Neurulation is defined as a series of morphogenetic movements that result in the formation of the neural tube, a dorsal hollow nerve cord that constitutes the rudiment of the entire adult central nervous system. Knowledge of the mechanisms of secondary neurulation are essential, given the high incidence of human posterior spinal cord malformations. However, despite decades of research, the cellular and genetic basis for this type of neurulation remains poorly understood. The Brewster laboratory uses the advanced genetic tools and labeling techniques available in the zebrafish, to investigate the mechanisms underlying secondary neurulation. These studies will ultimately increase our understanding of how neurulation is orchestrated and provide a molecular basis for exploring the etiology of posterior neural tube defects in humans