Recently, a 56-kDa oligomeric Aβ species identified in Tg2576 mice81 has been proposed as a candidate for the toxic effect. Levels of this species, which has been termed Aβ*56, correlate strongly with the degree of memory impairment in Tg2576 mice, and when injected into rats, Aβ*56 disrupts cognitive functioning.81 Studies in 3xTg-AD suggest that levels of Aβ*56 may correlate with pathology and behavioral changes in this line as well.82
