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The effect of Banisteriopsis caapi (B. caapi) on the motor deficits in the MPTP-treated common marmoset model of Parkinson’s disease

January 24, 2018 / Ayahuasca, Neuroscience, Papers, Psychiatry & Medicine, Publications / By / , , , , , ,

Abstract

Banisteriopsis caapi (B. caapi) contains harmine, harmaline, and tetrahydroharmine, has monoamine oxidase inhibitory activity, and has reported antiparkinsonian activity in humans when imbibed as a tea; however, its effects are poorly documented. For this reason, motor function was assessed in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets following administration of B. caapi extract (28.4–113.6 mg/kg; po), harmine (0.1 and 0.3 mg/kg; sc), and selegiline (10 mg/kg; sc), alone or with a submaximal dose of L-3,4-dihydroxyphenylalanine (L-DOPA; 4–7 mg/kg). L-DOPA reversed motor disability, increased locomotor activity, and induced moderate dyskinesia. B. caapi did not increase locomotor activity or induce dyskinesia but at 56.8 and 113.6 mg/kg improved motor disability. The L-DOPA response was unaltered by co-administration of B. caapi. Harmine (0.1 and 0.3 mg/kg) produced a mild improvement in motor disability without affecting locomotor activity or dyskinesia but had no effect on the L-DOPA-induced antiparkinsonian response. Selegiline (10 mg/kg) alone improved motor function to the same extent as L-DOPA, but with only mild dyskinesia, and did not alter the response to L-DOPA, although dyskinesia was reduced. The findings suggest that B. caapi alone has a mild antiparkinsonian effect but does not enhance the L-DOPA response or reduce dyskinesia.
Fisher, R., Lincoln, L., Jackson, M. J., Abbate, V., Jenner, P., Hider, R., … & Rose, S. (2018). The effect of Banisteriopsis caapi (B. caapi) on the motor deficits in the MPTP‐treated common marmoset model of Parkinson’s disease. Phytotherapy Research. 10.1002/ptr.6017
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The effect of Banisteriopsis caapi (B. caapi) on the motor deficits in the MPTP-treated common marmoset model of Parkinson's disease

January 24, 2018 / Ayahuasca, Neuroscience, Papers, Psychiatry & Medicine, Publications / By / , , , , , ,

Abstract

Banisteriopsis caapi (B. caapi) contains harmine, harmaline, and tetrahydroharmine, has monoamine oxidase inhibitory activity, and has reported antiparkinsonian activity in humans when imbibed as a tea; however, its effects are poorly documented. For this reason, motor function was assessed in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets following administration of B. caapi extract (28.4–113.6 mg/kg; po), harmine (0.1 and 0.3 mg/kg; sc), and selegiline (10 mg/kg; sc), alone or with a submaximal dose of L-3,4-dihydroxyphenylalanine (L-DOPA; 4–7 mg/kg). L-DOPA reversed motor disability, increased locomotor activity, and induced moderate dyskinesia. B. caapi did not increase locomotor activity or induce dyskinesia but at 56.8 and 113.6 mg/kg improved motor disability. The L-DOPA response was unaltered by co-administration of B. caapi. Harmine (0.1 and 0.3 mg/kg) produced a mild improvement in motor disability without affecting locomotor activity or dyskinesia but had no effect on the L-DOPA-induced antiparkinsonian response. Selegiline (10 mg/kg) alone improved motor function to the same extent as L-DOPA, but with only mild dyskinesia, and did not alter the response to L-DOPA, although dyskinesia was reduced. The findings suggest that B. caapi alone has a mild antiparkinsonian effect but does not enhance the L-DOPA response or reduce dyskinesia.
Fisher, R., Lincoln, L., Jackson, M. J., Abbate, V., Jenner, P., Hider, R., … & Rose, S. (2018). The effect of Banisteriopsis caapi (B. caapi) on the motor deficits in the MPTP‐treated common marmoset model of Parkinson’s disease. Phytotherapy Research. 10.1002/ptr.6017
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Depressive mood ratings are reduced by MDMA in female polydrug ecstasy users homozygous for the l-allele of the serotonin transporter

January 18, 2018 / MDMA, Neuroscience, Papers, Psychology, Publications / By / , , , , , ,

