Altered microgliosis in Alzheimer's APP mouse brains. Microglial morphologies (marked by IBA1 antibody in red) including the process length, end-points and the number of microglia per neuritic plaque (marked by anti-Aβ 6E10 antibody in green) in 5xFAD or APP KI mice are differentially altered in response to BACE1 inhibition. 5xFAD mice had more dense, compact plaques with significant microglial contacts, while APP KI mice had more diffuse plaques with fewer microglial contacts. More plaque-associated microgliosis may remove more pre-formed plaques to reverse functional deficits like sleep dysfunction and epileptic seizures. For more information, see the article by Yao et al. (pages 6197–6211). Cover image: Xiangyou Hu.