I am planning to use the reversal learning paradigm as used for example by Ragozzino’s group (eg Palencia and Ragozzino 2006 Neuroscience). The habituation phase includes the exposure to the food reward, with which all 4 arms of the cross maze are baited. What would be the argument to do this instead of habituating the mice purely to the environment (letting them explore the maze without baiting the arms with food – but obviously exposing them to the food pellets in their homecage prior to the learning phase) before then baiting the goal arm during the learning phase?
My concern would be that by including food reward during the habituation phase I introduce an additional reversal learning condition whereby the mice learn that first there is food in every arm, then there is food in just one arm (before the ‘actual’ reversal where the mouse will have to figure out that the opposite arm to one that was baited during the learning phase is now the goal arm). Is this a valid concern?
I’d appreciate any opinion on that matter.
Thanks a lot
Nadine
Hi Nadine,
Giving food reward during the familiarization period becomes a model of on trial learning. This will affect the performance in reversal learnig. In my opinion in a plus maze or cross maze the reward should not be given during h abituation. The mice/rats can easily be made familiar to the maze without food during the habituation phase. And then there will be no problem with reversal learning. Plus maze learning ia a very simple paradigm and exposure of a single trial with food may cause learning to a great extent and the rats can easily recognize that arm in subsequent trials. I would suggest you to use a water maze instead.
Hi Nadine,
I think that during the habituation phase, the animal has to get familiarized with the apparatus, the environment and also with the clues: the rat has to know that there is a reward. Furthermore in most paradigms based on food reinforcement, the animals are food restrected prior testing so when you put the food in all arms you help the animal to learn that he will get food once he is in the apparatus and you give him more chance to eat.
HI Nadine,
YES! this is a very valid concern, and I have trained rats and mice in both ways. Good that you are paying attention to this. I have to agree with Arun here, no food reward during the habituation phase. But this will have some consequences. What is your question? Are you investigating OFC or mPFC in reversal learning, will you be moderating amounts of reward throughout training, or reversal learning? How important is +R to your question and the brain regions known to be involved in reinforcement? If you don't bait the arms during habituation, you still have to be sure the animal is exploring the environment completely, and sometimes they don't, then you introduce bias between amount of time the animal explores the environment prior to training, and may have dissimilar learning curves. If you are modeling your questions from previous work, use what has been previously used to answer your question. I assume you don't have a water maze. But check the literature on this (there is a lot!). In the end, as long as you are consistent you will be fine. Good luck!
- Badges
- Science topic
- Similar topics
- Medicine
- Disease
- Disease Models
- Animal Models
- Rodent Models
- Mouse Models