Orally available compound prevents deficits in memory caused by the Alzheimer amyloid-beta oligomers.

Matthew Townsend, James P Cleary, Tapan Mehta, Jacki Hofmeister, Sylvain Lesne, Eugene O'Hare, Dominic M Walsh, Dennis J Selkoe

Index: Ann. Neurol. 60(6) , 668-76, (2006)

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Abstract

Despite progress in defining a pathogenic role for amyloid beta protein (Abeta) in Alzheimer's disease, orally bioavailable compounds that prevent its effects on hippocampal synaptic plasticity and cognitive function have not yet emerged. A particularly attractive therapeutic strategy is to selectively neutralize small, soluble Abeta oligomers that have recently been shown to mediate synaptic dysfunction.Using electrophysiological, biochemical, and behavioral assays, we studied how scyllo-inositol (AZD-103; molecular weight, 180) neutralizes the acutely toxic effects of Abeta on synaptic function and memory recall.Scyllo-inositol, but not its stereoisomer, chiro-inositol, dose-dependently rescued long-term potentiation in mouse hippocampus from the inhibitory effects of soluble oligomers of cell-derived human Abeta. Cerebroventricular injection into rats of the soluble Abeta oligomers interfered with learned performance on a complex lever-pressing task, but administration of scyllo-inositol via the drinking water fully prevented oligomer-induced errors.A small, orally available natural product penetrates into the brain in vivo to rescue the memory impairment produced by soluble Abeta oligomers through a mechanism that restores hippocampal synaptic plasticity.