Segmental specification of GABAergic inhibition during development of hindbrain neural networks

A primordial rhythm-generating neural network emerges during the segmental period of vertebrate hindbrain development, suggesting a common genetic bas is to both the structure and network activity of the region. We show here t hat segmentation influenced a postsegmental developmental step by which a G ABAergic rhythm generator was incorporated into the primordial network and increased rhythm frequency to near mature values. This process depended on specifications in r3 and r5 that controlled, on the basis of a two-segment repeat, later maturation of GABAergic inhibition.