Specification and regulation of the hypothalamic oxytocinergic system

The oxytocinergic and vasopressinergic systems regulate vital homeostatic functions as well as complex behaviors like social interaction. Despite their central neuromodulatory action, many details regarding the specification of the oxytocinergic and vasopressinergic circuits as well as the regulation of oxytocin (OXT) and vasopressin (AVP) release in the Central Nervous System remain unknown. Our laboratory has implemented a multidisciplinary approach combining genetic tagging for assaying OXT-containing vesicle dynamics and exocytosis, together with light-sheet ultraresolution microscopy and iDISCO+ tissue clarification methods for 3D circuit reconstruction (Madrigal & Jurado, 2021), in order to advance our current understanding of oxytocinergic and vasopressin function in modulating neuronal networks. We currently focus on analyzing the neurodevelopment of these systems and the dynamic properties of OXT and AVP release in the hypothalamus.Our results indicate a profound remodeling of the oxytocinergic and vasopressinergic systems during early postnatal stages that involves a switch of neuropeptide expression, which is recapitulated during vital experiences like aging or motherhood. Furthermore, OXT dynamics and release properties suggest distinct OXT-vesicle pools in the somatodendritic compartment of hypothalamic neurons which could be recruited upon diverse patterns of neuronal activity to orchestrate different aspects of behavior.