The acute effect in rats of 3,4-methylenedioxyethamphetamine (MDEA, "eve") on body temperature and long term degeneration of 5-HT neurones in brain: a comparison with MDMA ("ecstasy")

Beyond ecstasy: Alternative entactogens to 3,4-methylenedioxymethamphetamine with potential applications in psychotherapy

The last two decades have seen a revival of interest in the entactogen 3,4-methylenedioxy-N-methylamphetamine (MDMA) as an adjunct to psychotherapy, particularly for the treatment of post-traumatic stress disorder. While clinical results are highly promising, and MDMA is expected to be approved as a treatment in the near future, it is currently the only compound in its class of action that is being actively investigated as a medicine. This lack of alternatives to MDMA may prove detrimental to patients who do not respond well to the particular mechanism of action of MDMA or whose treatment calls for a modification of MDMA's effects. For instance, patients with existing cardiovascular conditions or with a prolonged history of stimulant drug use may not fit into the current model of MDMA-assisted psychotherapy, and could benefit from alternative drugs. This review examines the existing literature on a host of entactogenic drugs, which may prove to be useful alternatives in the future, paying particularly close attention to any neurotoxic risks, neuropharmacological mechanism of action and entactogenic commonalities with MDMA. The substances examined derive from the 1,3-benzodioxole, cathinone, benzofuran, aminoindane, indole and amphetamine classes. Several compounds from these classes are identified as potential alternatives to MDMA.

Downregulation of the Vitamin D Receptor Regulated Gene Set in the Hippocampus After MDMA Treatment

The active ingredient of ecstasy, ±3,4-methylenedioxymethamphetamine (MDMA), in addition to its initial reinforcing effects, induces selective and non-selective brain damage. Evidences suggest that the hippocampus (HC), a central region for cognition, may be especially vulnerable to impairments on the long-run, nevertheless, transcription factors that may precede and regulate such chronic changes remained uninvestigated in this region. In the current study, we used gene-set enrichment analysis (GSEA) to reveal possible transcription factor candidates responsible for enhanced vulnerability of HC after MDMA administration. Dark Agouti rats were intraperitoneally injected with saline or 15 mg/kg MDMA. Three weeks later HC gene expression was measured by Illumina whole-genome beadarrays and GSEA was performed with MSigDB transcription factor sets. The number of significantly altered genes on the genome level (significance < 0.001) in up/downregulated sets was also counted. MDMA upregulated one, and downregulated 13 gene sets in the HC of rats, compared to controls, including Pax4, Pitx2, FoxJ2, FoxO1, Oct1, Sp3, AP3, FoxO4, and vitamin D receptor (VDR)-regulated sets (q-value <0.05). VDR-regulated set contained the second highest number of significantly altered genes, including among others, Camk2n2, Gria3, and Grin2a. Most identified transcription factors are implicated in the response to ischemia confirming that serious hypoxia/ischemia occurs in the HC after MDMA administration, which may contribute to the selective vulnerability of this brain region. Moreover, our results also raise the possibility that vitamin D supplementation, in addition to the commonly used antioxidants, could be a potential alternative method to attenuate MDMA-induced chronic hippocampal impairments.

Pharmacology of MDMA- and Amphetamine-Like New Psychoactive Substances

New psychoactive substances (NPS) with amphetamine-, aminoindan-, and benzofuran basic chemical structures have recently emerged for recreational drug use. Detailed information about their psychotropic effects and health risks is often limited. At the same time, it emerged that the pharmacological profiles of these NPS resemble those of amphetamine or 3,4-methylenedioxymethamphetamine (MDMA). Amphetamine-like NPS induce psychostimulation and euphoria mediated predominantly by norepinephrine (NE) and dopamine (DA) transporter (NET and DAT) inhibition and transporter-mediated release of NE and DA, thus showing a more catecholamine-selective profile. MDMA-like NPS frequently induce well-being, empathy, and prosocial effects and have only moderate psychostimulant properties. These MDMA-like substances primarily act by inhibiting the serotonin (5-HT) transporter (SERT) and NET, also inducing 5-HT and NE release. Monoamine receptor interactions vary considerably among amphetamine- and MDMA-like NPS. Clinically, amphetamine- and MDMA-like NPS can induce sympathomimetic toxicity. The aim of this chapter is to review the state of knowledge regarding these substances with a focus on the description of the in vitro pharmacology of selected amphetamine- and MDMA-like NPS. In addition, it is aimed to provide links between pharmacological profiles and in vivo effects and toxicity, which leads to the conclusion that abuse liability for amphetamine-like NPS may be higher than for MDMA-like NPS, but that the risk for developing the life-threatening serotonin syndrome may be increased for MDMA-like NPS.

