Neuroimmune regulation of behavior: Focus on sensory circumventricular organs and associated cell circuit mechanisms

Body-brain neuroimmune signaling is important for maintaining homeostasis and behavior. Dysregulation of these interoceptive communication pathways leads to compromised physical and mental health often associated with psychiatric disorders. Specialized interoceptive nodes considered as "gateways" to the brain offer an interface for communication with the periphery to aid in homeostatic maintenance and behavioral regulation. In this regard, sensory circumventricular organs (CVOs) with their strategic locations, fenestrated vasculature, and efferent neuronal projections, provide a unique opportunity for sensing and translating homeostatic and immune perturbations into adaptive behaviors. Despite their well-recognized role in homeostatic maintenance, mechanisms by which sensory CVOs detect and translate homeostatic and immune fluctuations into behavioral responses are not well understood. In this review, we attempt to discuss sensory CVO associated neuroimmune signaling and cell circuit mechanisms that regulate behaviors relevant to mental health.