Another important component of cellular membranes and of lipid rafts, cholesterol, has been recently extensively reviewed in relation to its role in AD (Marzolo and Bu, 2009; Burns and Rebeck, 2010; Mathew et al., 2011) . The picture is by no means a simple one with cholesterol being ascribed both positive and negative roles. Indeed, other diseases are also linked to cholesterol, while it remains unclear which are specifically raft-associated. Such pathologies include Smith-Lemli-Opitz syndrome, Huntington's disease and Niemann-Pick Type C disease (Korade and Kenworthy, 2008) . In terms of normal aging, the data seem to show that the changes in cholesterol are highly dependent on the brain region and cell types used in the studies .