Psychiatric profiles of mothers who take Ecstasy/MDMA during pregnancy: reduced depression 1 year after giving birth and quitting Ecstasy

BACKGROUND

The recreational drug MDMA (3,4-methylenedioxymethamphetamine) or 'Ecstasy' is associated with heightened psychiatric distress and feelings of depression. The Drugs and Infancy Study (DAISY) monitored the psychiatric symptom profiles of mothers who used Ecstasy/MDMA while pregnant, and followed them over the first year post-partum.

METHODS

We compared 28 young women whom took MDMA during their pregnancy with a polydrug control group of 68 women who took other psychoactive drugs while pregnant. The Brief Symptom Inventory (BSI) was completed for several periods: The first trimester of pregnancy; and 1, 4 and 12 months after childbirth. Recreational drug use was monitored at each time point.

RESULTS

During the first trimester of pregnancy, MDMA-using mothers reported higher depression scores than the polydrug controls. At 1 year after childbirth, their BSI depression scores were significantly lower, now closer to the control group values. At the same time point, their self-reported use of MDMA became nearly zero, in contrast to their continued use of Cannabis/marijuana, nicotine and alcohol. We found significant symptom reductions in those with BSI obsessive-compulsive and interpersonal sensitivity, following Ecstasy/MDMA cessation.

CONCLUSIONS

The findings from this unique prospective study of young recreational drug-using mothers are consistent with previous reports of improved psychiatric health after quitting MDMA.

Decrease in REM latency and changes in sleep quality parallel serotonergic damage and recovery after MDMA: a longitudinal study over 180 days

The recreational drug ecstasy [3,4-methylenedioxymethamphetamine (MDMA)], has been found to selectively damage brain serotonin neurons in experimental animals, and probably in human MDMA users, but detailed morphometric analyses and parallel functional measures during damage and recovery are missing. Since there is evidence that serotonin regulates sleep, we have compared serotonergic markers parallel with detailed analysis of sleep patterns at three time-points within 180 d after a single dose of 15 mg/kg MDMA in male Dark Agouti rats. At 7 d and 21 d after MDMA treatment, significant(30-40%), widespread reductions in serotonin transporter (5-HTT) density were detected in the cerebral cortex, hippocampus, most parts of the hypothalamus, and some of the brainstem nuclei. With the exception of the hippocampus, general recovery was observed in the brain 180 d after treatment. Transient increases followed by decreases were detected in 5-HTT mRNA expression of dorsal and median raphe nuclei at 7 d and 21 d after the treatment. Significant reductions in rapid eye movement (REM) sleep latency, increases in delta power spectra in non-rapid eye movement sleep and increased fragmentation of sleep were also detected, but all these alterations disappeared by the 180th day. The present data provide evidence for long-term, albeit, except for the hippocampus, transient changes in the terminal and cellular regions of the serotonergic system after this drug. Reduced REM latency and increased sleep fragmentation are the most characteristic alterations of sleep consistently described in depression using EEG sleep polygraphy.

