Varenicline ameliorates learning and memory deficits in amyloid β(25-35) rat model of Alzheimer's disease

Introduction: alzheimer's disease (ad) is a enfeeble neurodegenerative disorder characterized by increased β-amyloid (aβ) deposition and neuronal dysfunction leading to impaired learning and recall. among proposed risk factors, impaired cholinergic transmission is a main cause for incidence of disease. methods: in the present study, effects of the intracerebroventricularly administration of an agonist of nicotinic cholinergic receptors, varenicline(0.5 and 2 μg/μl), on learning and memory impairments induced by intrahippocampal aβ(25-35) injection was assessed in rats. results: the results showed that the intrahippocampal aβ(25-35) injected rats exhibit lower spontaneous alternation score iny-maze tasks (p<0.05), impaired retention and recall capability in the passive avoidance test (p<0.05), and fewer correct choices (p<0.001) and more errors(p<0.001) in the ram task. varenicline, almost in both doses, significantly improved alternation score in y-maze task (p<0.001), impaired retention and recall capability in the passive avoidance test (p<0.05), and correct choices in the ram task (p<0.001). discussion: this study indicates that varenicline pretreatment attenuates aβ- induced impairment of short-term spatial memory in rats probably due to its agonist activity at nicotinic receptors.