Strain specific fear behaviour and glucocorticoid response to aversive events: modelling PTSD in mice.

"Pavlovian" fear conditioning in rodents allows studying the formation and extinction of fear memories. Male C57BL/6J but not BALB/c mice showed differential fear memory performance expressed as freezing and scanning behaviour for context and cue. Glucocorticoid stress hormones modulate the processing of fear-related stimuli. The augmented corticosterone response of BALB/c mice to conditioning and testing, therefore, might have contributed to the strain-dependent formation of fear memories. We propose that modulation of extinction processes by glucocorticoids can be relevant in modelling anxiety disorders.