Mice grimace after vasectomiesCharles Choi4/28/12 4:30pmFiled to: ZoologybiologyVasectomiesMicePainScienceScitweetFb20EditPromoteShare to KinjaToggle Conversation toolsGo to permalinkBoth mice and men can find vasectomies a pain. That's what grimaces on the faces of the rodents suggest, thanks to our improved understanding of how rodents express pain.AdvertisementScientists want to better know when mice feel pain. There are animal welfare issues of not causing undue suffering, and scientific reasons as well — researchers would like to know when a therapy causes or relieves pain.Recently, scientists developed a way to measure pain called the Mouse Grimace Scale. Just as people grimace after getting hurt, so too do rodents have pained expressions — their eyes squint, their ears pull back, and their noses and cheeks bulge.AdvertisementTo see how well the scale works, investigators looked at mice who received vasectomies. Scientists apparently carry out the little snips on mice all the time, especially on genetically modified mice, presumably to control how they breed.As expected, mice apparently grimaced more after vasectomies. They also grimaced less when given painkillers. Science!!!The scientists detailed their findings online April 25 in the journal PLoS ONE.SponsoredImage credit: DJ Langford et al., Nature Methods.