Neurosensory Specification and Development

During development, generalized ectoderm is in a stepwise fashion restricted in its transformative potential to a specific cell fate within a functional unit of the future brain. To achieve this, these cells are first primed, then committed to a defined lineage, and eventually induced to differentiate into a large variety of distinct neuronal and sensory cell types of the brain, the peripheral nervous system, and the major sensory organs. This process entails an initial suppression of the generalized ectodermal fate concomitant with acquisition of a new fate. The presumptive neurosensory cells are then committed to differentiate into distinct cell types that are dependent on regionalized signals relayed to them from other parts of the brain through specific connections, including unique sets of receptors and transmitters. The current understanding of some of the molecules involved in this process is reviewed for neurosensory development, one of the processes better understood at the molecular level.