Behavioral and metabolic effects of escapable electric foot shock stress in male mice

The pathophysiology of post-traumatic stress disorder (PTSD) is not fully understood, prompting research using animal models. One of the approaches to induce PTSD-like traits in rodents involves exposure to unavoidable, unpredictable electric foot shocks. This study explored the effects of repeated electric foot shocks on behavior, hematology, and metabolic parameters in male C57BL/6J mice. The mice were subjected to 15 electrical stimuli (each 0.8 mA for 10 s, 10 s interval between sessions) in an electric foot shock apparatus featuring metal floor bars and two insulating bars for two consecutive days.

Stressed mice showed enhanced memory retention of fear, as evidenced by an increased number of freezing events in the aversive context test. In the elevated plus maze test, stressed mice spent significantly less time in the open arms, indicating anxious behavior. However, no significant behavioral differences were observed between the stressed and control groups in the open field test. Stressed mice had a larger hypothalamic mass, elevated liver lipid peroxide levels, and a higher red blood cell count, with no changes in total leukocyte count. Thus, escapable foot shock induces fear response, anxiety-like behavior and minor metabolic changes in mice.