Spindler's Mice - More Details

[Guest guest]

Hi folks:

The salient facts about Spindler's mice have already been posted I

think. But there are some relatively minor details that are also

worth noting. Here is one that may support Francesca's view about

the desirability of edging into CR gradually:

Spindler's mice were phased into CR in two stages. First 25% CR for

two weeks (eighteen months in human terms). Then ~50% CR

thereafter. But even with this gradual imposition of CR, the

mortality of the CR mice was initially slightly higher than for the

control mice. Indeed, in this study it wasn't until some time

between the third and fourth month of the experiment that the

cumulative mortality of the CR mice became lower than that of the

controls.

The difference during this period is small. It may merely be 'noise'

in the data, of no real significance - if the experiment were to be

exactly repeated it might turn out the other way around, because the

difference is small.

However, four months in the life of a mouse is about equivalent to

thirteen years in human terms. Perhaps not a little detail if the

difference in mortality rates is real - that is, not just 'noise'.

My guess is that there is no way to tell if it is noise or not

without exactly repeating the experiment, probably more than once.

Rodney.