Oligomeric and fibrillar aggregates were not significantly visible in the brain samples injected with Aβ42 species oxidized by photoactivated Alo. Given that Aβ42 oligomers are reported to be neurotoxic by various pathways (e.g., interacting with cellular membranes and damaging intracellular organelles) and fibrillary amyloid plaques are another pathologic feature upon the progression of AD, these overall results imply that the less toxic, off-pathway assembly of the resultant oxidized Aβ species by Alo with photoactivation takes place in vivo