Looking across the literature, one sees widely divergent values for baseline mechanical, thermal and chemical pain behaviors. This prompts the question, is there an ‘average’ expected value? In some ways, I don’t want to know what is expected, since this influences how I perform my behavioral assays (even if subconsciously). If you have a control group, and you perform your assays in a consistent manner, the results are what they are. Nevertheless, having some working range to peg your own results to can help one to assess whether the assay is being performed correctly or if the test subjects truly are quite different than the average mouse.
@jmogil and others have shown that different strains have different basal pain sensitivities, but let’s take the most commonly used mouse, C57BL6/J, and share the typical expected values for various assays.
Von Frey Assay
Baseline anywhere from 0.4g to 1.0g
PWT = ~ 0.4g
Duan, B., Cheng, L., Bourane, S., Britz, O., Padilla, C., Garcia-Campmany, L., Krashes, M., Knowlton, W., Velasquez, T., Ren, X., et al. (2014). Identification of spinal circuits transmitting and gating mechanical pain. Cell 159, 1417–1432.
Significant Determinants of Mouse Pain Behaviour
PWT = ~0.6g
Xu, Z.-Z., Kim, Y.H., Bang, S., Zhang, Y., Berta, T., Wang, F., Oh, S.B., and Ji, R.-R. (2015). Inhibition of mechanical allodynia in neuropathic pain by TLR5-mediated A-fiber blockade. Nat Med 21, 1326–1331.
PWT = ~ 1.0g
… Will add more later.