Animal models of cognitive dysfunction.

The increased life expectancy in industrialised countries in the last half century has also brought to a greater incidence of neurological disorders, including neurodegenerative diseases and developing in a rather long time. In this respect, Alzheimer's disease (AD), for the large incidence, and the dramatic loss of autonomy caused by its cognitive and behavioural symptoms represents one of the main challenges of modern medicine. Although AD is a typical human disease and probably includes several nosographic entities, the use of animal models may contribute to understand specific aspects of pathophysiology of the disease. The most widely used animal models are rodents and non-human primates. In this review different animal models characterised by impaired cognitive functions are analysed. None of the models available mimics exactly cognitive, behavioural, biochemical and histopathological abnormalities observed in neurological disorders characterised by cognitive impairment. However, partial reproduction of neuropathology and/or cognitive deficits of Alzheimer's disease (AD), vascular dementia and dementia occurring in Huntington's and Parkinson's diseases, or in other neurodegenerative disorders may represent a basis for understanding pathophysiological traits of these diseases and for contributing to their treatments.