Animal models of vascular dementia with emphasis on stroke-prone spontaneously hypertensive rats.

1. Two experimental models designed to reflect different aspects of vascular dementia (rats with cerebrovascular occlusion and rats with cerebral embolization) and stroke-prone spontaneously hypertensive rats (SHRSP) have been evaluated. The focus was on SHRSP as a model for vascular dementia. 2. Neuropathological data revealed that the cerebrovascular disorder in SHRSP was associated with lesions in their brains similar to those seen in typical human cases of multiple cerebral infarction. 3. SHRSP that died from cerebral infarction exhibited behavioural changes, including increased activity and disrupted circadian rhythms, which might correspond to the state of delirium observed in patients with dementia. 4. SHRSP displayed cognitive impairments in a step-through passive avoidance task. 5. When compared to age-matched Wistar Kyoto (WKY) rats, both conscious and anaesthetized SHRSP had significantly decreased cerebral spinal fluid (CSF) levels of acetylcholine (ACh). 6. These findings suggest that the SHRSP might serve as a suitable animal model for vascular dementia in humans caused by cerebrovascular lesions.