Acupuncture at PC6 acupoint up-regulates the expression of Tph1 gene and down-regulates the expression of Olr883 genes in rat brains, suggesting that the therapeutic effect of acupuncture for ischemic stroke may be closely related to the suppression of post-stroke depression and the regulation of olfactory transduction in middle cerebral artery occlusion rat model [20]. Here, TPH1 is linked to ischemic stroke.