Editorial Volume 15, Issue 2 pp 295—297

Figure 1. The segmentally trisomic Ts65Dn mouse carries the majority of triplicated genes seen in human Down syndrome (DS) within the DS critical region (DSCR). As a result of triplication of the amyloid precursor protein within the DSCR, soluble amyloid β (Aβ) increases in the Ts65Dn mouse brain as a function of age, appearing first in the frontal cortex (FC) and hippocampus (Hp). How the time-dependent regional changes in soluble Aβ relate to the documented atrophy of basal forebrain cholinergic circuitry at 6 months is yet to be determined but may relate to endosomal alterations and/or deficient nerve growth factor (NGF) transport in these vulnerable cells. Abbreviations: MS: medial septum; CB: cerebellum; VDB: ventral diagonal band; NBM: nucleus basalis of meynert; SI: substantia innominata.