More importantly, direct administration of 5-HT1BR agonist CP93129 or 5-HT4R agonist BIMU8 into the dCA1 via cannular infusion (Fig. 5j, k) significantly relieved the depressive behaviors in 3-month-old 5×FAD mice (Fig. 5l, m), and improved cognitive impairments in 6-month-old 5×FAD mice (Fig. 5n–q). The gene discussed is HTR4; the disease is Cognitive impairment.