The effect of electroconvulsive therapy on neuroinflammation, behavior and amyloid plaques in the 5xFAD mouse model of Alzheimer's disease

Microglial cells are affected in Alzheimer's disease (AD) and interact with amyloid-beta (Aβ) plaques. Apart from memory loss, depression is common in patients with AD. Electroconvulsive therapy (ECT) is an anti-depressive treatment that may stimulate microglia, induce neuroinflammation and alter the levels of soluble Aβ, but the effects of ECT on microglia and Aβ aggregation in AD are not known. We investigated the short- and long-term effects of ECT on neuroinflammation and Aβ accumulation. 5xFAD mice received either electroconvulsive stimulation (ECS n = 26) or sham treatment (n = 25) for 3 weeks. Microglia and Aβ were analyzed in samples collected 24 h, 5 weeks, or 9 weeks after the last treatment. Aβ plaques and microglia were quantified using immunohistochemistry. The concentration of soluble Aβ and cytokines was quantified using ELISA and levels of Aβ aggregates were measured with Western Blot. Microglial phagocytosis of Aβ in the hippocampus was evaluated by flow cytometry in Methoxy-X04 injected mice 24 h following the last ECS treatment. Y-maze and Elevated plus maze were performed to study behavior after 5 weeks. We could not detect any significant short- or long-term effects of ECS on Aβ pathology or neuroinflammation, but ECS reduced abnormal behavior in the Elevated Plus maze.