Effects of Estrogen Therapy on Cognitive Performance Deficit Induced by Nucleus Basalis Magnocellularis Lesion: Animal Model of Alzheimer's Disease

Cognitive performance appears to diminish with age and passing of time, probably due to the basal forebrain cholinergic dysfunction. Given the physiological significance of the acute effect of estrogen, this study was conducted aiming to investigate the effect of 17β-estradiol treatment on cognitive performance in nucleus basalis magnocellularis (NBM) induced lesions.
In this experimental study, 40 adult male Wistar rats were divided into five different groups (8 rat in each group): Control (intact), NBM lesion group, which received electrically-induced lesion (2 mA, 15s) in NBM, Sham group (the electrode was impaled into the NBM with no lesion), Estrogen group (lesionµg/kg 17β-estradiol) and Vehicle group (NBM lesion�µl sesame oil). Acquisition and retention testing was done using an eight-radial arm maze, in which, the patterns of arm entries in each group was recorded for calculating correct choices, working memory errors, reference memory errors and latency.
Findings: Bilateral NBM lesion showed the reduction of spatial memory acquisition in the form of increased working and reference memory errors (P 0.05).
Electrical NBM lesion can reduce spatial memory function. Estrogen therapy after brain injury improved cognitive disorder.