Furthermore, our results demonstrate also that the genetic background plays a key role in the regulation of BDNF/trkB signaling under basal conditions and after acute stress; thus, the same acute stressor impacts in opposite directions on BDNF/trkB transmission in the mesocorticolimbic system of depression-prone RLA rats and their depression-resilient RHA counterparts. The gene discussed is NTRK2; the disease is major depressive disorder.