NRG1 and schizophrenia: The NRG1 gene, identified as a schizophrenia susceptibility gene [as reviewed in Rossignol, 2011; Marin, 2012], is subject to alternative splicing (Falls, 2003), resulting in the expression of two distinct protein isoforms in the developing telencephalon: Nrg1-Ig, a diffusible protein expressed in the pallium, and Nrg1-CRD, a membrane-bound protein expressed along the dorsal migratory streams, which, respectively, act as long- and short-range attractors for MGE-derived INs.