Ketamine exerts antidepressant effects and reduces IL-1β and IL-6 levels in rat prefrontal cortex and hippocampus

Ketamine has fast-acting and robust antidepressant effects in animal models and depressed patients. It has been hypothesized that its underlying mechanism of action is associated with the inflammatory response in the central nervous system. Therefore, the present study was designed to investigate the antidepressant effects of ketamine and the expression of interleukin (IL)-1β and IL-6 in the prefrontal cortex and hippocampus of a rat model. Twenty Wistar rats were randomly divided into 2 groups (each group, n=10); the saline group and the ketamine group. On the 1st day, rats undertook a forced swimming test (FST) for 15 min (pre-test session). On the 2nd day, saline or ketamine was administered intraperitoneally 30 min before the test session. Following this, rats performed another FST for 5 min (test session) and the immobility time was recorded. The rats were then sacrificed, and the prefrontal cortex and hippocampus were harvested for determination of IL-1β and IL-6 levels. Compared with the saline group, ketamine administration significantly decreased the immobility time of rats during the FST (P<0.05). In addition, the ketamine group demonstrated a statistically significant decrease in the expression of IL-1β and IL-6 in rat prefrontal cortex and hippocampus compared with the saline group (P<0.05). Ketamine-induced antidepressant effects are associated with decreased levels of IL-1β and IL-6 in rat prefrontal cortex and hippocampus.