Insulin also shows neuroprotective effects: intracarotid insulin attenuates phosphorylation of IRß in microvessels in 3xTg-AD mice [251], while intranasal insulin decreases 3-nitrotyrosine levels in the cortex and hippocampus [248], reduces microglial number and CD68 expression in the same model [249]. This evidence concerns the gene INSR and Alzheimer disease.