Comment by bitwize

Mouse models in papers like these mean they're using (live) mice to model human systems. They may even be altered or genetically engineered mice, which present problems of their own: for example Alzheimer's treatment candidates which work in mice that have been changed to have "Alzheimer's-like symptoms" rarely produce the same results in humans with actual Alzheimer's. But yes, in general an animal model is a cohort of live animals used to get a sense for what the effect would be like in humans.