Stress-related mental illnesses like Post-Traumatic Stress Disorder (PTSD) and Major Depressive Disorder (MDD) are twice as common in women, but relevant pre-clinical research on the mechanisms of stress and fear has primarily been conducted in male animals. Our work explores the relationships between neural structure and function when both males and females experience aversive events, using behavioral and neuroanatomical techniques to identify sex-specific mechanisms of stress-induced plasticity.