Moderate treadmill exercise prevented anxiogenic behavior and impaired basal synaptic transmission in an Alzheimer's disease‐like rat model

Abstract

In this study, we investigated the effect of moderate treadmill exercise regimen on non‐cognitive function and basal synaptic transmission in AD‐like pathology model, achieved by i.c.v. infusion of Aβ1–42 (250 pmol/day) for 2 weeks. We have utilized a battery of behavioral tests to assess anxiogenic and exploratory behavior in adult Wistar rats treated with Aβ peptides and/or exercise training. Additionally, in vivo extracellular recording was used to evaluate changes in basal synaptic transmission in the Cornu Ammonis 1 (CA1) area. The animals were randomly assigned into 4 groups: control, exercise, Aβ infusion (Aβ) and Aβ‐infused/exercised (Ex/Aβ). Our data consistently indicated that Aβ rats showed increased anxiety‐like as tested in the open field, elevated plus maze, and light‐dark box paradigms. Interestingly, both Aβ and Ex/Aβ rats showed impaired locomotor activity compared to control and exercise rats. Hence, moderate treadmill exercise exerted an anxiolytic effect but failed to prevent locomotor deficits caused by AD. Additionally, the right shift of the I/O curve of Aβ rats indicated a markedly impaired basal synaptic transmission compared to those of other groups. Aβ rats also required a stronger stimulus to produce the same response at minimum, 30% of maximum, and maximum compared to other groups. Together, these data suggest a protective role of regular exercise in AD.