Co-morbid beta-amyloid toxicity and stroke produce impairments in an ambiguous context task in rats without any impairment in spatial working memory.

This study examined the combined effects of beta-amyloid administration and unilateral stroke in an animal model of AD. Adult rats were given a sham surgery, bilateral intraventricular infusion of 10μL of 50nmol Aβ25-35, a unilateral injection of endothelin-1 into the right striatum, or Aβ and endothelin-1 administration in combination. Following a recovery period, rats were tested in the 1-trial place learning variant of the Morris water task followed by an ambiguous discriminative fear-conditioning to context task. After behavioural assessment, rats were euthanized, and representative sections of the medial septum were analyzed for differences in choline-acetyltransferase (ChAT) immunohistochemistry. No differences were observed in spatial working memory, but the combined effect of Aβ and stroke resulted in deficits in the discriminative fear-conditioning to context task. A trend towards decreased ChAT-positive staining in the medial septum was observed. This study indicates that Aβ and stroke in combination produce worse functional consequences than when experienced alone, furthering the concept of AD as a disease with multiple and complex etiologies. PMID: 25576791 [PubMed - as supplied by publisher]
Source: Neurobiology of Learning and Memory - Category: Neurology Authors: Tags: Neurobiol Learn Mem Source Type: research