The prion protein as a receptor for amyloid-beta.

Increased levels of brain amyloid-beta, a secreted peptide cleavage product of amyloid precursor protein (APP), is believed to be critical in the aetiology of Alzheimer's disease. Increased amyloid-beta can cause synaptic depression, reduce the number of spine protrusions (that is, sites of synaptic contacts) and block long-term synaptic potentiation (LTP), a form of synaptic plasticity; however, the receptor through which amyloid-beta produces these synaptic perturbations has remained elusive. Laurén et al. suggested that binding between oligomeric amyloid-beta (a form of amyloid-beta thought to be most active) and the cellular prion protein (PrP(C)) is necessary for synaptic perturbations. Here we show that PrP(C) is not required for amyloid-beta-induced synaptic depression, reduction in spine density, or blockade of LTP; our results indicate that amyloid-beta-mediated synaptic defects do not require PrP(c).