Behavioral characterization of ayahuasca treatment on Wistar rats in the open field test

Abstract Ayahuasca (AYA) is a psychedelic beverage with therapeutic potential for many mood and anxiety disorders. Although there are some preclinical studies, no published reports have tested the behavioral effects of AYA gavage in animal models. This investigation aimed to characterize the behavior of Wistar rats after acute ingestion of AYA for 40 min in the open field test (OFT). The sample consisted of three experimental groups treated with different dosages of AYA (125, 250, or 500 mg kg-1) and a control group. Each group consisted of 10 participants. After gavage, the number of crossings of the OFT grid lines, latency to enter the central area of the device, grooming frequency, and time spent in the central perimeter of the device were immediately evaluated. Analyses were based on one-way ANOVA and a linear-regression mixture model for longitudinal data. AYA intake did not interfere with habituation. The 500 mg kg-1 group showed a decrease in the time spent in the center of the device and in the number of crossings compared to the control group in the last 10 min. These results suggest that gavage with AYA did not interfere with the results, and the behavioral effects were perceived only between 30 and 40 min after gavage. Taken together, the results indicate that three aspects should be considered in OFT studies of AYA acute effects: the moment when the observation starts, the observation period, and the AYA dosage.

BDNF Val66Met polymorphism and resilience in major depressive disorder: the impact of cognitive psychotherapy

Objective: Clinical and biological correlates of resilience in major depressive disorder are scarce. We aimed to investigate the effect of the Val66Met polymorphism in the BDNF gene on resilience scores in major depressive disorder patients and evaluate the polymorphism's moderation effect on resilience scores in response to cognitive therapy. Method: A total of 106 major depressive disorder patients were enrolled in this clinical randomized study. The Resilience Scale and the Hamilton Rating Scale for Depression were applied at baseline, post-treatment, and at six months of follow-up. Blood samples were obtained at baseline for molecular analysis. Results: The baseline resilience scores were higher in patients with the Met allele (114.6±17.6) than in those with the Val/Val genotype (104.04±21.05; p = 0.037). Cognitive therapy treatment increased resilience scores (p ≤ 0.001) and decreased depressive symptoms (p ≤ 0.001). In the mixed-effect model, the Val/Val genotype represented a decrease in resilience scores (t218 = -1.98; p = 0.048), and the Val66Met polymorphism interacted with sex to predict an increase in total resilience scores during cognitive treatment (t218 = 2.69; p = 0.008). Conclusion: Our results indicate that cognitive therapy intervention could improve resilience in follow-up, considering that gender and genetic susceptibility are predicted by the Val66Met polymorphism.