Abstract

MDMA exerts its main effects via the serotonergic system and the serotonin transporter. The gene coding for this transporter determines the expression rate of the transporter. Previously it was shown that healthy individuals with the short allelic variant (‘s-group’) of the 5-HTTLPR-polymorphism displayed more anxiety and negative mood, and had a lower transcriptional efficiency compared to individuals who are homozygous for the l-allele (‘l-group’). The present study aimed to investigate the role of the 5-HTTLPR polymorphism in MDMA-induced mood effects. Four placebo-controlled, within-subject studies were pooled, including in total 63 polydrug ecstasy users (Ns-group = 48; Nl-group = 15) receiving MDMA 75 mg and placebo on two test days, separated by minimally 7 days. Mood was assessed by means of the Profile of Mood States. Findings showed that MDMA induced -independent of sex- a positive mood state, and as a side effect also increased two negative affect states, anxiety and confusion. Anxiety ratings were higher in the l-group and independent of treatment or sex. Depression ratings were lowered by MDMA in the female l-group. Findings indicate that the MDMA-induced reduction in self-rated depressive feelings is sex- and genotype-dependent, with females homozygous for the l-allele showing this beneficial effect.
Kuypers, K. P. C., de la Torre, R., Farre, M., Xicota, L., Perna, E. D. S. F., Theunissen, E. L., & Ramaekers, J. G. (2018). Depressive mood ratings are reduced by MDMA in female polydrug ecstasy users homozygous for the l-allele of the serotonin transporter. Scientific reports, 8(1), 1061. 10.1038/s41598-018-19618-1
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Psilocybin disrupts sensory and higher order cognitive processing but not pre-attentive cognitive processing—study on P300 and mismatch negativity in healthy volunteers

January 5, 2018 / Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Psychotic Disorders, Publications / By / , , , , , ,

Abstract

Rationale

Disruption of auditory event-related evoked potentials (ERPs) P300 and mismatch negativity (MMN), electrophysiological markers of attentive and pre-attentive cognitive processing, is repeatedly described in psychosis and schizophrenia. Similar findings were observed in a glutamatergic model of psychosis, but the role of serotonergic 5-HT2A receptors in information processing is less clear.

Objectives

We studied ERPs in a serotonergic model of psychosis, induced by psilocybin, a psychedelic with 5-HT2A/C agonistic properties, in healthy volunteers.

Methods

Twenty subjects (10M/10F) were given 0.26 mg/kg of psilocybin orally in a placebo-controlled, double-blind, cross-over design. ERPs (P300, MMN) were registered during the peak of intoxication. Correlations between measured electrophysiological variables and psilocin serum levels and neuropsychological effects were also analyzed.

Results

Psilocybin induced robust psychedelic effects and psychotic-like symptoms, decreased P300 amplitude (p = 0.009) but did not affect the MMN. Psilocybin’s disruptive effect on P300 correlated with the intensity of the psychedelic state, which was dependent on the psilocin serum levels. We also observed a decrease in N100 amplitude (p = 0.039) in the P300 paradigm and a negative correlation between P300 and MMN amplitude (p = 0.014).

Conclusions

Even though pre-attentive cognition (MMN) was not affected, processing at the early perceptual level (N100) and in higher-order cognition (P300) was significantly disrupted by psilocybin. Our results have implications for the role of 5-HT2A receptors in altered information processing in psychosis and schizophrenia.

Bravermanová, A., Viktorinová, M., Tylš, F., Novák, T., Androvičová, R., Korčák, J., … & Vlček, P. (2018). Psilocybin disrupts sensory and higher order cognitive processing but not pre-attentive cognitive processing—study on P300 and mismatch negativity in healthy volunteers. Psychopharmacology, 1-13. 10.1007/s00213-017-4807-2
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The experience elicited by hallucinogens presents the highest similarity to dreaming within a large database of psychoactive substance reports

January 4, 2018 / LSD, Mushrooms / Psilocybin, Neuroscience, Papers, Psychology, Publications / By / ,

Abstract

Ever since the modern rediscovery of psychedelic substances by Western society, several authors have independently proposed that their effects bear a high resemblance to the dreams and dreamlike experiences occurring naturally during the sleep-wake cycle. Recent studies in humans have provided neurophysiological evidence supporting this hypothesis. However, a rigorous comparative analysis of the phenomenology (“what it feels like” to experience these states) is currently lacking. We investigated the semantic similarity between a large number of subjective reports of psychoactive substances and reports of high/low lucidity dreams, and found that the highest-ranking substance in terms of the similarity to high lucidity dreams was the serotonergic psychedelic lysergic acid diethylamide (LSD), whereas the highest-ranking in terms of the similarity to dreams of low lucidity were plants of the Datura genus, rich in deliriant tropane alkaloids.. Conversely, sedatives, stimulants, antipsychotics and antidepressants comprised most of the lowest-ranking substances. An analysis of the most frequent words in the subjective reports of dreams and hallucinogens revealed that terms associated with perception (“see”, “visual”, “face”, “reality”, “color”), emotion (“fear”), setting (“outside”, “inside”, “street”, “front”, “behind”) and relatives (“mom”, “dad”, “brother”, “parent”, “family”) were the most prevalent across both experiences. In summary, we applied novel quantitative analyses to a large volume of empirical data to confirm the hypothesis that, among all psychoactive substances, hallucinogen drugs elicit experiences with the highest semantic similarity to those of dreams. Our results and the associated methodological developments open the way to study the comparative phenomenology of different altered states of consciousness and its relationship with non-invasive measurements of brain physiology.
Tagliazucchi, E., & Sanz, C. (2018). The experience elicited by hallucinogens presents the highest similarity to dreaming within a large database of psychoactive substance reports. Frontiers in Neuroscience, 12, 7. 10.3389/fnins.2018.00007
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Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD

