CREB1 and depressive disorder: Although PKA and p-CREB expression levels were upregulated following the treatment of acupuncture and fluoxetine, inhibition of PKA-CREB signaling by H89 reversed the upregulation of p-CREB expression level (but not PKA and CREB) and the antidepressant effects on ameliorating depression-related behaviors of acupuncture and fluoxetine, suggesting that both acupuncture and fluoxetine could achieve the antidepressant effects by promoting the phosphorylation of CREB on Ser133 by PKA-CREB signaling.