Repeated ayahuasca administration before and during social isolation prevented depressive-like behaviors and cortisol alterations in common marmosets. Animals given ayahuasca showed higher cortisol reactivity and fecal cortisol levels similar to family-group controls, no signs of anhedonia, and no increase in chronic stress-related behaviors, unlike isolated animals that received no intervention. The findings suggest ayahuasca promotes resilient responses and may have a prophylactic action against depression.
Marmosets, studied in their natural habitat using non-invasive fecal hormone measurements, are mainly monogamous, live in stable social groups with female competition and male cooperation, and form social bonds similar to humans, making them a potential model for social stress disorders. Laboratory studies confirm these behaviors and show sexually dimorphic responses to challenges influenced by age and social context. Their good adaptation to captivity, twin births, small size, and life cycle advantages have led to their use as animal models for psychiatric diseases like major depression. Juvenile marmosets have been used to develop a depression model and test Ayahuasca as an alternative treatment, with positive results encouraging further studies.
Chronic social isolation in marmosets leads to significant shrinkage of neurons in the striatum, a brain region that integrates emotion, motivation, and movement. Ayahuasca, a psychoactive plant-based brew, given before and during isolation, prevented this neuronal volume loss. The caudate and putamen of socially isolated animals treated with ayahuasca showed neuron sizes comparable to those of family-housed controls, while untreated isolated animals had markedly smaller neurons. The findings suggest ayahuasca may act as a prophylactic buffer against stress-induced structural brain changes.
Chronic stress from social isolation in juvenile male marmosets reduces neuronal volume in the somatosensory cortex, a brain region implicated in depression. Ayahuasca, a psychedelic brew, given before and during isolation prevented this reduction, with treated animals showing neuronal volumes similar to non-stressed controls. Trends also suggested preserved cortical structure, though differences in neuronal density and overall cortical volume were not statistically significant. These results indicate ayahuasca may protect against stress-induced cortical atrophy and support further research into its therapeutic potential for stress-related psychiatric disorders, especially in adolescents.