Furthermore, the antagonist reduced the serum levels of CORT and increased BDNF, PSD95, synaptophysin (SYP), and MAP2 in the hippocampus of rats with depression, suggesting that the antidepressant-like effects of Ro41-5253 in depressed rats improve the hyperactivity of the HPA axis and hippocampal neuronal dysfunction [49]. Here, BDNF is linked to major depressive disorder.