Are there behavioral tests that can be performed to assess learning and memory in rodents, that are independent of sensory cues? How can one say with certainty that hippocampal learning is compromised without alterations in the somatosensory or visual or olfactory input pathways?
Those tests do not exist. I do understand your why you ask the question and it is a very important issue. One should always do proper control experiments to exclude the possibility that the deficit is not caused by changes in perception or motor skills.
For example, in case of the water maze the visual version is quite a good control experiment. If the hidden platform is clearly marked with a visual cue and both groups reach it with the same latency than it is most likely that there visual and motor systems are equally good.
For fear conditioning it is not so easy. You can test if animals can freeze at all by increasing the amount of shocks until you get a ceiling effect when they almost 100%. This should not differ between groups. You could also test their sensitivity via a heat plate or von Frey test. Although one might argue that these tests possibly do not measure the same sensory input as needed for feeling the shock. Finding a way to quantify the reaction to the shock, number of jumps, vocalizations or distance traveled for example, would also give an indication if the shock is perceived similarly. Freezing immediately after the shock in the training trial also serves as a control. If that is similar between groups but the memory test isn't you can be more confident that is due to memory and not sensory problems.
I can highly recommend the book. 'what's wrong with my mouse?' Article What''s Wrong with My Mouse
Are there any specific tests you want to apply? and do you have any reason to assume that one group might have sensory issues?
best
Nils
Thank you very much Nils Borgesius for your answer. My animals do show impaired learning in the NOR, but also showed deficits in odour discrimination. I was wondering if this could confound my NOR results. I haven't tested my animals for texture discrimination yet. Please let me know if there are good tests for it.
Sorry, I have almost no experience with NOR. I think people usually try to rule out ofour as a factor as much as possible by cleaning everything with 70% ethanol. In any case it is always better to use more than one approach to show anything experimentally. Be it multiple shRNA constructs and a dominant negative protein in a cell culture or morecthan one test for memory. If you can, add another memory test.
- Badges
- Science topic
- Similar topics
- Biological Science
- Zoology
- Mammalogy
- Suckling Animals
- Eutheria
- Rodentia