MAPK14 and Alzheimer disease: Additional evidence from preclinical murine models of AD show that these changes cause activation of other LTD-related pathways such as p38 mitogen-activated protein kinase (p38-MAPK) and glycogen synthase kinase 3 beta (GSK-3β) processes which ultimately lead to neurodegeneration (Figure 2, labels 11,12,13,14,16).