BDNF and Alzheimer disease: HPLC results also showed that, compared with U + M pLXSN-EGFP and U + M + pLXSN-BDNF groups, the content of cerebral ACh in the U + M pLXSN-BDNF group significantly increased, suggesting that U + MpLXSN-BDNF displayed significant therapeutic effect on the AD rat model.