Relevance of Aβ 1-42 Intrahippocampal Injection as An Animal Model of Inflamed Alzheimer's Disease Brain

Injection of amyloid-beta peptide (Aβ 1-42) into hippocampal and cortical regions of brain may have utility as an animal model of Alzheimer's disease (AD) emphasizing the inflammatory component of disease pathology. This review summarizes recent evidence supporting the relevance of the peptide injection model to describe inflammatory conditions in AD brain. A wide spectrum of responses are considered from effects of Aβ 1-42 on animal behavior and cognitive performance to peptide actions at the cellular and molecular levels. In the latter case a particular focus is placed on inflammatory responses mediated by activated microglia. Specific pharmacological modulations of microglial signaling pathways and factors and how they shape patterns of inflammatory reactivity in peptide-injected brain are included. Overall, the considerations for the validity and limitations of Aβ 1-42 injection as an animal model for AD pathology are also discussed.