BDNF and Anxiety: Through the examination of brain-derived neurotrophic factor (BDNF) that has been considered as the critical regulator associated with stress, fear, and anxiety [43], a change in amygdalar BDNF levels in the HFD-saline and chow-LPS groups was not evident, although its level was significantly reduced in the ACC of the three animal groups (HFD-saline, chow-LPS, and HFD-LPS) compared to that observed in the control group (Fig. S5).