Development of the sensory nervous system in the vertebrate head: the importance of being on time

Sense organs and cranial sensory ganglia are functionally diverse, yet share a common developmental origin. They arise from a pool of multipotent progenitors and local signals gradually restrict their development potential to specify the inner ear, olfactory epithelium, lens and sensory neurons. This process requires the temporal integration of multiple signalling pathways, cross-repressive transcription factor interactions and tight coordination of cell fate specification and morphogenesis.