Alzheimer's disease A4 peptide oligomer (A-beta oligomer, A-beta derived diffusable ligand, ADDL)

^[1]^[2]^[3]^[4]^[5]

Function

may bind to PSD-95 at post-synaptic density
binding results in ectopic activation of Arc
phosphatidylinositol may facilite A-beta oligomer formation^[4]
prion protein PrPc (CD230) may be receptor for A4 oligomers; PrPc may bind & internalize A4 oligomers^[5]

oligomers of A4 amyloid peptide, forming reversibly as intermediate(s) to amyloid plaques in Alzheimer's disease.
allegedly the neurotoxic form(s) of A4 amyloid peptide in CSF
A-beta oligomers disrupt cognitive function^[3], specifically A-beta*56

↑ Gilbert BJ. The role of amyloid beta in the pathogenesis of Alzheimer's disease. J Clin Pathol. 2013 May;66(5):362-6 PMID: https://www.ncbi.nlm.nih.gov/pubmed/23526599
↑ Lacor PN, Buniel MC, Chang L, Fernandez SJ, Gong Y, Viola KL, Lambert MP, Velasco PT, Bigio EH, Finch CE, Krafft GA, Klein WL. Synaptic targeting by Alzheimer's-related amyloid beta oligomers. J Neurosci. 2004 Nov 10;24(45):10191-200. PMID: https://www.ncbi.nlm.nih.gov/pubmed/15537891
↑ ^3.0 ^3.1 Cleary JP, Walsh DM, Hofmeister JJ, Shankar GM, Kuskowski MA, Selkoe DJ, Ashe KH. Natural oligomers of the amyloid-beta protein specifically disrupt cognitive function. Nat Neurosci. 2005 Jan;8(1):79-84. Epub 2004 Dec 19. PMID: https://www.ncbi.nlm.nih.gov/pubmed/15608634
↑ ^4.0 ^4.1 McLaurin J, Kierstead ME, Brown ME, Hawkes CA, Lambermon MH, Phinney AL, Darabie AA, Cousins JE, French JE, Lan MF, Chen F, Wong SS, Mount HT, Fraser PE, Westaway D, George-Hyslop PS. Cyclohexanehexol inhibitors of Abeta aggregation prevent and reverse Alzheimer phenotype in a mouse model. Nat Med. 2006 Jul;12(7):801-8. Epub 2006 Jun 11. PMID: https://www.ncbi.nlm.nih.gov/pubmed/16767098
↑ ^5.0 ^5.1 Lauren J et al. Cellular prion protein mediates impairment of synaptic plasticity by amyloid-oligomers. Nature 2009 Feb 26; 457:1128 PMID: https://www.ncbi.nlm.nih.gov/pubmed/19242475
Cisse M and Mucke L. Alzheimer's disease: A prion protein connection. Nature 2009 Feb 26; 457:1090. PMID: https://www.ncbi.nlm.nih.gov/pubmed/19242462