Abstract: One of the central questions in developmental neurobiology is how a developing organism can generate a vast array of distinct neuronal cell types. For a terminally differentiating neuron this questions boils down to a gene regulatory problem that necessitates the decoding of the regulatory programs that instruct neurons to turn on neuron type-specific gene expression programs that characterize a postmitotic neuron. Through the decoding of cis-regulatory elements and forward genetic screen in C.elegans, my laboratory has begun to uncover what appears to some simple, phylogenetically conserved principles that may underlie the generation of neuronal diversity and that I will describe in this talk..