Immunohistochemical localization of the sigma1-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 sigma(1)-receptor, we demonstrated by immunoperoxidase and double immunofluorescence techniques, that rat oligodendrocytes express the sigma(1)-receptor. Experiments in vivo and in vitro showed that sigma(1)-receptor colocalized with specific markers of progenitor (A2B5) and mature oligodendrocytes (GalC, RIP). These results suggest that sigma(1)-receptor in oligodendrocytes might be involved in myelination by direct implication in cholesterol biosynthesis or by interaction with endogenous ligands such as neurosteroids.