High concentration of glucocorticoids in the hypothalamus exerts negative regulation of HPA axis.

<p>Depressive-like behaviors test were measured 28 d after infusion of CORT (10 µM, 1 µl) into each PVN: (A) Immobility time in the TST (n = 15 for each group). (B) Immobility time in the FST (n = 15 for each group). (C) Sucrose preference of mice (n = 15 for each group). (D) Locomotor activity of the mice within 5 min (n = 15 for each group). (E) Representative western blotting of CRF and GAPDH in the hypothalamus (left) and the statistical data of the western blotting experiment (right) (n = 4 for each group). Representative western blotting of CRF and GAPDH in the hypothalamus 28days after the infusion of 10 µM CORT (F) or 0.1 µM CORT into the PVN (H) and their statistical data (G, I), n = 4 for each group. Arrow heads indicate the location of nearest band in the ladder. (J) The concentration of CORT in the plasma 28 d after infusion. n = 4 for each group, the 10 µM CORT group and the 0.1 µM CORT were analyzed separately. Error bars denote SEM, *p<0.05, ***p<0.001, two-tailed Student's <i>t</i> test except for one-way ANOVA in (E).