Discrimination between threatening and non-threatening experiences is adaptive for the individual, but sometimes trauma may cause a maladaptive shift toward generalization such as in PTSD. My dissertation will reveal novel brain pathways regulating discrimination in the rat, and how neurocircuit perturbations following a traumatic experience leads to memory over-generalization. Our leveraging of animal studies to identify maladaptive shifts in memory will make inroads for discovering better therapeutic interventions in stress-related psychiatric diseases in the future.