Enhanced tau phosphorylation in the hippocampus of mice treated with 3,4-methylenedioxymethamphetamine ("Ecstasy")

3,4-Methylenedioxymethamphetamine (MDMA) ("Ecstasy") produces neurotoxic effects, which result into an impairment of learning and memory and other neurological dysfunctions. We examined whether MDMA induces increases in tau protein phosphorylation, which are typically associated with Alzheimer's disease and other chronic neurodegenerative disorders. We injected mice with MDMA at cumulative doses of 10-50 mg/kg intraperitoneally, which are approximately equivalent to doses generally consumed by humans. MDMA enhanced the formation of reactive oxygen species and induced reactive gliosis in the hippocampus, without histological evidence of neuronal loss. An acute or 6 d treatment with MDMA increased tau protein phosphorylation in the hippocampus, revealed by both anti-phospho(Ser(404))-tau and paired helical filament-1 antibodies. This increase was restricted to the CA2/CA3 subfields and lasted 1 and 7 d after acute and repeated MDMA treatment, respectively. Tau protein was phosphorylated as a result of two nonredundant mechanisms: (1) inhibition of the canonical Wnt (wingless-type MMTV integration site family) pathway, with ensuing activation of glycogen synthase kinase-3beta; and (2) activation of type-5 cyclin-dependent kinase (Cdk5). MDMA induced the expression of the Wnt antagonist, Dickkopf-1, and the expression of the Cdk5-activating protein, p25. In addition, the increase in tau phosphorylation was attenuated by strategies that rescued the Wnt pathway or inhibited Cdk5. Finally, an impairment in hippocampus-dependent spatial learning was induced by doses of MDMA that increased tau phosphorylation, although the impairment outlasted this biochemical event. We conclude that tau hyperphosphorylation in the hippocampus may contribute to the impairment of learning and memory associated with MDMA abuse.

Serotonin mediates rapid changes of striatal glucose and lactate metabolism after systemic 3,4-methylenedioxymethamphetamine (MDMA, “Ecstasy”) administration in awake rats

The pathway for selective serotonergic toxicity of 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy") is poorly understood, but has been linked to hyperthermia and disturbed energy metabolism. We investigated the dose-dependency and time-course of MDMA-induced perturbations of cerebral glucose metabolism in freely moving rats using rapid sampling microdialysis (every minute) coupled to flow-injection analysis (FIA) with biosensors for glucose and lactate. Blood samples for analysis of glucose and lactate were taken at 30-45 min intervals before and after drug dosing and body temperature was monitored by telemetry. A single dose of MDMA (2-10-20 mg/kg i.v.) evoked a transient increase of interstitial glucose concentrations in striatum (139-223%) with rapid onset and of less than 2h duration, a concomitant but more prolonged lactate increase (>187%) at the highest MDMA dose and no significant depletions of striatal serotonin. Blood glucose and lactate levels were also transiently elevated (163 and 135%) at the highest MDMA doses. The blood glucose rises were significantly related to brain glucose and brain lactate changes. The metabolic perturbations in striatum and the hyperthermic response (+1.1 degrees C) following systemic MDMA treatment were entirely blocked in p-chlorophenylalanine pre-treated rats, indicating that these effects are mediated by endogenous serotonin.

Effects of MDMA, MDA and MDEA on blood pressure, heart rate, locomotor activity and body temperature in the rat involve alpha-adrenoceptors

The effects of injection of 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA) and N-ethyl-3,4-methylenedioxyamphetamine (MDEA) (all 20 mg kg(-1)) on blood pressure, heart rate, core body temperature and locomotor activity in conscious rats were investigated using radiotelemetry. MDMA and MDA produced a prolonged increase in both systolic and diastolic pressures, with MDA causing the most marked rise. MDEA produced a transient but nonsignificant fall in diastolic pressure. The pressor response produced by MDA was accompanied by bradycardia. All three amphetamine derivatives caused an initial hypothermic response; however, MDA also produced a subsequent hyperthermia, and the speed of recovery from hypothermia was MDA>MDMA>MDEA. The alpha2A-adrenoceptor antagonist 2-((4,5-dihydro-1H-imidazol-2-yl)methyl)-2,3-dihydro-1-methyl-1H-isoindole (BRL 44408) (1 mg kg(-1)) prolonged the hypothermic response to MDMA. Only MDA induced locomotor activity when given alone, but in the presence of BRL 44408, MDMA produced increased locomotor activity. The order of potency for producing isometric contractions of rat aorta (alpha1D) and vas deferens (alpha1A) was MDA>MDMA>MDEA, with MDEA acting as an alpha1-adrenoceptor antagonist with a pK(B) of 4.79+/-0.12 (n = 4) in aorta. The order of potency for prejunctional inhibition of stimulation-evoked contractions in rat vas deferens (alpha2A-adrenoceptor mediated) was MDA>MDMA>MDEA. Blood pressure actions of the three amphetamine derivatives may be at least partly due to alpha1-adrenoceptor agonism or antagonism. The reversal of the hypothermic actions are at least partly due to alpha2A-adrenoceptor agonism since the hypothermic response was more prolonged with MDEA which exhibits low alpha2A-adrenoceptor potency, and effects of MDMA after alpha2A-adrenoceptor antagonism were similar to those of MDEA.

