Effect of naturally secreted amyloid-beta fibrils and synthetic amylod-beta peptides in an invertebrate memory model

FELD M; GALLI C; PICCINI A; ROMANO A

Pinamar, Buenos Aires

Congreso; XX Reunión Anual de la SAN; 2005

Amyloid ß protein (Aß) fibrillogenesis is considered one of the crucial steps of Alzheimer’s disease pathogenesis. Although several studies have reported data about structure and biological effects of fibrillar synthetic Aß, very little is known about endogenous neuronal amyloid fibrils and their biological effect on memory processes. Recently, it was proposed that memory deficits are caused by different stages of aggregation, particularly by oligomers and by different Ab peptides composition.  Here we evaluated the effect of naturally secreted fibrils and different Ab peptides administration in the context-signal memory of the crab Chasmagnathus. We found a clear amnestic effect at very low doses of naturally secreted Ab fibrils, fibrillated synthetic Ab1-42 and Ab3-42 but, unexpectedly, no amnestic effect of Ab1-40 was observed. Conversely, no amnestic effect was found when administered non-fibrillated oligomerized Ab1-42 peptides. Effect of fibrills on ERK pathway was evaluated as well. Thus, effects on memory were only found in the case of fibrillated peptides administration.