The reelin–nNOS connection should receive more experimental attention, as a number of reports indicate that alterations in reelin expression within the dentate gyrus may result in deficient maturation of newborn granule neurons and dampened hippocampal plasticity, and may represent a key event in the pathophysiology of depression (reviewed in Caruncho et al., 2016). This evidence concerns the gene NOS1 and depressive symptom measurement.