Synthesis of Fluoro Analogues of 3,4-(Methylenedioxy)amphetamine (MDA) and Its Derivatives

The role of the metabolism of the entactogen 3,4-(methylenedioxy)methamphetamine (MDMA; 1b) in neurotoxic or psychopharmacologic action is widely discussed, but not yet fully understood. To prompt further investigation into the role of MDMA metabolism, six new 3,4-(difluoromethylenedioxy) analogues of MDMA (1b) were prepared and characterized. Although electronically very different, the fluoro analogues 3-5 should be sterically very similar to the non-fluorinated parent compounds. The F-atoms may prevent the formation of toxic metabolites produced via a radical pathway (Scheme 1). Different theories regarding MDMA-induced neurotoxicity are briefly reviewed and discussed. The novel compounds 3-5 may help to verify the hypothesis that MDMA-induced neurotoxicity is the result of the formation of metabolites lacking the methylenedioxy bridge.

Initial deficit and recovery of function after MDMA preexposure in rats

RATIONALE

3,4-methylenedioxymethamphetamine (MDMA) exposure was reported to result in deficits in serotonergic neurotransmission with concomitant behavioral suppression and tolerance to MDMA. Some data have also suggested that the neurochemical deficits recover over time, raising the question as to whether behavioral suppression would show a similar recovery.

OBJECTIVES

The possibility of recovery of behavioral deficits was examined in the present study. Rats were administered an MDMA pretreatment regimen that was shown to produce numerous serotonergic deficits and behavioral suppression 2 weeks thereafter. The full expression of MDMA-produced hyperactivity was dependent upon serotonergic integrity, therefore, the present study aimed to determine whether MDMA pretreated rats were tolerant to MDMA 2 weeks after exposure. Further, because serotonergic deficits have shown recovery over time, similar behavioral tests were conducted at a later time point to determine whether functional recovery was evident.

METHODS

MDMA-produced hyperactivity was measured at different withdrawal periods (2 and 12 weeks) to determine initial effects and the possibility of recovery of function.

RESULTS

In saline-pretreated control rats, +/-MDMA (0.0-10.0 mg/kg) produced a dose-dependent increase in locomotor activity. Rats that had received prior exposure to MDMA (4 x 10 mg/kg MDMA injections administered at 2 h intervals) demonstrated tolerance when the activity was measured 2 weeks after pretreatment. For these rats, there was a downward shift in the dose-effect curve for MDMA-produced hyperactivity. MDMA-produced hyperactivity in rats that were tested 12 weeks after pretreatment was, however, comparable to controls, suggesting recovery of function.

CONCLUSION

These data are consistent with the idea that high dose MDMA exposure produces neuroadaptations that exhibit recovery with extended abstinence from the drug.

Amphetamine toxicity in the emergency department

XTC and other amphetamines are considered to be safe by the majority of partying young people who are unaware of (or unwilling to know about) the acute and chronic toxicity of these substances, and these drugs are widespread, illicit stimulants. In this article, we describe four cases of severe acute toxicity due to recreational use of amphetamines 3,4-methylene-dioxymethamphetamine, 3,4-methylenedioxyethylamphetamine, 3,4-methylenedioxyamphetamine, 4-methylthioamphetamine or p-methoxyamphetamine, with emphasis on the presenting symptoms and acute treatment in the emergency department.

