Transient activation of the Notch-her15.1 axis plays an important role in the maturation of V2b interneurons.

In the vertebrate ventral spinal cord, p2 progenitors give rise to two interneuron subtypes: excitatory V2a interneurons and inhibitory V2b interneurons. In the differentiation of V2a and V2b cells, Notch signaling promotes V2b fate at the expense of V2a fate. Later, V2b cells extend axons along the ipsilateral side of the spinal cord and express the inhibitory transmitter GABA.