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Neuroscience

Neurochemical and Behavioral Profiling in Male and Female Rats of the Psychedelic Agent 25I-NBOMe

December 12, 2019 / LSD, MDMA, Neuroscience, Papers, Publications / By / , , , , , ,

Abstract

4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl)phenethylamine (25I-NBOMe), commonly called “N-Bomb,” is a synthetic phenethylamine with psychedelic and entactogenic effects; it was available on the Internet both as a legal alternative to lysergic acid diethylamide (LSD) and as a surrogate of 3,4-methylenedioxy-methamphetamine (MDMA), but now it has been scheduled among controlled substances. 25I-NBOMe acts as full agonist on serotonergic 5-HT2A receptors. Users are often unaware of ingesting fake LSD, and several cases of intoxication and fatalities have been reported. In humans, overdoses of “N-Bomb” can cause tachycardia, hypertension, seizures, and agitation. Preclinical studies have not yet widely investigated the rewarding properties and behavioral effects of this compound in both sexes. Therefore, by in vivo microdialysis, we evaluated the effects of 25I-NBOMe on dopaminergic (DA) and serotonergic (5-HT) transmissions in the nucleus accumbens (NAc) shell and core, and the medial prefrontal cortex (mPFC) of male and female rats. Moreover, we investigated the effect of 25I-NBOMe on sensorimotor modifications as well as body temperature, nociception, and startle/prepulse inhibition (PPI). We showed that administration of 25I-NBOMe affects DA transmission in the NAc shell in both sexes, although showing different patterns; moreover, this compound causes impaired visual responses in both sexes, whereas core temperature is heavily affected in females, and the highest dose tested exerts an analgesic effect prominent in male rats. Indeed, this drug is able to impair the startle amplitude with the same extent in both sexes and inhibits the PPI in male and female rats. Our study fills the gap of knowledge on the behavioral effects of 25I-NBOMe and the risks associated with its ingestion; it focuses the attention on sex differences that might be useful to understand the trend of consumption as well as to recognize and treat intoxication and overdose symptoms.

Miliano, C., Marti, M., Pintori, N., Castelli, M. P., Tirri, M., Arfè, R., & De Luca, M. A. (2019). Neurochemical and Behavioral Profiling in Male and Female Rats of the Psychedelic Agent 25I-NBOMe. Frontiers in Pharmacology, 10., 10.3389/fphar.2019.01406
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4-MeO-PCP and 3-MeO-PCMo, new dissociative drugs, produce rewarding and reinforcing effects through activation of mesolimbic dopamine pathway and alteration of accumbal CREB, deltaFosB, and BDNF levels

December 11, 2019 / Neuroscience, Papers, Pharmacology & Chemistry, Psychiatry & Medicine, Publications, Substance Use Disorder / By / , , , , , ,

Abstract

Rationale: A high number of synthetic dissociative drugs continue to be available through online stores, leading to their misuse. Recent inclusions in this category are 4-MeO-PCP and 3-MeO-PCMo, analogs of phencyclidine. Although the dissociative effects of these drugs and their recreational use have been reported, no studies have investigated their abuse potential.

Objectives: To examine their rewarding and reinforcing effects and explore the mechanistic correlations.

Methods: We used conditioned place preference (CPP), self-administration, and locomotor sensitization tests to assess the rewarding and reinforcing effects of the drugs. We explored their mechanism of action by pretreating dopamine receptor (DR) D1 antagonist SCH23390 and DRD2 antagonist haloperidol during CPP test and investigated the effects of 4-MeO-PCP and 3-MeO-PCMo on dopamine-related proteins in the ventral tegmental area and nucleus accumbens. We also measured the levels of dopamine, phosphorylated cyclic-AMP response element-binding (p-CREB) protein, deltaFosB, and brain-derived neurotrophic factor (BDNF) in the nucleus accumbens. Additionally, we examined the effects of both drugs on brain wave activity using electroencephalography.

Results: While both 4-MeO-PCP and 3-MeO-PCMo induced CPP and self-administration, only 4-MeO-PCP elicited locomotor sensitization. SCH23390 and haloperidol inhibited the acquisition of drug CPP. 4-MeO-PCP and 3-MeO-PCMo altered the levels of tyrosine hydroxylase, DRD1, DRD2, and dopamine, as well as that of p-CREB, deltaFosB, and BDNF. All drugs increased the delta and gamma wave activity, whereas pretreatment with SCH23390 and haloperidol inhibited it.

