Acute footshock-stress increases spatial learning-memory and correlates to increased hippocampal BDNF and VEGF and cell numbers in adolescent male and female rats

It is well known that the acute-stress enhances cognitive functions in adults, but is not known in adolescents. The purpose of this study is to investigate the effects of low and high intensities of acute-stress on hippocampus and spatial memory in the adolescent male and female rats. Thirty-eight days aged rats were subjected to 0.2 and 1.6 mA intensity of footshock-stress for 20 min. Spatial memory performance was assessed in the Morris water maze. Learning had been positively affected in stress groups. Neuron density in the CA1 hippocampal region and the gyrus dentatus as well as VEGF and BDNF levels of hippocampus increased in all stress groups. In females, learning process and BDNF levels increased in low-intensity-stress group than high-intensity-stress group. There was no difference in hippocampal apoptosis among groups. We conclude that adolescent hippocampus is affected positively from acute-stress; however, while there is no difference in male response with respect to intensity of stress, females are affected more positively from low-intensity of stress. (C) 2012 Elsevier Ireland Ltd. All rights reserved.