Fig. 6. Age-related changes of GAD₆₇ message and protein levels in A1 and parietal cortex (PtA) of middle-aged and aged FBN rats compared to young adult rats. (A) Significant age-related changes in GAD₆₇ message levels were seen across all layers of A1 in middle-aged and aged FBN rats (except layer IV of middle-aged A1). Significant GAD₆₇ message decreases within PtA occurred only in the aged group. (B) Whereas all layers of middle-aged and aged A1 showed significant age-related decreases in GAD₆₇ protein, in PtA GAD₆₇ protein levels showed no age-related decreases except in layer IV of middle-aged and aged, and in middle-aged layer VI (^*P<0.05). (Modified from Ling et al., 2005.)