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Neuropathic and inflammatory antinociceptive effects and electrocortical changes produced by Salvia divinorum in rats

/ Neuroscience, Papers, Psychiatry & Medicine, Salvia / Salvinorin A / / , , , , , ,

Abstract

Ethnopharmacological relevance

Salvia divinorum is a medicinal plant traditionally used in hallucinogenic ethnopharmacological practices and for its analgesic and antinflammatory properties. Its active compounds include diterpenes known as salvinorins which act as potent κ opioid receptor agonists.

Aim of the study

Given its effects in acute animal models of pain, as well as its antinflammatory attributes, we decided to investigate the analgesic effects of an SD extract in neuropathic (sciatic loose nerve ligature) and inflammatory (intra plantar carrageenan) pain models in rats. We also determined in this study the electrocorticographic changes to correlate similar hallucinogenic state and behavior as those produced in humans.

Material and methods

Mechanical and thermonociceptive responses, plantar test and von Frey assay, respectively, were measured in adult Wistar rats 30 min, 3 h and 24 h after the intraperitoneal administration of saline or an hydroponic SD extract. We also evaluated carbamazepine and celecoxib, as gold reference drugs, to compare its antinociceptive effects.

Results

Our results showed that administration of SD extract induced antialgesic effects in both neuropathic and inflammatory pain models. All those effects were blocked by nor-binaltorphimine (a Kappa opioid receptor antagonist). Moreover, it was observed an increase of the anterior power spectral density and a decrease in the posterior region as electrocorticographic changes.

Conclusion

The present investigation give evidence that SD is capable to reduce algesic response associated to neuropathic and inflammatory nociception. This study support therapeutic alternatives for a disabling health problem due to the long term pain with high impact on population and personal and social implications.

Simón-Arceo, K., González-Trujano, M. E., Coffeen, U., Fernández-Mas, R., Mercado, F., Almanza, A., … & Pellicer, F. (2017). Neuropathic and inflammatory antinociceptive effects and electrocortical changes produced by Salvia divinorum in rats. Journal of Ethnopharmacology, 206, 115-124. 10.1016/j.jep.2017.05.016
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Two dose investigation of the 5-HT-agonist psilocybin on relative and global cerebral blood flow

/ Mushrooms / Psilocybin, Neuroscience, Papers / / , , , , ,

Abstract

Psilocybin, the active compound in psychedelic mushrooms, is an agonist of various serotonin receptors. Seminal psilocybin positron emission tomography (PET) research suggested regional increases in glucose metabolism in frontal cortex (hyperfrontality). However, a recent arterial spin labeling (ASL) study suggests psilocybin may lead to hypo-perfusion in various brain regions. In this placebo-controlled, double-blind study we used pseudo-continuous ASL (pCASL) to measure perfusion changes, with and without adjustment for global brain perfusion, after two doses of oral psilocybin (low dose: 0.160 mg/kg; high dose: 0.215 mg/kg) in two groups of healthy controls (n = 29 in both groups, total N = 58) during rest. We controlled for sex and age and used family-wise error corrected p values in all neuroimaging analyses. Both dose groups reported profound subjective drug effects as measured by the Altered States of Consciousness Rating Scale (5D-ASC) with the high dose inducing significantly larger effects in four out of the 11 scales. After adjusting for global brain perfusion, psilocybin increased relative perfusion in distinct right hemispheric frontal and temporal regions and bilaterally in the anterior insula and decreased perfusion in left hemispheric parietal and temporal cortices and left subcortical regions. Whereas, psilocybin significantly reduced absolute perfusion in frontal, temporal, parietal, and occipital lobes, and bilateral amygdalae, anterior cingulate, insula, striatal regions, and hippocampi. Our analyses demonstrate consistency with both the hyperfrontal hypothesis of psilocybin and the more recent study demonstrating decreased perfusion, depending on analysis method. Importantly, our data illustrate that relative changes in perfusion should be understood and interpreted in relation to absolute signal variations.
Lewis, C. R., Preller, K. H., Kraehenmann, R., Michels, L., Stämpfli, P., & Vollenweider, F. X. (2017). Two dose investigation of the 5-HT-agonist psilocybin on relative and global cerebral blood flow. NeuroImage. 10.1016/j.neuroimage.2017.07.020
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MDMA-Induced Dissociative State not Mediated by the 5-HT2A Receptor

