Collectively, these investigations point to the role of Ach and serotonin in retaining microglia in their anti-inflammatory resting state, backing our results, where AD-like insult, as shown herein, displayed lower hippocampal content of both neurotransmitters along with increased immunoexpression of Iba-1, as well as hippocampal contents of NOS2 and nitrated Aβ, indicating the tilting of microglia toward pro-inflammatory M1 polarization. This evidence concerns the gene NOS2 and Alzheimer disease.