Fig. 1

Ketamine decreases FST immobility in WKY and WIS rats without affecting locomotor activity. (A, B) Average day2 FST immobility for saline/ketamine treated WKY (n = 14–16/group) and WIS (n = 6–7/group) rats. Stress-susceptible WKYs exhibited dramatic baseline immobility compared to WIS controls (p < 0.0001). a Ketamine significantly decreased FST immobility in WKY rats at 30 min and 24 h after injection compared to saline (***p < 0.0001), with effects being comparable at 30 min and 24 h. b Ketamine also significantly decreased FST immobility in WIS rats at 30 min and 24 h after injection compared to saline (**p < 0.0073 and **p = 0.0063), with effects being comparable at 30 min and 24 h. c, d Average total distance travelled in the OFT for saline and ketamine treated WKY and WIS rats (n = 6/group). WKY rats exhibited less general locomotor activity compared to WIS controls (p < 0.0001). Ketamine had no effects on general locomotor activity at 30 min or 24 h post-injection in (c) WKY or (d) WIS rats. * vs. SAL; *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001