Comorbid Aβ toxicity and stroke: hippocampal atrophy, pathology, and cognitive deficit

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

“…The absence of a gross effect on MWT performance is not entirely surprising, given the highly motivating nature of this task (Moser, Moser, Forrest, Andersen, & Morris, 1995) as well as previous results reported from our group observing no differences in standard water maze performance using these brain manipulations (Amtul et al, 2014a). For example, on the mass training day in our previous study, when the platform was moved to a new location following four days of training to a single location, no differences were observed between groups.…”

“…Additionally, due to the high risk of stroke in the aged (Shi, Yang, Stubley, Day, & Simpkins, 2000;Vermeer, Longstreth, & Koudstaal, 2007) and AD population (Tolppanen et al, 2013), the altered disease severity and prognosis when stroke occurs in AD patients (Doraiswamy et al, 2002;Hachinski, 1979Hachinski, , 2011Snowdon et al, 1997;Song, Kim, Kim, Eah, & Lee, 2007), and the high incidence of mixed dementia with both vascular and AD pathology (Schneider, Arvanitakis, Bang, & Bennett, 2007), stroke has been posited as another factor that could contribute to the etiology and progression of AD. An earlier study in an animal model observed that a small stroke in the presence of elevated beta-amyloid increased infarct volume, inflammatory responses and disruptions in learning and memory processes, more so than when either factor was administered alone (Amtul et al, 2014a;Cechetto et al, 2008;Cheng et al, 2006;Whitehead et al, 2005aWhitehead et al, , 2007. The present study assessed the combination of beta-amyloid and stroke in order to identify alterations specific to learning and memory deficits as well as the effects of the combination of these factors on cholinergic status.…”

“…Therefore, stroke itself is damaging (Small, Morley, & Buchan, 1999), but when it occurs in combination with AD pathology, it will result in more damage and decreased cognitive function. To explore this theory in a rat model, stroke, specifically in the form of mild or mini-strokes, conducted in the presence of high levels of beta-amyloid produced larger infarct volumes, increased inflammation and memory loss more so than if only stroke or beta-amyloid were presented alone (Amtul et al, 2014a;Cechetto, Hachinski, & Whitehead, 2008;Whitehead, Cheng, Hachinski, & Cechetto, 2005aWhitehead, Hachinski, & Cechetto, 2005b). This model of a combination of factors that increases AD-like symptoms and pathology provides insight into the pathology associated with AD as well as the cognitive disruptions associated with AD and potential therapeutic targets and treatment options specific to the co-factors involved.…”

Part II: Strain- and sex-specific effects of adolescent exposure to THC on adult brain and behaviour: Variants of learning, anxiety and volumetric estimates

“…MWT training was done as described previously [52,53]. Rats were placed in the pool facing the wall and allowed 60 s to reach the submerged platform.…”

“…A similar apparatus and procedure was used as described previously [41,52,[54][55][56]. Two contexts were used that differ in shape, colour and odour.…”