Mescaline and phencyclidine (PCP) are potent hallucinogenic agents affecting human and animal behavior. As their psychotropic effects remain poorly understood, further research is necessary to characterize phenotypes they evoke in various animal models. Zebrafish (Danio rerio) are rapidly emerging as a new model organism for neuroscience research. Here, we examine the effects of mescaline...
Major depressive disorder (MDD) is a common, chronic, recurrent mental illness that affects millions of individuals worldwide. Currently available antidepressants are known to affect the monoaminergic (e.g., serotonin, norepinephrine, and dopamine) systems in the brain. Accumulating evidence suggests that the glutamatergic neurotransmission via the excitatory amino acid glutamate also plays an...
Ketamine rapidly improves depressive symptoms in patients with treatment-resistant major depressive disorder (MDD) who do not respond to multiple standard antidepressants. However, it remains unknown whether ketamine is equally effective in patients with MDD who previously also did not respond to electroconvulsive therapy (ECT). This study compared 17 patients with treatment-resistant MDD who...
Interactions between glutamatergic and endocannabinoid systems may contribute to schizophrenia, dissociative states, and other psychiatric conditions. Cannabidiol (CBD), a cannabinoid-1/2 (CB1/2) receptor weak partial agonist or antagonist, may play a role in the treatment of schizophrenia. This study tested the hypothesis that CBD would attenuate the behavioral effects of the NMDA receptor...
The aim of this study was to describe sex differences in the behavioural effects of N,N-diethyllysergamide (LSD) (locomotor activity and other behavioural repertoire in the open field) and its effects on sensorimotor gating in rats (prepulse inhibition (PPI) of the acoustic startle reaction). Three groups of animals were analysed: males, oestral and pro-oestral phase females (EP females), and...
Several studies have supported the idea that ionotropic glutamate N-methyl-d-aspartate receptor (NMDA) is an important player in the etiology of psychopathologies, such as anxiety disorders and major depression. Additionally, studies have shown that ketamine induces antidepressant effects in humans as well as in rodents subjected to animal models of depression. In this context, the present...
Long-term serotonin (5-HT) neuronal loss is currently a major cause of concern associated with recreational use of the substituted amphetamine 3,4 methylenedioxymethamphetamine (MDMA; "Ecstasy"). Such loss may be problematic considering that psychiatric disorders such as depression and anxiety and responses to first line treatments for these disorders are associated with 5-HT. In this study the...
In a putative model of acute phencyclidine (PCP)-induced psychosis we evaluated effects of the drug on locomotor activity (LMA) and immediate early gene (IEG) induction in the rat using two routes of drug administration, intraperitoneal (i.p.) and subcutaneous (s.c.). Adult male rats received saline or PCP (1.0-5.0 mg/kg) either i.p or s.c. and were assessed for LMA for 60 min. At the end of...
Ketamine is a non-competitive antagonist to the phencyclidine site of N-methyl-d-aspartate (NMDA) receptor. Clinical findings point to a rapid onset of action for ketamine on the treatment of major depression. Considering that classic antidepressants may take long-lasting time to exhibit their main therapeutic effects, the present study aims to compare the behavioral effects and the BDNF...
The cognitive effects of subchronic phencyclidine administration in rats are still unsettled in the literature. Possible causes of discrepancies are different drug treatment regimens and task parameters. The current experiment tested whether variations in procedures of the delayed T-maze alternation task result in performance differences following identical PCP treatments. Sixteen rats were...
We tested the ability of 3,4-methylenedioxymethamphetamine (MDMA) to induce conditioned place preference (CPP) in dominant and subordinate OF-1 mice subjected to cohabitation and repeated sessions of agonistic confrontation, as well as in non-confronted mice. We selected doses of MDMA (2, 6, 10 mg/kg) previously reported to induce CPP in mice and we measured expression of c-Fos evoked by the...
Although preclinical studies suggest that methylone (2-methylamino-1-[3,4-methylenedioxyphenyl]propan-1-one) and 5-MeO-MIPT (5-methoxy-N-methyl,N-isopropyl tryptamine) may have psychostimulant properties, the scientific reports about the clinical effects of these agents are scant. We describe a 27-year-old male patient with substance intoxication after a single ingestion of the mixture of...
This study was designed to investigate the effect of Zen Meditation on serum nitric oxide activity (NO) and oxidative stress (lipid peroxidation). The experimental group included 20 subjects who had practiced the Zen Meditation program in Meditation Center located in Seoul, South Korea. The control group included 20 subjects who did not practice any formal stress management technique and were...
