“…Embryonic central nervous system (CNS) development is an ideal context in which to explore and understand the signals responsible for achieving the necessary target morphology. Developmental mispatterning is the cause of debilitating disorders, such as spina bifida (unclosed neural tube) (Copp andGreene, 2010, Detrait et al, 2005), anencephaly (small brain) (Copp and Greene, 2010, Detrait et al, 2005, Wallingford, 2006 and also increased susceptibility to degenerative disorders like Parkinson's, Alzheimer's, and autism (Doganli et al, 2013, Goldman et al, 2013, Pratt and Khakhalin, 2013. Hence, understanding how large-scale patterning of the brain normally occurs is a pre-requisite for major biomedical breakthroughs addressing birth defects and repairing injuries.…”