BDNF and Alzheimer disease: COX5A overexpression rescued the repression of the BDNF/ERK1/2 pathway, which is in line with the results presented in previous studies, thereby indicating that the BDNF/ERK1/2 pathway is a molecular therapeutic pathway in the treatment of cognitive impairment in Tg AD mice (Liu et al., 2013; Hou et al., 2010).