The immunohistochemical reaction of caspase 3 stained sections (X 400): (A) control group showing immune-positive cells with cytoplasmic reaction located mainly in zona granulosa and dispersed throughout zona fasciculata. (B) Control exercise group showing mild increase of the caspase3 positive cells in both zona glomerulosa and zona fasciculata. (C) Depression group showing extensive increase in the caspase3 positive cells in the zona granulosa, and aggregates of the immune-positive cells throughout the zona fasciculata (thick arrows). (D) Depression exercise group showing obvious reduction of immunoreactive cells in comparison to the depression group. The cells showed intense reaction and are dispersed in the zona glomerulosa and zona fasciculata (E) The mean numbers % of caspase 3 positive cells in different groups. Note: ZG, zona granulosa; and ZF, zona fasciculata.