Conclusion: Our results indicate that 4-MeO-PCP and 3-MeO-PCMo induce rewarding and reinforcing effects that are probably mediated by the mesolimbic dopamine system, suggesting an abuse liability in humans.

Abiero, A., Botanas, C. J., Custodio, R. J., Sayson, L. V., Kim, M., Lee, H. J., … & Cheong, J. H. (2020). 4-MeO-PCP and 3-MeO-PCMo, new dissociative drugs, produce rewarding and reinforcing effects through activation of mesolimbic dopamine pathway and alteration of accumbal CREB, deltaFosB, and BDNF levels. Psychopharmacology, 237(3), 757-772; 10.1007/s00213-019-05412-y

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Prospective examination of synthetic 5-methoxy-N,N-dimethyltryptamine inhalation: effects on salivary IL-6, cortisol levels, affect, and non-judgment

December 10, 2019 / DMT, Neuroscience, Papers, Pharmacology & Chemistry, Psychiatry & Medicine, Publications / By / , , , , ,

Abstract

Rationale

5-methoxy-N,N-dimethyltryptamine is a psychotropic substance found in various plant and animal species and is synthetically produced. 5-methoxy-N,N-dimethyltryptamine is used in naturalistic settings for spiritual exploration, recreation, or to address negative affect and mood problems. However, scientific knowledge on the effects of 5-methoxy-N,N-dimethyltryptamine in humans is scarce.

Objectives

The first objective was to assess the effects of inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine on neuroendocrine markers. The second objective was to assess effects of the substance on affect and mindfulness. In addition, we assessed whether ratings of subjective measures were associated with changes in stress biomarkers (i.e., cortisol) and immune response (i.e., IL-6, CRP, IL-1β), as well as the acute psychedelic experience.

Methods

Assessments (baseline, immediately post-session, and 7-day follow-up) were made in 11 participants. Salivary samples were collected at baseline and post-session and analyzed by high-sensitivity enzyme-linked immunosorbent assay (ELISA).

Results

5-methoxy-N,N-dimethyltryptamine significantly increased cortisol levels and decreased IL-6 concentrations in saliva immediately post-session. These changes were not correlated to ratings of mental health or the psychedelic experience. Relative to baseline, ratings of non-judgment significantly increased, and ratings of depression decreased immediately post-session and at follow-up. Ratings of anxiety and stress decreased from baseline to 7-day follow-up. Participant ratings of the psychedelic experience correlated negatively with ratings of affect and positively with ratings of non-judgment.

Conclusion

Inhalation of vaporized synthetic 5-methoxy-N,N-dimethyltryptamine produced significant changes in inflammatory markers, improved affect, and non-judgment in volunteers. Future research should examine the effect of 5-methoxy-N,N-dimethyltryptamineamine with healthy volunteers in a controlled laboratory setting.

Uthaug, M. V., Lancelotta, R., Szabo, A., Davis, A. K., Riba, J., & Ramaekers, J. G. (2019). Prospective examination of synthetic 5-methoxy-N, N-dimethyltryptamine inhalation: effects on salivary IL-6, cortisol levels, affect, and non-judgment. Psychopharmacology, 1-13., 10.1007/s00213-019-05414-w
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Locomotor effects of 3,4-methylenedioxymethamphetamine (MDMA) and its deuterated form in mice: psychostimulant effects, stereotypy, and sensitization

November 15, 2019 / MDMA, Neuroscience, Papers, Pharmacology & Chemistry, Publications / By / , , ,

Abstract

Rationale

There is a renewed interest in the use of 3,4-methylenedioxymethamphetamine (MDMA) for treating psychiatric conditions. Although MDMA has entered phase II clinical trials and shows promise as an adjunct treatment, there is an extensive literature detailing the potential neurotoxicity and adverse neurobehavioral effects associated with MDMA use. Previous research indicates that the adverse effects of MDMA may be due to its metabolism into reactive catechols that can enter the brain and serve directly as neurotoxicants. One approach to mitigate MDMA’s potential for adverse effects is to reduce O-demethylation by deuterating the methylenedioxy ring of MDMA. There are no studies that have evaluated the effects of deuterating MDMA on behavioral outcomes.

Objectives

The purpose of the present study was to assess the motor-stimulant effects of deuterated MDMA (d2-MDMA) and compare them to MDMA in male mice.

