Dear Mohammad Mosaferi Ziaaldini,

Probably, because in these studies the mices/rats are induced to do the exercises, as you mentioned, during the phase that they are less active.

It is an interesting question to be researched, don't you think?

Nocturnal species do not behave as diurnal ones of course

You may find this paper of interest with regard to your question. I hope so

Best

Hi Mohammad,

Light cycle and time of day are very important factors to consider in any sort of rodent exercise study. Many researchers use reverse light cycles where the rodent's dark period corresponds to the typical work day. In addition to differences between activity levels in the light and dark periods, the length of these periods (day length) can significantly affect activity patterns and overall levels.

Thanks Benjamin,

So, In your opinion, in order to study effect of exercise training in mice and rat, it would better to dawn at evening or night. is it right?

Best,

Thanks dear Touitou ,

It must be useful. I am reading it.

Thanks

Dear Pedro ,

I am in agree with you.

actually, because theoretically circadian rhythm regulate some important hormones secretion, so I think it is critical for researcher to distinct effect of exercise training and circadian rhythm..

Hi Mohammad,

Valid and awesome question, I always wondered about these things...

Circadian rhythms influence on everything after all...

As we would expect, the behavior in the lab differs to a great extent from the behavior in the natural environment. Even a phase-shift can occur, when a nocturnal animal becomes diurnal under lab conditions. I think comparing field and lab approach to understand which variables shape activity patterns is a way to go - The attached thesis provide some insights and relevant citations to the matter

For animals in general, it is sooo important to note that temporal niche is not that well-determined, instead some display high plasticity, and many other factors (besides light and temperature) affect timing of activity patterns, such as prey availability and food intake, predation risk, social interaction, habitat structure (vegetation and a reef complexity for instance) etc ect...

It is an emerging field that have implications both for medicine and for conservation [as surveys restricted to daylight hours might misrepresent the state and ecology of a species, which is excitingly the focus of my current research project]

In short, I do believe circadian rhythms is a important factor when using an animal model and with all the known and unknown variables, it is very challenging to measure the reliability of these studies, but definitely something to account for.

Dear Isabella,

Thank you!

Yes, the circadian rhythm is an important factor when using night-active animals.

As an adequate approach to study mice and rats, I recommend to use an inverted lighting regimen (12 hours dark/12 hours light), and dim red light during the dark phase to facilitate experimenters' activities. This will supply ground to compare results obtained during active phases in nocturnal species with those in diurnal animals and humans.