How and how long do you habituate animals for nociceptive assay testing?
In our lab, typically we bring the mice from the animal facility, either in their home cages or a transport vessel, and then put the mice in the testing apparatus, which consists of individual plexiglass containers on a mesh rack. We usually let the mice spend several hours (>2, although variable). We do this for two days, with no behavioral testing on those two habituation days. Then, on the third day, we bring the mice into the behavioral room as above, and let them habituate for at least two hours, which is about the time it takes for them to quiet down. Then we perform the VF assay. That measure is then the baseline measure.
Some people I’ve spoken to don’t do the multiple days of habituation before testing, and just test on the first day after a few hours of habituation to the room. Others whom I’ve spoken with say that they bring the mice into the room, let them get quiet (2-3 hours) and then perform VF assay over a series of days (2-3 days), taking the last day’s measure as the baseline. The reason for this multi-day testing is because the baseline value varies over time, becoming more constant as days go on.
What do you think?