Of the very few studies investigatingthis, Bie et al73 and Lu et al62 reported increasedhippocampal methyl-CpG-binding protein 2 (MeCP2) levels in rodent models of AD.By using a chromatin immunoprecipitation (ChIP) assay, the teams showedincreased cytosine methylation and binding of MeCP2 at the promoter region ofthe gene encoding neuroligin-1 (Nlgn1) in the hippocampus ofAβ1-40-induced rats73 and APP/PS1mice62 compared to their respective controls. Here, NLGN1 is linked to Alzheimer disease.