Objective: 

It is known that stress can cause many diseases and affects hippocampus. While the effects of chronic stress on hippocampus are temporary in adults, in the adolescents where the brain development continues the effects are permanent. Oxytocin reduces anxiety and affects behavior. The aim of this study is to investigate the effects of chronic restraint stress on hippocampal cells in adolescence, and the role of oxytocin on these effects.

Methods: 

Thirty-eight days-old Wistar Albino rats of both sexes were used. Groups: chronic restraint stress+intranasal saline, chronic restraint stress+intranasal oxytocin (2mg/kg), control. Stress procedure; 1 hour/day for 7 days. On the 8th day, learning and memory test was evaluated with Morris' Water Maze. When rats were 50 days old, they were sacrificed and hippocampal VEGF and BDNF levels were evaluated with ELISA.

Results: 

It is shown that stress has adverse affects on learning process (females, p<0.004, p<0.001; males, p<0.05, p<0.004). Oxytocin treatment shortened the escape latency. (p<0.05, p<0.001 in females; p<0.05 in males). In probe trials, restraint stress group spent significantly less time in the target quadrant, more time in the opposite quadrant than other groups (p<0.002 for both sexes). Oxytocin treatment improved spatial memory in probe (p<0.001 for both sexes). VEGF and BDNF levels were increased in the oxytocin-applied groups compared to the others (females;VEGF,p<0.001,BDNF,p<0.05;males;VEGF,p<0.002,BDNF,p<0.05). Furthermore, positive correlation was found between VEGF and BDNF levels and the time spent in the target quadrant (r=0.533, p=0.002 with VEGF; r=0.434, p=0.017 with BDNF).

Conclusions: 

Results suggest that impaired hippocampal functions due to stress, can be affected positively by oxytocin.