As shown in Figure 3, ME-induced cerebral ischemia led to an obvious downregulation of BDNF protein level in the serum compared with sham group, whereas administration with 15, 30, 60, 120, and 240 mg/kg PNS for 14 days all attenuated ME-induced decrease of BDNF content. This evidence concerns the gene BDNF and brain ischemia.