Science Buddies: "Ask an Expert"

Hello, I am a 12th grader and I am doing a science fair project on the circadian rhythm of a guinea pig. I want to observe her sleep and activity levels. Then, I want to manipulate her circadian rhythm by changing her diet, feeding times, and playing times. I would like to know which vegetables would be the best to feed her in order to manipulate her sleeping patterns and or activity levels. I currently feed her carrots, celery, and cabbage.

Thank you

Hi,

Circadian rhythms are especially interesting as they apply to both humans and other animals such as guinea pigs and even cats and dogs. Flying to a country more than a few time zones away can disrupt our rhythms temporarily, but one of the best ways to reset our clocks is by adjusting our eating time to the new zone. I don't think it has so much to do with the type of food we eat as with the timing. I would continue feeding your pet what she likes to eat but at different times to see if that affects her activity rhythm. You could also try giving her doses of melatonin (available as a supplement) which is a hormone that regulates some circadian activities such as sleep. Just scale down the human dose by using a proportion factor based on weight.

Do you have more than one guinea pig? Results from experiments on a single subject cannot be analyzed statistically. If you do see an effect of treatment you can say there may be a trend but you can't prove it unless you do the same experiment with several animals and average the results. Scientists may do a pilot experiment with a couple of animals first to see if there is an effect, but a full study requires multiple animals and statistical analysis.

Let us know how you plan to measure changes in circadian rhythms and we'll try to help you to design the best experiments.

Good luck!

Sybee

Thank you so much for the suggestions! I will definitely be focusing on changing feeding times rather than finding different types of foods. I do have a couple more questions, will three test subjects be enough to run an experiment? My resources are limited. I also have a question about the acquiring data for activity levels. I was thinking of building a treadmill for the guinea pig and I was going to place a bike pedometer underneath to record distance. Does that sound like a good idea?

Thank You!

Hi,

Yes, we all know about trying to do science on a budget! But it can be done. Three animals is a good number and will allow you to do some statistical tests on the activity data. Try to use guinea pigs that are fairly close in age. I don't know if there's a gender difference, but you might want to use all females if you can get them.

I think your method of measuring activity is great! Just try to keep everything the same for each animal so that the only thing that is varied is the feeding time. You also said you wanted to look at play times but i would suggest that you just look at one variable at a time. If you usually play with them right after feeding then do that but otherwise be careful about changing there rhythms by playing with them at different times.

One other thing i thought of was is how will you know WHEN the animals are playing or napping? The pedometers will measure how much they exercise but not when. I use to have pet mice and I would sometimes hear them running in their wheel at 2 am!

One way you might be able to time their sleep and activity periods would be if you have a game or trail camera that detects motion and records still photos and video. Some cameras also have a time lapse setting where they will take a photo every so many minutes for a whole day. If you can borrow one of these cameras it would help you with determining when your animals are active. If you have a smart phone you could check the apps list and see if there's one for taking time-lapse or motion detection photos (https://play.google.com/store/apps/deta ... vity&hl=en)

Keep posting and we'll keep helping you get your study underway.

Good luck!

Sybee

Hi,

It looks like the other experts gave you some great advice, and your project sounds like fun! One piece of advice I would add in here is to not change more than one variable at once. I think that changing their feeding times is the best variable to change. You just have to keep in mind that if you change feeding times you have to keep what you are feeding them exactly the same for each animal and for every day. You also should not add the melatonin supplements to this experiment since you are already changing feeding times. That may be a good idea for a future research project.

Good luck with your project!

Thanks guys for all the help. As for the recording when they sleep and when the activities occur, I was planning to have a surveillance camera monitoring the animals at all times to view anything peculiar and to reference when they are being active or asleep. I am planning to use hamsters instead of guinea pigs based on the fact that hamsters are a lot cheaper. I am also noticing that guinea pigs do not really use the wheel a lot and are mostly stationary. I think hamsters will have higher activity levels and will utilize the wheel more. I have one question about the three test subjects. Should they have their own individual cages? Or should they be able to interact with one another?

Thanks Again!

That's a really good question. When we do mouse research we have 4 animals per cage, but we aren't doing behavioral studies. Are hamsters normally social critters? If so then isolation may cause behavioral changes. On the other hand if three animals share one cage then you have to mark them some way so that they can be distinguished on the video. Also, would you put three exercise wheels in one cage or just have one that they share?

I really don't have a good answer for your question. Hopefully the other experts can provide input on this and we can come up with a consensus about what would be the best method to do your experiment.

