Affect dysregulation and impulsivity are the main topics of neurobiological research in borderline personality disorder. Affect dysregulation subsumes enhanced resting arousal, increased emotional responsiveness as well as deficient emotional regulation and is associated with structural and functional abnormalities in a prefrontal-limbic network, above all orbitofrontal hypoactivity and amygdalar as well as insular hyperactivity. Impulsivity describes a lack of future-oriented problem solving style as well as a decreased threshold for motoric responses and is associated with decreased serotonergic activity in the ventral prefrontal cortex. Future research has to clarify how specific the findings of borderline personality disorder are and how far temperament dimensions, such as neuroticism can explain the neurobiological deviations from the norm.