Animal Models and Ethics in the Testing of Drugs for Alzheimer’s Disease

In the last decade, dementia has been a major concern for both public and healthcare sectors, and Alzheimer’s disease (AD) is the biggest contributor to the rising number of dementias. Therefore, it is becoming mandatory to develop effective care and management strategies for dementia. Being a disease that manifests itself by behavioral changes and modifications in neuronal networks and physiology, it has always been a tricky choice to create suitable animal models. Classically higher mammals (nonhuman primates, or NHP) were preferred for the disease but that too raised serious ethical concerns. AD is the result of very complicated and still poorly understood complex pathophysiological changes, but there are some identified landmarks of this process such as amyloid precursor proteins (APP), presenilin 1 and 2 (PSEN1 and PSEN2), tau, etc. The mice models then started utilization of the tau protein, then came the models of secretase enzyme, the Aβ pathway, axonal transport models, and Apolipoprotein E (ApoE) models. Apart from rodents and NHPs, there were several other available and tested models in fruit flies and nematodes. This chapter discusses in detail the various types of models, their advantages, disadvantages, and ethical concerns related to them.