Good luck!

Sybee

http://jbr.sagepub.com/content/4/1/39.short

Hi -you might be able to decide on a good protocol for your experiment using hamsters if you review some of the papers found at the above site. There are several experiments - some investigating circadian rhythm in hamsters described.
Hope you can find some helpful information. If not in these papers, maybe others you can find that use hamsters for similar behavioral studies. It's always good to see how others went about setting up an experiment before you invest time and money into your project. See what problems may come up and how others solved them.

Good luck - behavioral studies are challenging but really fun and interesting!! Can't wait to see how you decide to set yours up.

Thank You! The website really helped me add more independent variables to my project. I want to control the wheel by locking it at certain times and only allowing the hamsters to use it at controlled increments of time. I will be putting each of the hamsters in identical individual cages with the same wheel, food bowl, water bottle, and bedding. I am choosing robo dwarf hamsters because they are very active and the fastest of the dwarf hamsters. They are also independent and can live alone.

My question today is, should the cages be next to each other? Or should I place each hamster in individual rooms? I looked at jbr.sagepub.com and I could not find any information about my questions.

Thanks again!

You need to keep all hamsters in the same environment. Don't want to introduce any new variables by changing rooms , light, temperature , etc
Maybe cages side by side but separated by a partition so they don't see each other?
I'm not sure - so maybe do some more research for the set up
Good luck.

Thanks for the help and tips. I am changing the type of hamster that I am using to female short haired hamsters. The robo dwarf hamsters are very small, tough to handle, and are hard to find a cage for. I have my material list and hopefully I can get stuff coming in so I can start my project.

Thanks,

Hello, I have hit a brick wall in my project planning. Since changing diet times, and activity times have been practiced by humans for the longest time, they are not the most innovative variables that I can test. I was just wondering if anyone had any good ideas to add to my procedure.

Thank you!

Did you research other variables you could test?
What are some other things that you think might have an affect on circadian rhythm?

Hi sisonrocky!

I agree with yvetteds that you should investigate some of the other factors that can potentially affect circadian rhythms to find alternate testing avenues. Off the top of my head, one thing you could look into (very relevant to today's sleep research as well) is the effect of bright lights--recently studies have been demonstrating how bright lights actually disturb normal circadian rhythms. Try to find some papers on this effect, and perhaps you can test it too! This would be very applicable to humans, since sleep deprivation can be augmented by looking at phones, screens with bright lights, etc. before bed.

Hope this helps! Keep researching and posting back with questions!
scibuddyAK

Thanks for the help guys. Sorry for the late reply, I've just been very busy and sick as of late. I am thinking about measuring the effects of red, and green lights on the hamsters. I really like the idea of the effects of bright light because most humans have phones and it is the last thing they look at before sleeping. Will try to research into the effects of light and I will try to find papers on it.

Thanks Again!

Sounds great! Thanks for checking back in. Let us know if you need any help with the papers!

scibuddyAK

Great idea to link to humans and computer use.
Research the blue light emitted from computers and the effects on humans to understand how important your project will be!
Good luck

Thanks! I do need help finding papers actually. I would really appreciate it if you guys could suggest credible sources for me to search papers on. I've been heavily relaying on http://www.ncbi.nlm.nih.gov/pubmed.

Thanks for suggesting the blue light! I am pretty sure that I could place an led light on the top of the hamsters' cages easily. I just need to do the research about the effect of these lights first.

Hello again, I have a concern that I need help with. I am wondering if three days of experimentation with different variables will be enough time to see changes in the circadian rhythm of the Syrian Hamsters?

Thank you

Hi - To answer your question "Is three days enough.....", I'd think about the data you will be collecting and think about how to make your data more reliable.
For example - If on day 1; the subjects are not showing any real changes since they are getting used to the change in the variable - how will this affect the overall data? We always want to have as many data points as possible to get a more reliable average. Will you use a graph to show the data points?
If you only have 3 data points and one is 'off' then the remaining 2 will not be sufficient to come to a conclusion.
Do a little more research on scientific method to understand the importance of sufficient data.

Good luck!

Hello!

Yes, I agree with the feedback given by yvetteds. Of course, different experimental situations call for different time intervals, but in your case I feel that 3 days would not allow for reliable analysis. Remember that a dataset has to be large enough to allow for analysis and reliable results. I'd suggest starting to test with a larger number of days, but as you go, try to notice trends, as you might need to reevaluate your initial plan if you're generating a lot of results/not very many.

Good luck!
scibuddyAK