Accelerated Aging: Animal Models

Animal models have been used to study accelerated aging, accelerated senescence, premature aging, premature senescence, and progeria-like syndromes. These models may be grouped into four classes: (1) experimentally induced models, (2) gene-modified models, (3) selection models, and (4) spontaneous models. There has been much debate over the connection between accelerated aging and disease status in animal models. Investigators interested in the basic mechanisms of normal aging have had to be prudent in their choice of animal models because early diseases leading to reduced life spans usually result from certain defects unrelated to mechanisms associated with normal aging, as suggested by David E. Harrison. In actuality, however, it is fairly difficult to discriminate between accelerated aging due to acceleration of the normal aging process and that due to the manifestation of diseases or pathologies. Thus, it might be important to check the pathologies or diseases an animal model manifests throughout its lifetime. In this context, species such as the nematode and fruit fly have disadvantages, in spite of their usefulness for genetic studies, because of a scarcity of information on diseases and pathologies.