December 15, 2017 / LSD, Neuroscience, Papers, Psychology, Publications / By / , , , , ,

Abstract

Recent studies have started to elucidate the effects of lysergic acid diethylamide (LSD) on the human brain but the underlying dynamics are not yet fully understood. Here we used ‘connectome-harmonic decomposition’, a novel method to investigate the dynamical changes in brain states. We found that LSD alters the energy and the power of individual harmonic brain states in a frequency-selective manner. Remarkably, this leads to an expansion of the repertoire of active brain states, suggestive of a general re-organization of brain dynamics given the non-random increase in co-activation across frequencies. Interestingly, the frequency distribution of the active repertoire of brain states under LSD closely follows power-laws indicating a re-organization of the dynamics at the edge of criticality. Beyond the present findings, these methods open up for a better understanding of the complex brain dynamics in health and disease.
Atasoy, S., Roseman, L., Kaelen, M., Kringelbach, M. L., Deco, G., & Carhart-Harris, R. L. (2017). Connectome-harmonic decomposition of human brain activity reveals dynamical repertoire re-organization under LSD. Scientific reports, 7(1), 17661. 10.1038/s41598-017-17546-0
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Breaking the cycle of opioid use disorder with Ibogaine

December 7, 2017 / Iboga / Ibogaine, Neuroscience, Papers, Psychology, Publications, Substance Use Disorder / By /

Abstract

Ibogaine is an indole alkaloid that comes from the root of the West African shrub Tabernanthe iboga. Ibogaine has been used for centuries in spiritual celebrations, coming of age rituals, and healings among the Babongo and Mitsogo people of West Central Africa. In Africa today, approximately 2–3 million members of the Bwiti religion scattered in groups throughout the countries of the Gabon, Zaire, and the Cameroun take large doses for the “Bwiti initiation ritual”—a powerful “rebirth” ceremony that group members typically undergo before the commencement of their teenage years.
The discovery that ibogaine eliminates the signs and symptoms of opioid withdrawal and diminishes craving for opioids was first made in the 1960s by a group of self-treating individuals with heroin use disorder; a single oral dose administration of ibogaine was associated with a disruption of five addicted individual’s use of opiates for up to 6 months . An underground railroad of individuals in recovery helping others with addictions arose, using ibogaine to help people break their cycle of addiction to heroin, cocaine, and alcohol. Ibogaine is thought to enable individuals with opioid use disorder to transition to abstinence and establish a substance-free recovery through an ibogaine-induced experience that has personal meaning and/or other benefits. Ibogaine’s long-lasting metabolite noribogaine may reset brain circuits to block the intractable cravings and desire to use opioids that set the addiction relapse cycle into motion.
C. Mash, D. (2017). Breaking the cycle of opioid use disorder with Ibogaine. The American Journal of Drug and Alcohol Abuse, 1-3. 10.1080/00952990.2017.1357184
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The serotonin hallucinogen 5-MeO-DMT alters cortico-thalamic activity in freely moving mice: Regionally-selective involvement of 5-HT1A and 5-HT2A receptors

December 6, 2017 / Depressive Disorders, Neuroscience, Papers, Psychology, Publications / By / , , ,

