OPEN Foundation

F. Cruz

Ayahuasca blocks the reinstatement of methylphenidate-induced conditioned place preference in mice: behavioral and brain Fos expression evaluations


Rationale: Accumulating evidence suggests that ayahuasca, a hallucinogenic beverage used in traditional Amazonian communities for ritualistic and curative purposes, has been associated with reduced rates of substance use disorders. However, the brain mechanisms underlying the therapeutic effects of ayahuasca have not yet been fully elucidated.

Objectives: The aim of the present study was to investigate the effects of treatment with ayahuasca on the rewarding properties of the psychostimulant methylphenidate.

Methods: The rewarding properties of ayahuasca (100 mg/kg, orally) and methylphenidate (10 mg/kg, i.p.) were investigated using the conditioned place preference (CPP) model. Furthermore, we evaluated the effects of repeated treatment with ayahuasca on the reinstatement of methylphenidate-induced CPP. Fos expression was evaluated in different limbic structures (cingulate cortex-area 1, prelimbic cortex, infralimbic cortex, orbitofrontal cortex-lateral orbital area, nucleus accumbens core and shell, ventral tegmental area, dorsal striatum, and basolateral amygdala) upon each experimental phase.

Results: Both ayahuasca and methylphenidate induced CPP in mice. However, ayahuasca had limited effects on Fos expression, while methylphenidate altered Fos expression in several brain regions associated with the behavioral effects of drugs of abuse. Treatment with ayahuasca after conditioning with methylphenidate blocked the reinstatement of methylphenidate-induced CPP. Those behavioral effects were accompanied by changes in Fos expression patterns, with ayahuasca generally blocking the changes in Fos expression induced by conditioning with methylphenidate and/or reexposure to methylphenidate.

Conclusions: Our findings suggest that ayahuasca restored normal brain function in areas associated with the long-term expression of drug wanting/seeking in animals conditioned to methylphenidate.

Reis, H. S., Rodrigues, I., Anjos-Santos, A., Libarino-Santos, M., Serra, Y. A., Cata-Preta, E. G., Oliveira-Campos, D., Kisaki, N. D., Barros-Santos, T., Yokoyama, T. S., Cruz, F. C., Oliveira-Lima, A. J., Barbosa, P., Berro, L. F., & Marinho, E. (2020). Ayahuasca blocks the reinstatement of methylphenidate-induced conditioned place preference in mice: behavioral and brain Fos expression evaluations. Psychopharmacology, 237(11), 3269–3281.

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Toxicities Associated With NBOMe Ingestion—A Novel Class of Potent Hallucinogens: A Review of the Literature



A new class of synthetic hallucinogens called NBOMe has emerged as drugs of abuse.


Our aim was to conduct a systematic review of published reports of toxicities associated with NBOMe ingestion.


We searched PubMed for relevant English-language citations that described adverse effects from analytically confirmed human NBOMe ingestion. Demographic and clinical data were extracted.


A total of 10 citations met the criteria for inclusion, representing 20 individual patients. 25I-NBOMe was the most common analogue identified, followed by 25B-NBOMe and 25C-NBOMe. Fatalities were reported in 3 (15%) cases. Of all the patients, 7 (35%) were discharged after a period of observation, whereas 8 (40.0%) required admission to an intensive care unit. The most common adverse effects were agitation (85.0%), tachycardia (85.0%), and hypertension (65.0%). Seizures were reported in 8 (40.0%) patients. The most common abnormalities reported on laboratory tests were elevated level of creatinine kinase (45.0%), leukocytosis (25.0%), and hyperglycemia (20.0%).


NBOMe ingestion is associated with severe adverse effects. Clinicians need to have a high index of suspicion for NBOMe ingestion in patients reporting the recent use of hallucinogens.

Suzuki, J., Dekker, M. A., Valenti, E. S., Cruz, F. A. A., Correa, A. M., Poklis, J. L., & Poklis, A. (2014). Toxicities associated with NBOMe Ingestion, a Novel Class of Potent Hallucinogens: a Review of the Literature. Psychosomatics.
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27 June - Spiritual & Existential Dimensions in Psychedelic Care: Challenges & Insights