Ibogaine (IBO) is an alkaloid with putative antiaddictive properties, alleviating opiates dependence and withdrawal. The glutamate N-methyl-D-aspartate (NMDA) receptors have been implicated in the physiological basis of drug addiction; accordingly, IBO acts as a noncompetitive NMDA antagonist. The purpose of this study was to evaluate the effects of IBO on naloxone-induced withdrawal syndrome...
It has been reported that ibogaine interferes with somatic withdrawal reactions in rats chronically treated with morphine. The present experiments demonstrated that ibogaine also interferes with motivational withdrawal reactions and somatic withdrawal reactions in rats treated with morphine on only two occasions. On each of two conditioning trials, naloxone was administered 24 h following an...
1. The ability of N-ethyl (MDEA) and N-butyl (MDBA) analogues of 3,4-methylenedioxymethamphetamine (MDMA, 'Ecstasy') to induce acute behavioural changes and increases in body temperature, and to cause serotonergic neurotoxicity, was assessed in young adult male Wistar rats. The in vitro ability of MDMA analogues to evoke presynaptic monoamine release from crude rat forebrain synaptosomal...
1. 5-HT3, 5-HT2C, and 5-HT1A receptor ligands were assessed in rats trained to discriminate ibogaine from water. 2. Significant ibogaine-appropriate responding was observed following treatment with the 5-HT2C agonists MK-212 (79.6%) and mCPP (76.4%). This substitution was completely antagonized by metergoline, an agent with 5-HT2C antagonist properties. However, metergoline was ineffective...
1. A series of N-substituted tryptamines was compared with a series of beta-carbolines in rats trained to discriminate LSD (0.1 mg/kg) from saline. 2. Intermediate levels of substitution were elicited by MDMT (76.4%), DMT (77.9%), and DET (48.7%). 6-F-DET produced 41.3% LSD-appropriate responding at a dose of 6.0 mg/kg but only 4 of 8 subjects completed the test session thus precluding...
1. Previous studies of phenethylamine hallucinogenic drugs have reported that intravenous injection of DOI or similar compounds produce an inhibition of the firing rate of serotonergic dorsal raphe neurons of the rat; potentially lowering levels of 5-HT throughout the brain. 2. Direct application by iontophoresis demonstrated only weak non-specific effects, but injection into the nucleus...
1. Ibogaine, a proposed anti-addictive agent, has been found to interfere with the acquisition of a weak morphine-induced place preference. The present series of experiments determined if ibogaine would interfere with the expression of a previously established morphine (5 mg/kg) place preference. 2. A single injection of 40 mg/kg of ibogaine 24 h, 12 h or 4 h prior to the preference test...
1. The objective of this paper was to provide an understanding of methylenedioxymethamphetamine (MDMA) use. This investigation provides the subjective effects that were reported by MDMA users. 2. There were a total of (500) humans who participated in this study. 3. Using a survey device, data from users were collected. Symptomatology associated with both the consumption of MDMA and its residual...
1. Male rats were injected with either saline, diazepam, MK-801, or diazepam plus MK-801. 2. In previous work with phencyclidine (PCP), diazepam significantly reduced the increase in homovanillic acid (HVA) in olfactory tubercle and prefrontal cortex. 3. Diazepam also lowered the HVA increase following MK-801 in caudate, olfactory tubercle, and prefrontal cortex. 4. Benzodiazepine receptors may...
1. Clonidine, an alpha-2 adrenergic agonist, induced in rats a synchronization of the electrical activity of the brain (EEG) accompanied by sedation starting from the dose of 0.05 mg/kg, i.p. 2. This drug (0.05 mg/kg, i.p.) was also able to influence both the EEG and behavioural effects elicited by two "dissociative anaesthetics", PCP and KT. 3. At low and moderate doses of these two drugs,...
1. We evaluated the behavioral response of guinea pigs to hallucinogenic agents in order to characterize the response of this species to a variety of known hallucinogenic drugs. 2. The systemic injection of LSD in the guinea pig elicited a "myoclonic-like" response the frequency of which was dose-dependent. This behavior exhibited rapid tolerance which was more prominent at higher doses. 3....
1. The effects caused by the dissociative anaesthetic drugs (PCP, KT), the sigmaopiates (SKF 10.047, cyclazocine), and the mixed excitatory amino acid antagonist CCP on the electrical activity of the red nucleus in rabbits were compared with PB. 2. Ketamine (10 mg/kg, i.v.) induced the appearance of a pentobarbital-like EEG synusoidal rhythm characterized by an increase in amplitude and a...