Fig. 4

Extracellular Aβ concentrations under normal and pathological conditions. The extracellular Aβ concentration C_ES3 displays oscillatory behaviors depending on the parameters. The basal value of the Aβ generation rate constant (β = β⁽⁰⁾) was used for the normal condition while a high Aβ generation rate β = 100 × β⁽⁰⁾ has been used for the early and late stage AD. For the late stage AD, the specific rate constants of autolysosome formation and intralysosomal hydrolysis have been set equal to r_l3 = 0.1 × r_l3⁽⁰⁾ and r_h3 = 0.1 × r_h3⁽⁰⁾, in addition to the high Aβ generation rate. The results in the second column were obtained under 20-fold increase in the autophagosome formation rate constant (r_g3 = 20 × r_g3⁽⁰⁾), with other parameters remaining unchanged