NMDA receptors coordinate brain vascular development via neuron-to-endothelial tip cell crosstalk in zebrafish

N-methyl-D-aspartate receptors (NMDARs) are a major class of glutamate receptors crucial for neural development and function. Here, we report that NMDARs expressed on neurons regulate brain vascular development via neurovascular communication. Dysfunction of neuronal NMDARs impairs the formation of the zebrafish brain vasculature and abrogates the neural activity-induced enhancement of the brain vascular development. These defects are attributed to the reduced growth of vascular endothelial tip cells (ETCs) situating at the leading edge of brain angiogenic sprouts. At the molecular level, NMDAR dysfunction down-regulates neuronal expression of vascular endothelial growth factor and subsequent global Ca²⁺ activities of ETCs, thereby impairing ETC growth. Thus, our study uncovers an important role of NMDARs in brain vascular development, expanding the functional repertoire of NMDARs and the mechanistic understanding of the interplay between nervous and vascular systems during development.