Interestingly, increasing evidence suggests that many of these genes affect lifespan by exerting their effects in a limited number of cell types and, in particular, neurons, indicating that the nervous system may be a central regulator of organismal lifespan. LinkOut Insulin-like signaling, metabolism, stress resistance and aging in Caenorhabditis elegans. The nervous system acts as a major regulator of the life span of Caenorhabditis elegans. Temperature and chemical stimuli from the environment are integrated with internal signals from the reproductive system to specify adult longevity. An insulin-like signaling cascade acts in neurons and coordinates control of senescence of the entire organism by regulating metabolism and a stress response mechanism.
Caloric restriction extends life span, possibly by activation of the stress response program.
Why only time will tell. The nematode Caenorhabditis elegans has become a model system for the study of the genetic basis of aging. In particular, many mutations that extend life span have been identified in this organism. The effect of a given mutation depends on a number of environmental and genetic conditions. For example, the combination of two mutations can result in additive, synergistic, subtractive, or epistatic effects on life span.