Worrying About Alzheimer Disease? Don’t!

In Alzheimer disease (AD), neurons secrete two forms of amyloid-β (Aβ) faster than they can be degraded and cleared. The peptides accumulate into plaques and interfere with synaptic function, setting off a cascade of events that might promote apoptosis. To determine whether stress accelerates this process, investigators created a rat model of AD.

Animals living in groups established social hierarchies and received continuous brain infusions of the two Aβ peptides or an inactive peptide for 2 weeks. To induce social stress, investigators moved some rats daily to new groups for 6 weeks (i.e., 4 rat groups: non-Aβ/no-stress controls, Aβ/no-stress, non-Aβ/stress, and Aβ/stress).

Spatial learning was slower in the two Aβ groups than in the two non…