/ MDMA, Neuroscience, Papers, Psychology, Publications / / , , , , , ,

Abstract

Previous research has shown that a single dose of MDMA induce a dissociative state, by elevating feelings of depersonalization and derealization. Typically, it is assumed that action on the 5-HT2A receptor is the mechanism underlying these psychedelic experiences. In addition, other studies have shown associations between dissociative states and biological parameters (heart rate, cortisol), which are elevated by MDMA. In order to investigate the role of the 5-HT2 receptor in the MDMA-induced dissociative state and the association with biological parameters, a placebo-controlled within-subject study was conducted including a single oral dose of MDMA (75 mg), combined with placebo or a single oral dose of the 5-HT2 receptor blocker ketanserin (40 mg). Twenty healthy recreational MDMA users filled out a dissociative states scale (CADSS) 90 min after treatments, which was preceded and followed by assessment of a number of biological parameters (cortisol levels, heart rate, MDMA blood concentrations). Findings showed that MDMA induced a dissociative state but this effect was not counteracted by pre-treatment with ketanserin. Heart rate was the only biological parameter that correlated with the MDMA-induced dissociative state, but an absence of correlation between these measures when participants were pretreated with ketanserin suggests an absence of directional effects of heart rate on dissociative state. It is suggested that the 5-HT2 receptor does not mediate the dissociative effects caused by a single dose of MDMA. Further research is needed to determine the exact neurobiology underlying this effect and whether these effects contribute to the therapeutic potential of MDMA.
Puxty, D. J., Ramaekers, J. G., de la Torre, R., Farré, M., Pizarro, N., Pujadas, M., & Kuypers, K. P. (2017). MDMA-induced dissociative state not mediated by the 5-HT2A receptor. Frontiers in pharmacology, 8, 455. 10.3389/fphar.2017.00455
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A Physician’s Attempt to Self-Medicate Bipolar Depression with N,N-Dimethyltryptamine (DMT)

/ Depressive Disorders, DMT, Papers, Psychology / / , , , ,

Abstract

N,N-dimethyltryptamine (DMT) is a psychoactive substance that has been gaining popularity in therapeutic and recreational use. This is a case of a physician who chronically took DMT augmented with phenelzine in an attempt to self-medicate refractory bipolar depression. His presentation of altered mental status, mania, and psychosis is examined in regards to his DMT use. This case discusses DMT, the possible uses of DMT, and the theorized mechanism of DMT in psychosis and treatment of depression, particularly involving its agonist activity at 5-HT1A, 5-HT2A, and 5-HT2C. It is also important to recognize the dangers of self-medication, particularly amongst physicians.
Brown, T., Shao, W., Ayub, S., Chong, D., Cornelius, C. A Physician’s Attempt to Self-Medicate Bipolar Depression with N,N-Dimethyltryptamine (DMT). Journal of Psychoactive Drugs. 10.1080/02791072.2017.1344898
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Hallucinogens and Serotonin 5-HT2A Receptor-Mediated Signaling Pathways

/ LSD, Mescaline / Cacti, Mushrooms / Psilocybin, Neuroscience, Papers / / ,

Abstract

The neuropsychological effects of naturally occurring psychoactive chemicals have been recognized for millennia. Hallucinogens, which include naturally occurring chemicals such as mescaline and psilocybin, as well as synthetic compounds, such as lysergic acid diethylamide (LSD), induce profound alterations of human consciousness, emotion, and cognition. The discovery of the hallucinogenic effects of LSD and the observations that LSD and the endogenous ligand serotonin share chemical and pharmacological profiles led to the suggestion that biogenic amines like serotonin were involved in the psychosis of mental disorders such as schizophrenia. Although they bind other G protein-coupled receptor (GPCR) subtypes, studies indicate that several effects of hallucinogens involve agonist activity at the serotonin 5-HT2Areceptor. In this chapter, we review recent advances in understanding hallucinogen drug action through characterization of structure, neuroanatomical location, and function of the 5-HT2A receptor.
López-Giménez, J. F., & González-Maeso, J. (2017). Hallucinogens and Serotonin 5-HT2A Receptor-Mediated Signaling Pathways. 10.1007/7854_2017_478
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The Effects of Hallucinogens on Gene Expression

