Rat Timer

A handy tool for behavioural work

Posted by Danny Schnitzler on January 09, 2021 · 3 mins read

A big component of my project is doing behavioural analysis. I look at anxiety-like behaviour in rats to compare how prenatal stress affects anxiety and stress. The two behavioural tests I have used so far are called an elevated plus maze and a light/ dark box.

Elevated Plus Maze

This test is a plus-shaped contraption that sits about two feet off the ground. Two of the arms have high walls, two of them are open. Rats like being in dark sheltered places, but they are also naturally curious. The more anxious they are, the less they will explore. I place the rat in the middle of the plus and use a camera on the ceiling to record where it goes, how often it enters the open or the closed arms, how much time it spends in each space, and how quickly it enters an open arm.

Light/ Dark Box

This is pretty much exactly what it sounds like – it is a box with a light side and a dark side. The dark side is completely black with a lid, and a little door frame. This leads to the other side of the box, which is clear plastic (the light side). Rat goes into the dark side, and I use a camera on the ceiling to record this little rat too. I measure the same things as above – how long it takes to enter the light side, how much time it spends in the light side, and how often it enters the light side.

Each rat is placed in this box or maze and allowed to roam around for 5-10 minutes. After that, the boxes need to be cleaned thoroughly so the next rat doesn’t get distracted by other rat smells.

So, after I spent months doing this with 160 different rats, I then went on to the analysis. The lab is supposed to have this fancy software that takes these video recordings and spits out the numbers I’m interested in. However, one quick look at these numbers told me they were all off. So, I had to sit down and analyse hours of video footage. And my star of a boyfriend came to the rescue. He is a software developer and he wrote me a simple programme to help me analyse the videos. He saved me hours of pausing, typing, and re-watching videos. Life saver. Relationship saver! Less time spent frustrated at rat videos, means more time doing fun things.

If you are interested in the rat timer, he put it on GitHub.