Methods

Two experiments were performed to quantify mouse locomotor activity and to vary the drug administration regimen (single bolus administration or cumulative administration).

Results

The results of Experiments 1 and 2 indicate that d2-MDMA is less effective at eliciting horizontal locomotion than MDMA; however, the differences between the compounds diminish as the number of cumulative administrations increase. Both d2-MDMA and MDMA can elicit sensitized responses, and these effects cross-sensitize to the prototypical drug of abuse methamphetamine. Thus, d2-MDMA functions as a locomotor stimulant similar to MDMA, but, depending on the dosing regimen, may be less susceptible to inducing sensitization to stereotyped movements.

Conclusions

These findings indicate that d2-MDMA is behaviorally active and produces locomotor effects that are similar to MDMA, which warrant additional assessments of d2-MDMA’s behavioral and physiological effects to determine the conditions under which this compound may serve as a relatively safer alternative to MDMA for clinical use.
Berquist, M. D., Leth-Petersen, S., Kristensen, J. L., & Fantegrossi, W. E. (2020). Locomotor effects of 3, 4-methylenedioxymethamphetamine (MDMA) and its deuterated form in mice: psychostimulant effects, stereotypy, and sensitization. Psychopharmacology, 237(2), 431-442; https://doi.org/10.1007/s00213-019-05380-3

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Effects of the hallucinogenic beverage ayahuasca on voluntary ethanol intake by rats and on cFos expression in brain areas relevant to drug addiction

February 6, 2022 / Ayahuasca, Neuroscience, Papers, Substance Use Disorder / Leave a Comment / By / , , , , ,

Abstract

Ayahuasca is a hallucinogenic infusion used in religious rituals that has serotoninergic properties and may be a potential therapeutic option for drug addiction. In this study, Wistar rats had intermittent access to ethanol for 8 weeks, receiving water (control), naltrexone (NTX, 2 mg/kg body weight [bw] intraperitoneally [i.p.]) or ayahuasca (Aya) at 0.5x, 1x, or 2x the ritual dose in the final 5 days. A naïve group had access only to water. Ethanol intake was estimated throughout the experiment, and cFos expression was evaluated in medial orbital cortex (MO), ventral orbital cortex (VO), lateral orbital cortex (LO), nucleus accumbens (NAc), and striatum. Treatment with either NTX or Aya (oral) did not decrease ethanol intake compared to the baseline level (5th to 7th week), but the NTX group intake was significantly lower than controls (p < 0.05). Ethanol significantly increased cFos expression in the MO region for control (p < 0.0001), NTX (p < 0.05), Aya1 (p < 0.001), and Aya2 (p < 0.0001) groups. This increase was also observed in the VO for the Aya1 group (p = 0.035), in the LO for the Aya2 group (p < 0.01), and in NAc for NTX and ayahuasca groups (p < 0.005). Furthermore, NTX and Aya0.5 treatment decreased cFos expression compared to controls in the MO region (p < 0.05 and p < 0.01, respectively), but only the ayahuasca group reached levels not significantly different from the naïve group. Studies using other protocols and dose regime are necessary to better investigate the impact of ayahuasca on alcohol intake by rats to support the observations in humans. Additionally, the role of ayahuasca in mediating cFos expression in other selected brain regions and its relationship with the serotoninergic/dopaminergic systems and drug addiction need further investigation.

Nolli, L. M., de Oliveira, D., Alves, S. S., von Zuben, M. V., Pic-Taylor, A., Mortari, M. R., & Caldas, E. D. (2020). Effects of the hallucinogenic beverage ayahuasca on voluntary ethanol intake by rats and on cFos expression in brain areas relevant to drug addiction. Alcohol (Fayetteville, N.Y.), 84, 67–75. https://doi.org/10.1016/j.alcohol.2019.10.005

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Acute effects of lysergic acid diethylamide (LSD) on resting brain function.

