Psychogenic, neurogenic, and systemic stressor effects on plasma corticosterone and behavior: Mouse strain-dependent outcomes

The effects of several stressors were assessed in inbred strains of mice, B ALB/cByJ and C57BL/6ByJ, thought to be differentially reactive to stressors . Behavioral reactivity was greater in BALB/cByJ mice with respect to open- field emergence, step-down responding, response to a predator (rat) or to f ox urine odor. Neurogenic insults (e.g., footshock, forced swim, restraint) and a systemic stressor (intraperitoneal interleukin-1 beta treatment) lik ewise provoked a greater rise of plasma corticosterone in the BALB/cByJ mic e. Psychogenic stressors (e.g., novel open-field exposure. acoustic startle stimuli) also enhanced plasma corticosterone to a greater extent in BALB/c ByJ mice, but such an outcome was not apparent following predator-related c ues. It appears that whereas stressor reactivity and adrenal glucocorticoid release may be exaggerated in BALB/cByJ mice, such effects may be dependen t on the specific characteristic of the stressor situation.