Functional MRI study of working memory in MDMA users

RATIONALE

Methylene-dioxymethamphetamine (MDMA) is known to cause degeneration of serotonin nerve terminals after acute doses in animals. Similarly, behavioral studies in human MDMA users regularly find abnormalities in memory, mood, and impulse control. However, studies of brain function using brain imaging in MDMA users have been less consistent.

OBJECTIVES

The purpose of this study was to determine, using functional magnetic resonance imaging (fMRI), whether individuals with a self-reported history of MDMA use would differ from non-MDMA using controls on activation while performing a working memory task.

METHODS

Fifteen MDMA using subjects and 19 non-MDMA using controls underwent fMRI scanning while performing the immediate and delayed memory task (IMT/DMT). The study was based on a block design in which the delayed memory task (DMT) alternated with the immediate memory task (IMT), which served as a control condition. FMRI scans were acquired on a 1.5 T scanner, using a gradient echo echoplanar pulse sequence.

RESULTS

Random effects SPM99 analysis showed significantly greater activation (whole volume corrected cluster P<0.05) during the DMT relative to the IMT in the MDMA subjects compared with the control subjects in the medial superior frontal gyrus, in the thalamus extending into putamen, and in the hippocampus.

CONCLUSIONS

Although these effects could be due to other drugs used by MDMA users, these results are consistent with behavioral problems that are associated with MDMA use, and with animal studies on the effects of MDMA on brain function.

Combined toxicity of prenatal bacterial endotoxin exposure and postnatal 6-hydroxydopamine in the adult rat midbrain

We previously reported that injection of the Gram (-) bacteriotoxin, lipopolysaccharide (LPS), into gravid females at embryonic day 10.5 led to the birth of animals with fewer than normal dopamine (DA) neurons when assessed at postnatal days (P) 10 and 21. To determine if these changes continued into adulthood, we have now assessed animals at P120. As part of the previous studies, we also observed that the pro-inflammatory cytokine tumor necrosis factor alpha (TNFalpha) was elevated in the striatum, suggesting that these animals would be more susceptible to subsequent DA neurotoxin exposure. In order to test this hypothesis, we injected (at P99) 6-hydroxydopamine (6OHDA) or saline into animals exposed to LPS or saline prenatally. The results showed that animals exposed to prenatal LPS or postnatal 6OHDA alone had 33% and 46%, respectively, fewer DA neurons than controls, while the two toxins combined produced a less than additive 62% loss. Alterations in striatal DA were similar to, and significantly correlated with (r(2)=0.833) the DA cell losses. Prenatal LPS produced a 31% increase in striatal TNFalpha, and combined exposure with 6OHDA led to an 82% increase. We conclude that prenatal exposure to LPS produces a long-lived THir cell loss that is accompanied by an inflammatory state that leads to further DA neuron loss following subsequent neurotoxin exposure. The results suggest that individuals exposed to LPS prenatally, as might occur had their mother had bacterial vaginosis, would be at increased risk for Parkinson's disease.

Baclofen prevents MDMA-induced rise in core body temperature in rats

A number of deaths have been attributed to severe hyperthermia resulting from the ingestion of 3,4-methylenedioxymethamphetamine (MDMA). The mechanisms underlying these events are unclear. In an attempt to further advance our understanding of these mechanism the present study investigated the effects of the selective GABA(A) agonist muscimol and the GABA(B) agonist baclofen on MDMA-induced responses in the rat. Baclofen at 1 and 3 mg/kg and muscimol at 0.3 and 1 mg/kg administered alone had no effect on heart rate, core body temperature or spontaneous locomotor activity as measured by radiotelemetry. MDMA at 15 mg/kg produced a significant increase in heart rate, body temperature and locomotor activity (P < 0.005) which were unaffected by prior treatment with muscimol. In contrast, prior treatment with baclofen (3 mg/kg) resulted in MDMA causing a sustained lowering of body temperature (P < 0.05), with no effect on heart rate and a small transient delay in the increase in locomotor activity. Baclofen pretreatment (3 mg/kg) not only prolonged the time taken for animals to reach a core body temperature of 40 degrees C (P < 0.001), but also reduced the percentage of rats attaining a core body temperature of 40 degrees C. These data suggest that stimulation of GABA(B) receptors may provide a mechanism for the treatment of MDMA-induced hyperthermia.

