of Pharmacology
February 26, 1982
C P Vandermaelen, George K. Aghajanian
37 citations
Intracellular recordings were made from facial motoneurons of anesthetized rats during systemic administration of 5-methoxy-N,-N-dimethyltryptamine (5-MeODMT) and p-chloroamphetamine (PCA), drugs which elicit the behavioral serotonin syndrome. Both drugs caused a slow depolarization, increased input resistance, and increased excitability of facial motoneurons. These changes are identical to...
European Journal of Pharmacology
December 17, 1981
Richard A Glennon, John A. Rosecrans, R Young
21 citations
Rats were trained to discriminate injections of 5-methoxy-N,N-dimethyltryptamine (5-OMe DMT, 3.0 mg/kg) a hallucinogenic agent for which a serotonergic mechanism has been implicated, from saline in a two-lever drug discrimination task. After reliable levels of accuracy (greater than or equal to 85%) were attained, the ability of the 5-OMe DMT cue to generalize to 36 substituted...
European Journal of Pharmacology
November 1, 1981
Heidrun Fink, Wolfgang Oelssner
44 citations
Microinjections of LSD (0.05 microgram), mescaline (0.5 microgram) and serotonin (10 microgram) into the medial raphe nucleus of rats resulted in a strong potentiation of apomorphine (1 mg/kg i.p.)-induced hypermotility. The potentiating effect of LSD or serotonin was suppressed by simultaneous injections of methysergide (0.05 microgram) or cyproheptadine (0.05 microgram) into the medial raphe...
European Journal of Pharmacology
October 15, 1979
Miljana Simonovic, Herbert Y. Meltzer
11 citations
Repeated administration of 5-methoxy-N,N-dimethyltryptamine (5MeODMT, 5 mg/kg, a serotonin agonist, every 3 h for a total of 4 injections) potentiated its prolactin (PRL)-releasing effect and that of two other serotonin agonists, quipazine and N,N-dimethyltryptamine. This pretreatment schedule had no effect on PRL response to anti-dopaminergic drugs. The onset of enhanced PRL response to...
European Journal of Pharmacology
October 15, 1979
Françis C. Colpaert, C J Niemegeers, P A Janssen
Using a food-reinforced two-lever operant method, rats (n = 9) were trained to discriminate 0.16 mg/kg LSD from saline. Tests for stimulus generalization in rats so trained indicated that the purported 5-HT antagonists cyproheptadine (1.25 and 10 mg/kg), methysergide (0.16 to 10 mg/kg) and mianserin (2.5 to 40 mg/kg) produced partial generalization with LSD. The hallucinogens mescaline (5 to 40...