Abstract

5-MeO-DMT is a natural hallucinogen acting as serotonin 5-HT1A/5-HT2A receptor agonist. Its ability to evoke hallucinations could be used to study the neurobiology of psychotic symptoms and to identify new treatment targets. Moreover, recent studies revealed the therapeutic potential of serotonin hallucinogens in treating mood and anxiety disorders. Our previous results in anesthetized animals show that 5-MeO-DMT alters cortical activity via 5-HT1A and 5-HT2A receptors. Here, we examined 5-MeO-DMT effects on oscillatory activity in prefrontal (PFC) and visual (V1) cortices, and in mediodorsal thalamus (MD) of freely-moving wild-type (WT) and 5-HT2A-R knockout (KO2A) mice. We performed local field potential multi-recordings evaluating the power at different frequency bands and coherence between areas. We also examined the prevention of 5-MeO-DMT effects by the 5-HT1A-R antagonist WAY-100635. 5-MeO-DMT affected oscillatory activity more in cortical than in thalamic areas. More marked effects were observed in delta power in V1 of KO2A mice. 5-MeO-DMT increased beta band coherence between all examined areas. In KO2A mice, WAY100635 prevented most of 5-MeO-DMT effects on oscillatory activity. The present results indicate that hallucinatory activity of 5-MeO-DMT is likely mediated by simultaneous alteration of prefrontal and visual activities. The prevention of these effects by WAY-100635 in KO2A mice supports the potential usefulness of 5-HT1A receptor antagonists to treat visual hallucinations. 5-MeO-DMT effects on PFC theta activity and cortico-thalamic coherence may be related to its antidepressant activity.
Riga, M. S., Lladó-Pelfort, L., Artigas, F., & Celada, P. (2017). The serotonin hallucinogen 5-MeO-DMT alters cortico-thalamic activity in freely moving mice: Regionally-selective involvement of 5-HT 1A and 5-HT 2A receptors. Neuropharmacology. 10.1016/j.neuropharm.2017.11.049

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Ketamine and pharmacological imaging: use of functional magnetic resonance imaging to evaluate mechanisms of action

November 30, 2017 / Depressive Disorders, Ketamine, Neuroscience, Papers, Psychology, Psychotic Disorders, Publications / By / , ,

Abstract

Ketamine has been used as a pharmacological model for schizophrenia as subanesthetic infusions have been shown to produce temporary schizophrenia-like symptoms in healthy humans. More recently, ketamine has emerged as a potential treatment for multiple psychiatric disorders, including treatment-resistant depression and suicidal ideation. However, the mechanisms underlying both the psychotomimetic and the therapeutic effects of ketamine remain poorly understood. This review provides an overview of what is known of the neural mechanisms underlying the effects of ketamine and details what functional MRI studies have yielded at a systems level focused on brain circuitry. Multiple analytic approaches show that ketamine exerts robust and consistent effects at the whole-brain level. These effects are highly conserved across human and nonhuman primates, validating the use of nonhuman primate models for further investigations with ketamine. Regional analysis of brain functional connectivity suggests that the therapeutic potential of ketamine may be derived from a strengthening of executive control circuitry, making it an intriguing candidate for the treatment of drug abuse. There are still important questions about the mechanism of action and the therapeutic potential of ketamine that can be addressed using appropriate functional neuroimaging techniques.
Maltbie, E. A., Kaundinya, G. S., & Howell, L. L. (2017). Ketamine and pharmacological imaging: use of functional magnetic resonance imaging to evaluate mechanisms of action. Behavioural Pharmacology, 28(8), 610-622. 10.1097/FBP.0000000000000354
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TrkB dependent adult hippocampal progenitor differentiation mediates sustained ketamine antidepressant response

November 21, 2017 / Depressive Disorders, Ketamine, Neuroscience, Papers, Publications / By / , , , , , ,

Abstract

Adult neurogenesis persists in the rodent dentate gyrus and is stimulated by chronic treatment with conventional antidepressants through BDNF/TrkB signaling. Ketamine in low doses produces both rapid and sustained antidepressant effects in patients. Previous studies have shed light on post-transcriptional synaptic NMDAR mediated mechanisms underlying the acute effect, but how ketamine acts at the cellular level to sustain this anti-depressive function for prolonged periods remains unclear. Here we report that ketamine accelerates differentiation of doublecortin-positive adult hippocampal neural progenitors into functionally mature neurons. This process requires TrkB-dependent ERK pathway activation. Genetic ablation of TrkB in neural stem/progenitor cells, or pharmacologic disruption of ERK signaling, or inhibition of adult neurogenesis, each blocks the ketamine-induced behavioral responses. Conversely, enhanced ERK activity via Nf1 gene deletion extends the response and rescues both neurogenic and behavioral deficits in mice lacking TrkB. Thus, TrkB-dependent neuronal differentiation is involved in the sustained antidepressant effects of ketamine.
Ma, Z., Zang, T., Birnbaum, S. G., Wang, Z., Johnson, J. E., Zhang, C. L., & Parada, L. F. (2017). TrkB dependent adult hippocampal progenitor differentiation mediates sustained ketamine antidepressant response. Nature communications, 8(1), 1668. 10.1038/s41467-017-01709-8
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