The Neuropsychopharmacology and Toxicology of 3,4-methylenedioxy-N-ethyl-amphetamine (MDEA)

This paper reviews the pharmacology and toxicology of 3,4-methylenedioxy-N-ethylamphetamine (MDEA, "eve"). MDEA is a ring-substituted amphetamine (RSA) like MDMA, its well known N-methyl analog. Both have become very popular substances of abuse in the techno- and house-music scene. They can evoke psychomotor stimulation, mild alterations of perception, sensations of closeness and a positive emotional state as well as sympathomimetic physical effects. At present, the name "ecstasy" is no longer used only for MDMA, but for the whole group of RSAs (MDA, MDMA, MDEA and MBDB) as they are chemically and pharmacologically nearly identical; moreover, many ecstasy pills contain mixtures of the RSAs. Hence, for a selective review on MDEA, it is crucial to strictly differentiate between: 1) street and chemical names, and 2) studies with or without chemically defined substances. In order to present MDEA-specific information, the pharmacodynamics and kinetics are described on the basis of MDEA challenge studies in animals and humans. In the toxicology section, we present a collection of case reports on fatalities where MDEA was toxicologically confirmed. On the question of serotonergic neurotoxicity and possible long-term consequences, however, MDEA-specific information is available from animal studies only. The neurotoxic potential of MDEA in humans is difficult to estimate, as ecstasy users do not consume pure substances. For future research, challenge studies in animals using dosing regimens adapted to human consumption patterns are needed. Such challenge studies should directly compare individual RSAs. They will represent the most viable and fruitful approach to the resolution of the highly controversial issues of serotonergic neurotoxicity and its functional consequences.

Behavioural, hyperthermic and neurotoxic effects of 3,4-methylenedioxymethamphetamine analogues in the Wistar rat

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 preparations pre-labelled with [3H]5-HT or [3H]DA was also measured. 2. In behavioural experiments, acute MDMA and MDEA (20 mg/kg, i.p.) significantly increased rat open-field locomotion scores, decreased open-field rearing, and induced stereotypy, Straub tail and head weaving. MDBA did not produce any of these behaviours. 3. After repeated dosing (8 x 20 mg/kg, i.p., twice daily for 4 days), MDMA > MDEA >> MDBA > or = saline at decreasing forebrain [3H]paroxetine binding levels and concentrations of 5-HT and 5-HIAA at 14 days post-treatment. None of the analogues caused any long-term changes in dopamine or noradrenaline concentrations in the forebrain. 4. Acute MDMA and MDEA (20 mg/kg, i.p.) produced significant acute increases in rat aural temperature compared with saline-treated animals, while 20 mg/kg MDBA caused no significant effects. 5. MDA, MDMA and MDEA were equipotent at inducing [3H]5-HT release from frontal cortex/hippocampal synaptosomes, while MDBA only evoked a significant release at 100 microM concentrations. The potency order for inducing [3H]DA release from striatal synaptosomes was MDA > MDMA > MDEA = MDBA. 6. This study shows that large N-alkyl substitution decreases the ability of MDMA analogues to evoke presynaptic 5-HT and DA release, induce acute hyperthermia, hyperlocomotion and behavioural changes, and cause long-term serotonergic neurotoxicity. 7. The structure-activity relationship data presented here indicate that the neurotoxic damage caused by substituted amphetamines requires a combination of acute hyperthermia and increased neurotransmitter release. Induction of one of these effects in isolation is not sufficient to cause serotonergic nerve terminal degradation.