Potentiation of antidepressant effects: NPY1R agonist and ketamine synergy enhances TrkB signaling and neurogenesis in the ventral hippocampus

Abstract

Background: Major Depressive Disorder (MDD) poses a significant challenge to global health, with current treatments often limited by efficacy and onset delays. This study explores the synergistic antidepressant-like effects of an NPY1R agonist and Ketamine, targeting their neurobiological interactions within the ventral hippocampus. Research Design and Methods: Utilizing a preclinical model, this study administered Neuropeptide Y receptor 1 (NPY1R) agonist and Ketamine, both separately and in combination, through intracerebroventricular (icv) and intranasal (i.n.) routes. The Forced Swimming Test (FST) was employed to assess antidepressant-like activity, while in situ Proximity Ligation Assay and immunohistochemistry were used to examine NPY1R/TrkB heteroreceptor complexes and BDNF expression in the ventral dentate gyrus (DG), along with neurogenesis markers. Results: The combined treatment significantly reduced immobility in the FST, indicative of enhanced antidepressant-like effects, correlated with increased formation of NPY1R/TrkB complex and brainderived neurotrophic factor (BDNF) expression in the ventral DG. These molecular alterations were associated with increased neurogenesis. Conclusions: The coadministration of an NPY1R agonist and Ketamine in a rodent model demonstrated potentiated antidepressant responses through synergistic neurobiological pathways, including TrkB signaling and hippocampal neurogenesis. This indicates a novel therapeutic strategy for MDD, warranting further clinical investigation to fully understand its implications.