Anxiety-like behavior is negatively correlated with amygdala volume. (A) Representative T2-weighted coronal MRI slices, which were registered to template. (B) Displays three-dimensional rendering views of atlas (left panel), lateral representative of brain (middle and right panel). Regional selections of mPFC and amygdala have shown red and green, respectively. (C–E) MRI volumetric measurements of whole brain, mPFC and amygdala, respectively. The horizontal bars represent mean values (as percent of brain volume). Data were analyzed by t-test (Control: n = 14, OVA: n = 17). (F) The number of entries to the open sections in elevated zero maze (inversely related to anxiety) was positively correlated with amygdala volume. ns, not significant; OVA, ovalbumin; mPFC, medical prefrontal cortex.