Long-term daily administration of ayahuasca to rats for 30 days did not affect their performance in the Morris water maze or elevated plus maze tasks. However, a dose of 120 mg/kg increased the contextual conditioned fear response for both background and foreground fear conditioning, while the tone-conditioned response remained unaffected. This heightened contextual fear response persisted across repeated sessions several weeks after training. These results indicate that long-term ayahuasca exposure can selectively enhance the contextual association of emotional events, consistent with the beverage's known activation of brain regions involved in emotional processing and memory.
Repeated daily ayahuasca administration over 30 days in male Wistar rats produced dose-dependent behavioral effects: a low dose (120 mg/kg) increased ambulation, while a very high dose (3600 mg/kg) decreased vertical exploration and reduced weight gain. The highest dose also increased c-Fos expression in the hippocampus and infralimbic cortex, indicating heightened neural activation in emotional processing and serotonergic pathways. The study does not support an anxiolytic effect of repeated ayahuasca in a novel anxiogenic environment but suggests low doses warrant further investigation. The absence of severe behavioral impairment reinforces ayahuasca's safety profile.
A reproducible five-day protocol for freeze-drying ayahuasca produces a stable extract with alkaloid concentrations similar to the original liquid. From two liters of ayahuasca, approximately 295 grams of freeze-dried extract were obtained, with a dry matter content of 14.75%. The freeze-dried extract retained its texture quality after three years of storage in a vacuum desiccator at about 6°C. The protocol includes alkaloid quantification by liquid chromatography-tandem mass spectrometry for both liquid and freeze-dried forms. Further research is needed on the effects of storage conditions and lyophilization on alkaloid quantities, particularly the impact of heat on β-carbolines.