In APP/PS1 mice [160] harbouring the mutant human β-amyloid precursor protein (APPswe) and mutant presenilin 1 (PS1ΔE9) an increase in the resting Ca2+ concentrations and Ca2+ hyperactivity with abnormal long-projecting intercellular Ca2+ waves were detected in astrocytes surrounding senile plaques. The gene discussed is PSEN1; the disease is Senile plaques.