Odor Influences Female Mouse Development and Life Span

Olfactory clues can be added to the many items that influence the highly plastic life span of short-lived species. You might recall that flies respond to the scent of food in ways that accelerate aging, while here researchers show that female odors slow development and extend life in female mice by 8% to 9%, give or take. This mechanism is one of many reasons as why one should be skeptical of any life span study in mice that shows effect sizes of much less than 20%, and was conducted in anything less than a very rigorous, controlled manner, with a large number of mice. The life span of short lived species is just very sensitive to environmental circumstances, as well as interventions that stimulate the same metabolic responses.

Several previous lines of research have suggested, indirectly, that mouse lifespan is particularly susceptible to endocrine or nutritional signals in the first few weeks of life, as tested by manipulations of litter size, growth hormone levels, or mutations with effects specifically on early-life growth rate. The pace of early development in mice can also be influenced by exposure of nursing and weanling mice to olfactory cues. In particular, odors of same-sex adult mice can in some circumstances delay maturation. We hypothesized that olfactory information might also have a sex-specific effect on lifespan.

We show here that the lifespan of female mice can be increased significantly by odors from adult females administered transiently, that is from 3 days until 60 days of age. The presence of odors from adult females produced an 8% increase in median lifespan of female mice, compared to the control group, and a 9% increase in the age at 90th percentile. Female lifespan was not modified by male odors, nor was male lifespan susceptible to odors from adults of either sex. Conditional deletion of the G protein Gαo in the olfactory system, which leads to impaired accessory olfactory system function and blunted reproductive priming responses to male odors in females, did not modify the effect of female odors on female lifespan.

Our data provide support for the idea that very young mice are susceptible to influences that can have long-lasting effects on health maintenance in later life, and provide a potential example of lifespan extension by olfactory cues in mice.

Link: https://doi.org/10.7554/eLife.84060