PRNP and Alzheimer disease: , unlike ICSM18, ICSM41 did notprevent Aβ1–42 protofibrilbinding to PrPC (Fig. 10b,c).Consistent with the differential ability of these two antibodies to preventAβ1–42 binding toPrPC,ICSM18 abrogated the facilitation of LTD by soluble AD brain extract, whereasthe same dose of ICSM41 had no effect (Fig. 9c,d).