Figure 1.

Involvement of multiple pathways in Aβ-induced neurodegeneration. Extracellular Aβ induces increased intraneuronal calcium through several different mechanisms, including those represented in this summary. Calpain activation is linked to both N- and C-terminal tau cleavage and the activation of tau kinases. Caspase-cleaved tau is more likely to become aggregated and highly phosphorylated, all or some of which may result in the induction of neuronal death pathways, including apoptosis-associated caspase activation.