Table 1.

Model Parameters and their Estimated Values

Symbol	Description	Estimated Value	Unit	Reference
S	concentration of Aβ oligomers in soluble form	variable	micromolar	N/A
F	concentration of Aβ oligomers in fiber form	variable	micromolar	N/A
R	mean rate of sAβ secretion by neurons	variable	μM day−1	(50)
a	normalized amplitude of circadian rhythm in sAβ production	25%	N/A	(50,63, 64, 65)
τ	period of circadian rhythm	∼1	day	N/A
M	number density of microglia, Nmgl/Vbrain, assuming that microglia/neuron ratio is unity	∼ 6.7 × 107	mL−1	(66,67)
kp	rate constant of Aβ fiber growth	2.1 × 101	μM−1 day−1	(44)a
kn	rate constant of Aβ fiber nucleation	2.2 × 10−1	μM−1 day−1	(44)a
ds	rate of sAβ clearance by microglia	5.3 × 10−9	day−1 mL	(31,34,35)
es	rate of sAβ efflux through the CSF	1.9	day−1	(29,30)
df	clearance of fAβ by microglia	∼ds/30	day−1 mL	(36)

It is noted that for all the analysis in this work, the parameters are taken from this table unless otherwise specified. N/A, not applicable.

^aEstimation of k_n and k_p has been done using the differential evolution method (see Fig. 1B; (68)).