Cholesterol homeostasis markers are localized to mouse hippocampal pyramidal and granule layers

Changes in brain cholesterol homeostasis are associated with multiple diseases, such as Alzheimer's and Huntington's; however, controversy persists as to whether adult neurons produce their own cholesterol, or if it is outsourced to astrocytes. To address this issue, we analyzed 25 genes most immediately involved in cholesterol homeostasis from in situ data provided by the Allen Brain Mouse Atlas. We compared the relative mRNA expression in the pyramidal and granule layers, populated with neurons, with the rest of the hippocampus which is populated with neuronal processes and glia. Comparing the expression of the individual genes to markers for neurons and astrocytes, we found that cholesterol homeostasis genes are preferentially targeted to neuronal layers. Therefore, changes in gene expression levels might affect neuronal populations directly.