Immunohistochemical localization of the σ 1-receptor in oligodendrocytes in the rat central nervous system

By using a new polyclonal antibody raised against a 21-amino acid peptide sequence corresponding to the fragment 138–157 of the cloned rat σ 1-receptor, we demonstrated by immunoperoxidase and double immunofluorescence techniques, that rat oligodendrocytes express the σ 1-receptor. Experiments in vivo and in vitro showed that σ 1-receptor colocalized with specific markers of progenitor (A2B5) and mature oligodendrocytes (GalC, RIP). These results suggest that σ 1-receptor in oligodendrocytes might be involved in myelination by direct implication in cholesterol biosynthesis or by interaction with endogenous ligands such as neurosteroids.