N-terminally truncated Aβ in pyramidal neurons in frontal cortex in confocal microscopy and semi-quantification of N-truncated Aβ, HNE and MDA in neurons and in neuropil. (a) Large pyramidal neurons in frontal cortex in layers 3 and 5 in a 10-year-old individual with dup(15)/autism contain granules immunoreactive with mAb 4G8, but not with 6E10, consistent with N-terminally truncated Aβ. Between 20% and 40% of intracellular granular Aβ in this brain are co-localized with autofluorescent granules of lipofuscin. Bars 10 μm. (b) Intensities of the Aβ, MDA and HNE immunoreactivities in individual neurons in the frontal cortex for all brains listed in Table
1 are significantly larger in the dup(15)/autism cases and in the idiopathic autism than in controls. The bars show average + SD. Statistical significance: * p < 0.05, *** p < 0.001.