What are your feelings regarding the controls for unilateral pain models such as inflammatory (CFA/Zymosan) or neuropathic (SNI)? Ipsi-Contra controls have the advantage of needing fewer subjects and also using the same mouse as its own control (within-subject), minimizing variability between subjects (potentially). The downside is that unilateral treatments might have contralateral effects, as some studies show. There isn’t consistency in this regard.
What do you think?
Mirror hypersensitivity is extremely common, and depending on the strain, extremely robust. I think it’s a big mistake to not have pre-injury baselines and (where appropriate) sham surgery groups.
Thanks @jmogil
I agree entirely with pre-injury baseline(s). And I’ve always done a sham or vehicle. But i see some studies in good journals sometimes using ipsi contra instead of sham. So I thought I’d ask.
I’d definitely be worried about “cross-over” effects, but I think how worried you should be depends on your model. If you’re modeling chronic pain, or looking in the brain, it’s likely a bigger issue than if you’re looking acutely in the periphery.