BDNF and post-traumatic stress disorder: Moreover, the present work examined whether the mPFC (e.g., Cg1, PrL, and IL), hippocampus (e.g., CA1, CA2, CA3, and DG), amygdala, and piriform cortex (PC) exhibited higher BDNF protein and BDNF mRNA expression for PTSD-like rats, and it also tested the connections among the mPFC (i.e., Cg1, PrL, and IL), hippocampus (i.e., CA1, CA2, CA3, and DG), amygdala, and PC by analyzing the data of BDNF or BDNF mRNA in the third retrieval session of situational reminder.