Similarities between angiogenesis and neural development: what small animal models can tell us

During evolution vertebrates had to evolve in order to perform more and more complex tasks. To achieve this goal, they developed specialized tissues: a highly branched vascular system to ensure that all tissues receive adequate blood supply, and an intricate nervous system in which nerves branch to transmit electrical signals to peripheral organs. The development of both systems is tightly controlled by a series of developmental cues, which ensure the accomplishment of a complex and highly stereotyped mature network. Vessels and nerves use similar signals and principles to grow, differentiate, and navigate toward their final targets. Both systems share several molecular pathways, highlighting an important link between vascular biology and neuroscience. Moreover, the vascular and the nervous system crosstalk and, when deregulated, contribute to medically relevant diseases. This new phenomenon, named the neurovascular link, promises to accelerate the discovery of new pathogenetic insights and therapeutic strategies for the treatment of both vascular and neurological diseases. To study the development of both systems, scientists are taking advantage of the use of several vertebrate and invertebrate animal models. In the first part of this chapter, we will discuss the more commonly used animal models; in the second part, the striking similarities occurring during the development of the vascular and the neural systems will be revised.