September 30, 2019 / LSD, Neuroscience, Papers, Psychology, Publications / By / ,

Abstract

Lysergic acid diethylamide (LSD) is a potent hallucinogenic substance that was extensively investigated by psychiatrists during the 1950s and 1960s. Researchers were interested in the unique effects induced by this substance, some of which resemble symptoms seen in schizophrenia. Moreover, during that period LSD was studied and used for the treatment of several mental disorders such as depression, anxiety, addiction and personality disorders. Despite this long history of research, how LSD induces its specific effects on a neuronal level has been relatively unclear. In recent years there has been a revival of research in hallucinogenic drugs and their possible clinical applications. These contemporary studies in the UK and Switzerland include neuroimaging studies using functional magnetic resonance imaging (fMRI). In this review, we collect and interpret these recent neuroimaging findings. Overall, previous results across studies indicate that LSD administration is associated with extensive alterations in functional brain connectivity, measuring the correlated activities between different brain regions. The studies mostly reported increases in connectivity between regions and, more specifically, consistently found increased connectivity within the thalamocortical system. These latter observations are in agreement with models proposing that hallucinogenic drugs exert their effects by inhibiting cerebral filtering of external and internal data. However, studies also face several limitations, including potential biases of neuroimaging measurements.
Müller, F., & Borgwardt, S. (2019). Acute effects of lysergic acid diethylamide (LSD) on resting brain function. Swiss Medical Weekly, 149(3940)., https://doi.org/10.4414/smw.2019.20124
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The Psilocybin-Telomere Hypothesis: An Empirically Falsifiable Prediction Concerning the Beneficial Neuropsychopharmacological Effects of Psilocybin on Genetic Aging

September 24, 2019 / Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By /

Abstract

We introduce a novel hypothesis which states that the therapeutic utilisation of psilocybin has beneficial effects on genetic aging. Ex hypothesi, we predict a priori that controlled psilocybin interventions exert quantifiable positive impact on leucocyte telomere length (telomeres are a robust predictor of mortality and multifarious aging-related diseases). Our hypothesising follows the Popperian logic of scientific discovery, viz., bold (and refutable) conjectures form the very foundation of scientific progress. The ‘psilocybin-telomere hypothesis’ is formalised as a logically valid deductive (syllogistic) argument and we provide substantial evidence to support the underlying premises. Impetus for our theorising derives from a plurality of converging empirical sources indicating that psilocybin has persistent beneficial effects on various aspects of mental health (e.g., in the context of depression, anxiety, PTSD, OCD, addiction, etc.). Additional support is based on a large corpus of studies that establish reliable correlations between mental health and telomere attrition (improved mental health is generally correlated with longer telomeres). Another pertinent component of our argument is based on recent studies which demonstrate that “meditative states of consciousness” provide beneficial effects on genetic aging. Similarly, psilocybin can induce states of consciousness that are neurophysiologically and phenomenologically significantly congruent with meditative states. Furthermore, prior research has demonstrated that a single dose of psilocybin can occasion life-changing transformative experiences (≈ 70% of healthy volunteers rate their experience with psilocybin amongst the five personally most meaningful lifetime events, viz., ranked next to giving birth to a child or losing a loved one). We postulate that these profound psychological events leave quantifiable marks at the molecular genetic/epigenetic level. Given the ubiquitous availability and cost effectiveness of telomere length assays, we suggest that quantitative telomere analysis should be regularly included in future psilocybin studies as an adjunctive biological marker (i.e., to facilitate scientific consilience via methodological triangulation). In order to substantiate the ‘psilocybin-telomere hypothesis’ potential neuropsychopharmacological, endocrinological, and genetic mechanisms of action are discussed (e.g., HPA-axis reactivity, hippocampal neurogenesis, neurotropic growth factors such as BDNF, 5-HT2A receptor agonism, neuroplasticity/synaptoplasticity, brain-wide alterations in neuronal functional connectivity density, involvement of the SLC6A4 serotonin transporter gene, inter alia). The proposed research agenda is thus intrinsically highly interdisciplinary, and it has deep ramifications from a philosophy of science perspective as it connects the epistemic level (qualitative experiential phenomenology) with the ontic level (quantitative molecular genetics) of analysis. In the long term, multidisciplinary and innovative investigations of the ‘psilocybin-telomere hypothesis’ could contribute to the improvement of senotherapeutic psychological interventions and the identification of novel geroprotective and neuroprotective/restorative pharmaceutical targets to decelerate genetic aging and improve well-being and quality of life during the aging process.
Germann, C. B. (2020). The Psilocybin-Telomere Hypothesis: An empirically falsifiable prediction concerning the beneficial neuropsychopharmacological effects of psilocybin on genetic aging. Medical hypotheses, 134, 109406., https://doi.org/10.1016/j.mehy.2019.109406
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The psychedelic renaissance: the next trip for psychiatry?

