(A) Lixisenatide levels in the brains at 30 min following i.p. (2.5, 25 or 250 nmol/kg body weight) injection were increased. (B) Lixisenatide levels in the brains at 3 h following i.p. injection were only increased for the lower doses (2.5, 25 nmol/kg body weight). (C) The number of neuronal progenitor cells in the dentate gyrus was increased after 3 weeks of ip injection 25 nmol/kg bw once-daily. (D) The number of young neurons in the dentate gyrus was also increased. (E) The level of cAMP was enhanced in the brains after injection with 25 nmol/kg bw ip. (F) When directly comparing the effects of liraglutide with lixisenatide, a significant difference between drugs is found.* = p < 0.05, ** = p < 0.01. Micrographs: BrdU stain: A Saline control B Lixisenatide treated, 3 weeks once daily i.p. injection. Blue arrows point to BrdU positively stained cells. DCX stain: Doublecortin stained immature neurons in dentate gyrus. A Saline control B Lixisenatide treated, 3 weeks once daily i.p. administration.