Space-time in Neural Development
Studying a population of neural progenitor cells in the mouse rhombencephalon, Pattyn et al. (Coordinated temporal and spatial control of motoneuron and serotonergic neuron generation from a common pool of CNS progenitors, Genes and Development, 17, 729-737, 2003) found that some homeobox genes act to couple spatial and temporal aspects of neural differentiation. In the rhombencephalon or ventral hindbrain, a population of progenitor neurons gives rise to visceral motoneurons. At a defined time, occurring about embryonic day 10 in the mouse, progenitors switch from visceral to 5-HT neuron production except for the cells in a segment of the area called “r4”.
A set of homeobox genes also important for the spatial patterning, is involved in this regulation. Further studies might show this mechanism in other regions of the central nervous system.