APP and Alzheimer disease: 2006). Thus, it is possible that the astrocytic APP mutation, at least in part, is involved in the synaptic dysfunction because the astrocyte creates a tripartite synapse. Therefore, we can conclude that the abnormality in synapse transmission is caused by mutant APP produced excessively in the aged astrocytes. Because the astrocytes are closely associated with neurons in the central nervous system, astrocytes are expected to influence the progressive cognitive deterioration in AD (Salmina 2009).