Rodent Routine

Each morning, I start my day by becoming an astronaut.

Or at least that’s what I look like after donning the extensive PPE required to enter Bryan Research’s basement mouse colony. I spend about 3 minutes donning a blue full body suit, shoe covers, a hairnet, a face mask, and gloves, for a trip into the mouse room that takes me 30 seconds. Nice. But it’s all so we don’t give the mice our nasty human diseases, which is pretty important. After collecting my six male mice (Fatboy Slim, Tarzan, Pavarotti, King Arthur, Charlie Chaplin, and Big Chunkus, aptly named based on their character), I head back upstairs to the Mooney lab to begin their experimental sessions.

For each of my 12 sessions (6 morning, 6 afternoon), I fill the chamber with either air or heliox and put one of my females in. After placing one of the males in the chamber, I start the webcam and the Spike2 microphone software to record their vocalizations and begin recording their mating behaviors every 10 seconds. When the session is over, I clean the chamber, change out the mice and hope I don’t get bitten, and begin the next session. It’s interesting, some mice are more sexually aggressive and have high proportions of rear sniffing and mounting, whereas some are more like nice guys who prefer to groom the female. Some are great vocalizers (eg. Pavarotti), and some are pretty silent (thanks Charlie Chaplin). All of their individual differences are eventually averaged by my trusty Matlab programs to create exciting sheets of data.

To turn sound files and Excel spreadsheets about behavior into usable data detailing mean pitch per behavior, amplitude per behavior, rate of vocalizing per behavior, and so much more, I start by importing the sound files. A 20 minute sound file takes about 45-50 minutes to convert into a Matlab file, so I import all 12 of the files into Matlab overnight. The next day, I’m able to find out the background noise of the files with the help of another Matlab program that generates spectograms, images of the sound file over a period of 10 seconds. I have to manually select periods of the spectogram where there’s no noise happening except the gentle hum of the air or heliox pumping in. This background noise plus the behavioral data I import gets reviewed by my final program that analyzes the vocalizations in the context of each behavior, subtracts out the background noise, and churns out all of the data I’ll need. After astronauticizing myself once more to return my tired males to the mouse colony, I set up the sound files for importing and breathe a sigh of relief.

That’s a typical day at the lab for me, although I’ve definitely had some bumps in the road. Once, I forgot to close Big Chunkus’ cage all the way after his session was finished. I went to retrieve him for his next session and saw he wasn’t in his cage. After panicking for a good 30 seconds and having the sudden realization that research buildings are probably crawling with lost mice, I opened his cage, only to find him clinging to the ceiling, munching on a pellet of food. I’ve also accidentally left my cage of females wide open, a field day for my particular batch of athletic and adventurous ladies who took the liberty of hopping out and exploring the desk around them. But I’m learning each day and can’t wait to see the final fruits of all this data analysis at the end of the summer and share it with you guys!

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