Cognitive dysfunction and dementia in animal models of hypertension

Abstract

Since decades, epidemiological data have shown a high prevalence of hypertension (HT) in vascular dementia (VaD) and Alzheimer’s disease (AD). However, while antihypertensive treatments show a clear protective effect against stroke-related cognitive impairments, their beneficial effects against mild cognitive impairment (MCI) or other forms of dementia remain to be clearly established. Structural and functional vascular alterations in the brain are exposing the need for new experiments with validated animal models of HT in order to better understand the biological links between HT, cognitive impairment, and dementia. While most publications on dementia have focused on AD mouse models, a recent interest has emerged for a better understanding of the association between vascular diseases and cognition. Therefore, this chapter focuses on published data in animal models of HT related to cognitive dysfunction. The first part will present models of genetic HT such as spontaneously hypertensive rats (SHR) and Dahl saltsensitive rats (DS), and of HT induced by Angiotensin II (Ang II) and by transverse aortic constriction (TAC) in the context of cognitive functions. In the second part, we will discuss the consequences of HT on cerebrovascular function. Finally, we will review the potential benefits of antihypertensive drugs acting on the renin- angiotensin system (RAS) on cognitive deficits.