Wet or dry: translatable "water mazes" for mice and humans.

Although the cognitive and biological characteristics of Alzheimer's disease (AD) are well known and mouse models of AD are available, current treatments for AD-related cognitive deficits have quite limited efficacy. The development of tasks with cross-species validity may enable better prediction of the efficacy of potential new treatments. In this issue of the JCI, Possin et al. present a virtual version of the Morris water maze (a common test of spatial learning and memory for rodents) that is designed for use with humans. The authors tested a mouse model of AD (transgenic mice expressing human amyloid precursor protein [hAPP]) and patients in the earlier mild cognitive impairment (MCI) stage of AD in their respective versions of the maze. Using novel statistical methods, they detected similar deficits across species, providing support for the hAPP model and use of the virtual water maze. Importantly, this work enabled recommendations for appropriate sample sizes when developing potential therapeutics for AD.