Sensory neurogenesis depends on vascular-neuronal filopodia contacts and blood flow

Cranial sensory neurons develop in close proximity to blood vessels, however neurovascular interactions in the peripheral nervous system and their underlying signals are yet unknown. Here, we uncover two separate, novel roles for cranial vasculature in cranial sensory neurogenesis in zebrafish. The first involves precise spatiotemporal endothelial-neuroblast filopodial contacts and Dll4-Notch signaling to restrain neuroblast proliferation. Secondly, we find a role for signaling triggered by blood flow in promoting sensory neuron differentiation. Thus, we demonstrate that the cranial vasculature constitutes a hitherto unrecognized signaling component of the sensory ganglia niche and controls the pace of their growth and differentiation dynamics.