The studies described here were supported in part from a grant from the Veterans Administration by the US National Institutes of Health grants to G.M.P. and by grant from Alzheimer’s Association (IIRG-08-89354) to B.G. The authors thank Dr Ottavio Arancio (Columbia University) for his advice on the reported electrophysiological recording and thank Ms. Amanda Bilski for assisting in preparation of the manuscript.