/ LSD, Neuroscience, Papers / / ,

Abstract

The classic serotonergic hallucinogens, or psychedelics, have the ability to profoundly alter perception and behavior. These can include visual distortions, hallucinations, detachment from reality, and mystical experiences. Some psychedelics, like LSD, are able to produce these effects with remarkably low doses of drug. Others, like psilocybin, have recently been demonstrated to have significant clinical efficacy in the treatment of depression, anxiety, and addiction that persist for at least several months after only a single therapeutic session. How does this occur? Much work has recently been published from imaging studies showing that psychedelics alter brain network connectivity. They facilitate a disintegration of the default mode network, producing a hyperconnectivity between brain regions that allow centers that do not normally communicate with each other to do so. The immediate and acute effects on both behaviors and network connectivity are likely mediated by effector pathways downstream of serotonin 5-HT2A receptor activation. These acute molecular processes also influence gene expression changes, which likely influence synaptic plasticity and facilitate more long-term changes in brain neurochemistry ultimately underlying the therapeutic efficacy of a single administration to achieve long-lasting effects. In this review, we summarize what is currently known about the molecular genetic responses to psychedelics within the brain and discuss how gene expression changes may contribute to altered cellular physiology and behaviors.
Martin, D. A., & Nichols, C. D. (2017). The Effects of Hallucinogens on Gene Expression. 10.1007/7854_2017_479
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LSD treatment in Scandinavia: emphasizing indications and short-term treatment outcomes of 151 patients in Denmark

/ LSD, Papers, Psychology / /

Abstract

BACKGROUND:
New research has suggested the clinical use of lysergic acid diethylamide (LSD) and psilocybin in selected patient populations. However, concerns about the clinical use of LSD were advanced in a large Danish follow-up study that assessed 151 LSD-treated psychiatric patients approximately 25 years after their treatment in the 1960s.
AIMS:
The purpose of the present study was to give a retrospective account of the short-term outcome of LSD treatment in these 151 Danish psychiatric patients.
METHODS:
The LSD case material in the Danish State Archives consists of medical case records of 151 LSD-treated patients, who complained and received economic compensation with the LSD Damages Law. The author carefully read and reviewed the LSD case material.
RESULTS:
LSD was used to treat a wide spectrum of mental disorders. Independent of diagnoses, 52 patients improved, and 48 patients worsened acutely with the LSD treatment. In a subgroup of 82 neurotic patients, the LSD dose-index (number of treatments multiplied by the maximal LSD dose) indicated the risk of acute worsening. In another subgroup of 19 patients with obsessive-compulsive neurosis, five patients later underwent psychosurgery. A small subgroup of 12 patients was treated with psilocybin. The long-term outcome was poor in most of the patients.
CONCLUSIONS:
Despite the significant limitations to a retrospective design, this database warrants caution in mental health patients. The use of LSD and psilocybin in mental health patients may be associated with serious short- and long-term side effects. Until further trials with rigorous designs have cleared these drugs of their potential harms, their clinical utility in these groups of patients has not been fully clarified.
Larsen, J. K. (2017). LSD treatment in Scandinavia: emphasizing indications and short-term treatment outcomes of 151 patients in Denmark. Nordic Journal of Psychiatry, 1-7. 10.1080/08039488.2017.1336251
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Online survey – are you planning to use psychedelics?

/ Publications /

psychedelic surveyResearchers at Imperial College, London have started an online observational study into the acute and long-term psychological effects of psychedelics. OPEN is a sponsor of this study.

