FIGURE 2.

RISP model: Stage 1 (Pre-trauma classification): Rats are briefly stressed with a mild stressor (a ball of cat hair). Four days later, they are classified as Resilient (RES), Susceptible (SUS), or Intermediate (Int) based on their acoustic startle response (ASR1) and anxiety-like behavior in the Elevated Plus Maze (EPM); Stage 2 (Psychogenic trauma): Rats experience foot shock-motivated contextual fear conditioning (CFC) as a psychogenic trauma; Stage 3 (Post-trauma phenotype): Fear extinction and post-trauma startle (ASR2) are assessed. The original presentation of the model does not include other tests aligned with a complex PTSD-like phenotype, but these can be performed to evaluate cognitive and anxiety-like behavior after trauma. D = day; W = week.