mGlu5 receptors and cellular prion protein mediate amyloid-[beta]-facilitated synaptic long-term depression in vivo

• Published in: Nature communications 2014-03, Vol.5, p.3374
• Main Authors: Hu, Neng-wei, Nicoll, Andrew J, Zhang, Dainan, Mably, Alexandra J, O'malley, Tiernan, Purro, Silvia A, Terry, Cassandra, Collinge, John, Walsh, Dominic M, Rowan, Michael J
• Format: Article
• Language: English
• ISSN: 2041-1723
• DOI: 10.1038/ncomms4374

NMDA-type glutamate receptors (NMDARs) are currently regarded as paramount in the potent and selective disruption of synaptic plasticity by Alzheimer's disease amyloid β-protein (Aβ). Non-NMDAR mechanisms remain relatively unexplored. Here we describe how Aβ facilitates NMDAR-independent long-term depression of synaptic transmission in the hippocampus in vivo. Synthetic Aβ and Aβ in soluble extracts of Alzheimer's disease brain usurp endogenous acetylcholine muscarinic receptor-dependent long-term depression, to enable long-term depression that required metabotropic glutamate-5 receptors (mGlu5Rs). We also find that mGlu5Rs are essential for Aβ-mediated inhibition of NMDAR-dependent long-term potentiation in vivo. Blocking Aβ binding to cellular prion protein with antibodies prevents the facilitation of long-term depression. Our findings uncover an overarching role for Aβ-PrPC -mGlu5R interplay in mediating both LTD facilitation and LTP inhibition, encompassing NMDAR-mediated processes that were previously considered primary.