September 23, 2019 / Depressive Disorders, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By

Abstract

The psychedelic research renaissance is gaining traction. Preliminary clinical studies of the hallucinogenic fungi, psilocybin, with psychological support, have indicated improvements in mood, anxiety and quality of life. A seminal, open-label study demonstrated marked reductions in depression symptoms in participants with treatment-resistant depression (TRD). The associated neurobiological processes involve alterations in brain connectivity, together with altered amygdala and default mode network activity. At the cellular level, psychedelics promote synaptogenesis and neural plasticity. Prompted by the promising preliminary studies, a randomized, double-blind trial has recently been launched across Europe and North America to investigate the efficacy of psilocybin in TRD. One of these centres is based in Ireland – CHO Area 7 and Tallaght University Hospital. The outcome of this trial will determine whether psilocybin with psychological support will successfully translate into the psychiatric clinic for the benefit of patients.
Kelly, J. R., Baker, A., Babiker, M., Burke, L., Brennan, C., & O’Keane, V. (2019). The psychedelic renaissance: the next trip for psychiatry?. Irish journal of psychological medicine, 1-5., https://doi.org/10.1017/ipm.2019.39
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The Impact of Childhood Maltreatment on Intravenous Ketamine Outcomes for Adult Patients with Treatment-Resistant Depression

September 11, 2019 / Anxiety Disorders / PTSD, Depressive Disorders, Ketamine, Neuroscience, Papers, Psychiatry & Medicine, Publications / By / , , , ,

Abstract

Childhood maltreatment is associated with a poor treatment response to conventional antidepressants and increased risk for treatment-resistant depression (TRD). The N-methyl-D-aspartate receptor (NDMAR) antagonist ketamine has been shown to rapidly improve symptoms of depression in patients with TRD. It is unknown if childhood maltreatment could influence ketamine’s treatment response. We examined the relationship between childhood maltreatment using the Childhood Trauma Questionnaire (CTQ) and treatment response using the Quick Inventory of Depressive Symptoms-Self Report (QIDS-SR) in TRD patients receiving intravenous ketamine at a community outpatient clinic. We evaluated treatment response after a single infusion (n = 115) and a course of repeated infusions (n = 63). Repeated measures general linear models and Bayes factor (BF) showed significant decreases in QIDS-SR after the first and second infusions, which plateaued after the third infusion. Clinically significant childhood sexual abuse, physical abuse, and cumulative clinically significant maltreatment on multiple domains (maltreatment load) were associated with better treatment response to a single and repeated infusions. After repeated infusions, higher load was also associated with a higher remission rate. In contrast to conventional antidepressants, ketamine could be more effective in TRD patients with more childhood trauma burden, perhaps due to ketamine’s proposed ability to block trauma-associated behavioral sensitization.

O’Brien, B., Lijffijt, M., Wells, A., Swann, A. C., & Mathew, S. J. (2019). The impact of childhood maltreatment on intravenous ketamine outcomes for adult patients with treatment-resistant depression. Pharmaceuticals, 12(3), 133., 10.3390/ph12030133
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Hallucinogens and Their Therapeutic Use: A Literature Review

September 1, 2019 / Anxiety Disorders / PTSD, Ayahuasca, Depressive Disorders, DMT, Iboga / Ibogaine, Ketamine, LSD, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By / ,

Abstract

The exploration of possible therapeutic benefits of hallucinogenic substances has undergone a revitalization in the past decade. This literature review investigated the published literature regarding the psychotherapeutic uses of hallucinogens in psychiatric disorders. The results showed that a variety of substances have been evaluated in the treatment of psychiatric disorders, including ayahuasca, ibogaine, ketamine, lysergic acid diethylamide, 3,4-methylenedioxymethamphetamine, and psilocybin. The conditions treated ranged from depression to autism, with the largest volume of research dedicated to substance use disorders. The majority of studies that were reviewed demonstrated significant associations with improvement in the conditions investigated. However, it was difficult to draw definitive conclusions as most studies suffered from small sample sizes, inconsistent measures, and poor study design. To properly assess the risks and potential benefits of hallucinogens in psychiatric treatment, there is a need for well designed, standardized studies that demonstrate the impact of hallucinogenic substances on psychiatric conditions.

BEGOLA, M. J., & SCHILLERSTROM, J. E. (2019). Hallucinogens and Their Therapeutic Use: A Literature Review. Journal of Psychiatric Practice®, 25(5), 334-346., 10.1097/PRA.0000000000000409
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