Psychopharmacology
July 16, 2020
Henrique Sousa Reis, Isa R. S. Rodrigues, Alexia Anjos-Santos et al.
21 citations
Ayahuasca, a hallucinogenic beverage used in traditional Amazonian rituals, blocked the reinstatement of methylphenidate-induced conditioned place preference in mice, indicating reduced drug-seeking behavior. Both ayahuasca (100 mg/kg, orally) and methylphenidate (10 mg/kg, i.p.) separately induced conditioned place preference. However, methylphenidate altered Fos expression in several limbic brain regions associated with drug abuse, while ayahuasca had limited effects on Fos expression. Treatment with ayahuasca after conditioning with methylphenidate prevented reinstatement of the conditioned place preference and generally blocked the changes in Fos expression induced by methylphenidate conditioning or reexposure. These findings suggest ayahuasca restored normal brain function in areas linked to long-term drug wanting or seeking.
Behavioural brain research
June 25, 2023
Rodolpho Pereira de Oliveira, Thais Yokoyama, Lucas de Santana Cardoso Thomaz et al.
2 citations
Activation of 5-HT2A receptors in the inferior colliculus (IC) by the agonist DOI reduces prepulse inhibition (PPI) of the acoustic startle in male Wistar rats, mimicking a schizophrenia-like deficit. A neural pathway connecting the IC and the pedunculopontine tegmental nucleus (PPTg) was identified. DOI injection decreased c-Fos-labeled cells in both the IC and PPTg, suggesting increased GABA activity. Blocking GABAA receptors in the PPTg with bicuculline prevented the PPI deficit caused by DOI in the IC. These findings indicate that IC 5-HT2A receptors help regulate inhibitory pathways mediating PPI, involving GABAergic transmission in the IC-PPTg circuit.
bioRxiv Preprint Server
May 7, 2024
Victor Distefano Wiltenburg, Gabriela Morales-Lima, Aline Valéria Sousa Santos et al.
preprint
Oral lyophilized ayahuasca, at doses equivalent to those used in traditional ceremonies, blocked the conditioned place preference (CPP) that mice normally develop for ethanol. In a CPP paradigm, mice pretreated with ayahuasca showed no preference for the ethanol-paired compartment (time difference within ±7 seconds), while controls showed a moderate preference (about +60 seconds). The effect was significant at all tested doses, and no differences were observed among ayahuasca groups. Ayahuasca was well tolerated at ceremony-equivalent doses, though the highest dose (5000 mg/kg) produced transient serotonergic-syndrome-like signs and locomotor deficits. ΔFosB expression in the nucleus accumbens did not differ among groups 24 hours after the post-test. The findings suggest ayahuasca may blunt ethanol-context preference, warranting replication with stronger reward baselines and additional molecular markers.