ApoE 4 and ApoE 3 transgenic mice

Transgenic mice carrying either human ApoE4 or ApoE3 allele were purchased from Taconic Biosciences (Rensselaer, NY). These transgenic lines have been shown to transcribe and express appropriate human ApoE3 and ApoE4 protein in the brain, the liver, and other tissues without contamination of the endogenous mouse ApoE gene. We used 9-month-old homozygous mice (littermates) for our experiments. ApoE3 mice and ApoE4 (10-11 animals/ group) were treated with ketones or control saline by daily subcutaneous injections from 9 months of age (ketones, beta-hydroxybutyrate (BHB): 600 mg/kg/day; acetoacetate (ACA): 600 mg/kg/day; ACA: 150 mg/kg/day). All mice were labeled with serial numbers and were blinded to the person who tested their behavior or Western blot etc. After behavioral tests, animals were euthanized. The brain was processed for further analysis.

All mice were housed in a temperature and humidity-controlled vivarium, kept on a 12-hour dark/light cycle, and had free access to food and water. All experimental procedures were approved by the Institutional Animal Care and Use Committee of the Barrow Neurological Institute and performed according to the Revised Guide for the Care and Use of Laboratory Animals.