I am doing Barnes maze on AD and control mice these days. The protocol we use is as followings:
1, Put the animal on the maze and the escape box for 1 minute respectively to reduce the stress before the training trial.
2, Put the animal in a black box in the middle of the maze for 1 minute every time before the trail, then hang up the box.
3, We have a 250 watt light hung above the maze and a buzzer beside.
4, Guide the animal to the escape box if he cant find it in 3 minutes.
5, 4 trials per day, continues for 4 days.
6, Probe test on the fifth day, to see how long the animal can find the escape box.
The problem is, our mice seem not afraid of the light or the noise. When they are guided to the hole connected to the escape box, they do not run into it. They even try to run out when put into the escape box. At the same time, almost no one run to the escape box by itself. Attachment is what apparatus we are using for the Barnes maze.
I guess our mice are not so sick of light or noise, since they are handled every other day in a bright and noisy hood. The other problem is that, the tube connect the hole and the escape box is so long, even longer than the mouse's body, that the animal can't touch the escape box and he has to fall down into it, which may makes him frighted.
Does anyone doing Barnes maze have the similar problem? Or does anyone have any suggestions for me?
I'm also thinking if it is reasonable to analyze the time the animals spend around the escape hole, since it seems impossible to get the data on the time they find the hole and get into the escape box.
Hi Yun,
I think you have made some relevant observations regarding the escape box. I'm not sure time around the escape hole is going to be informative, and even if it is, I can imagine reviewers would have issues with this. Try to make the escape box less fear inducing and more attractive. What about making some holes in it so that the mice can see where they are going? Maybe put some bedding in there as well? They definitely seem fearful of your current setup. Another option is to increase the aversiveness of the exposed environment by increasing the sound (or using a more relevant frequency?) and/or using a strobe light. The optimal solution would be to decrease the fearfulness towards the escape box while using standard conditions for the exposed environment.