NPY and post-traumatic stress disorder: Few studies have observed the direct effects of BNST NPY manipulations and behavioral output as it relates to PTSD, although chronic restraint stress (discussed in detail below) has been shown to increase NPY expression in BNST in mice susceptible to stress-effects (DBA/2J mice; Pleil et al., 2012, 2015), suggesting an involvement in NPY activity after stressor exposure.