Figure 3

Alternative cleavage of APP to produce four peptides that mediate synaptic loss, neurite retraction, and ultimately programmed cell death ("the four horsemen"); or three peptides that mediate synaptic maintenance and inhibit programmed cell death ("the wholly trinity").

Among the factors that mediate the decision between these two pathways are included trophic effects such as netrin-1 and anti-trophic effects such as Aβ peptide.