Injection of specific amyloid-beta oligomers (beta1-40:Beta1-42510:1) into rat medial septum impairs memory retention without inducing hippocampal apoptosis

Abstract

Objectives: Because of the well-known neurochemical interactions between the septum and hippocampus during memory processes, we investigated the effect of amyloid-beta (A-beta) injection into the medial septum (MS) on the behavior in Wistar rats. We also assessed whether the observed effects were functional or due to apoptosis. Methods: Specific A-beta oligomers (beta1-40:beta1-42 510:1) were injected into MS for seven consecutive days. Behavior was assessed with the Morris water maze task. Results: Compared with the control group, rats that received A-beta oligomers exhibited significant memory retention impairment (P < 0.05) without apoptosis in the cornu ammonis (CA)1 and CA3 regions of the dorsal hippocampus. Discussion: These data indicate that septal injection of A-beta impairs memory retention, even in the absence of hippocampal apoptosis. This result might bring new insight to spatial memory-related disorders like Alzheimer's disease (AD). © W. S. Maney & Son Ltd 2013.