The researchers aim to recruit individuals who are planning to take a psychedelic drug on their own initiative. You can sign up at their website and will subsequently receive several surveys before and after their psychedelic experience.
So, if you are or know anyone who has planned to take a psychedelic in the near future, please encourage them to sign up! More information on this study can be found at the Psychedelic Survey website, on facebook or on twitter.

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Ketamine for Depression, 4: In What Dose, at What Rate, by What Route, for How Long, and at What Frequency?

/ Depressive Disorders, Ketamine, Papers, Psychology, Publications / /

Abstract

BACKGROUND:
Ketamine, administered in subanesthetic doses, is an effective off-label treatment for severe and even treatment-refractory depression; however, despite dozens of studies across nearly 2 decades of research, there is no definitive guidance on matters related to core practice issues.
METHODS:
This article presents a qualitative review and summary about what is known about ketamine dosing, rate of administration, route of administration, duration of treatment, and frequency of sessions.
RESULTS:
Ketamine is most commonly administered in the dose of 0.5 mg/kg, but some patients may respond to doses as low as 0.1 mg/kg, and others may require up to 0.75 mg/kg. The ketamine dose is conventionally administered across 40 minutes; however, safety and efficacy have been demonstrated in sessions ranging between 2 and 100 minutes in duration. Bolus administration is safe and effective when the drug is administered intramuscularly or subcutaneously. Whereas the intravenous route is the most commonly employed, safety and efficacy have been described with other routes of administration, as well; these include oral, sublingual, transmucosal, intranasal, intramuscular, and subcutaneous routes. Patients may receive a single session of treatment or a course of treatment during the acute phase, and treatment may rarely be continued for weeks to years to extend and maintain treatment gains in refractory cases. When so extended, the ideal frequency is perhaps best individualized wherein ketamine is dosed a little before the effect of the previous session is expected to wear off.
CONCLUSIONS:
There is likely to be a complex interaction between ketamine dose, session duration, route of administration, frequency of administration, and related practice. Until definitive studies comparing different doses, rates of administration, routes of administration, and other considerations are conducted, firm recommendations are not possible. From the point of view of clinical practicability, subcutaneous, intranasal, and oral ketamine warrant further study. If domiciliary treatment is considered, the risk of abuse must be kept in mind.
Andrade, C. (2017). Ketamine for Depression, 4: In What Dose, at What Rate, by What Route, for How Long, and at What Frequency?. The Journal of clinical psychiatry, 78(7), e852-e857. 10.4088/JCP.17f11738
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Ayahuasca: what mental health professionals need to know

/ Anxiety Disorders / PTSD, Ayahuasca, Biology & Ethnobotany, Depressive Disorders, Papers, Psychology, Publications, Substance Use Disorder / / , ,

Abstract

Background

Ayahuasca is a psychoactive ethnobotanical concoction that has been used for decades by indigenous groups of the Northwestern Amazon and by syncretic religious organizations for ritual and therapeutic purposes. In the last two decades, it is being used worldwide in evolving practices. Ayahuasca seem to therapeutic effects, but controlled studies are lacking. Moreover, its safety and toxicity are not completely understood.

Objectives

To present an overview of the effects of ayahuasca based on the most recent human studies.

Methods

Narrative review.

Results

Ayahuasca administration in controlled settings appears to be safe from a subjective and physiological perspective, with few adverse reactions being reported. More frequent adverse reactions occur in non-controlled settings. Prolonged psychotic reactions are rare and seem to occur especially in susceptible individuals. Ayahuasca showed antidepressive, anxiolytic, and antiaddictive effects in animal models, observational studies, and in open-label and controlled studies.

Discussion

Ayahuasca administration in controlled settings appear to be safe. Moreover, ayahuasca seem to have therapeutic effects for treatment-resistant psychiatric disorders that should be further investigated in randomized controlled clinical trials. However, medical complications and cases of prolonged psychotic reactions have been reported, and people with personal or family history of psychotic disorders should avoid ayahuasca intake.

Santos, R. G. D., Bouso, J. C., & Hallak, J. E. C. (2017). Ayahuasca: what mental health professionals need to know. Archives of Clinical Psychiatry (São Paulo), 44(4), 103-109. 10.1590/0101-60830000000130
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