BDNF and memory impairment: Notwithstanding evidence showing that acute or chronic stress decreased BDNF expression, which could lead to the loss of synaptic function and increased vulnerability to insults [25,26], other studies reported BDNF overexpression resulting in memory impairments in the forebrain of mice [27], as well as in the hippocampus, hypothalamus, and pituitary gland in chronically stressed rats [28].