Gap junctional communication and connexin expression in cultured olfactoryensheathing cells

The olfactory ensheathing cell (OEC) is a unique glial cell able to support neurite outgrowth in the CNS throughout life. The OEC has been described a s having both Schwann cell-like and astrocyte-like characteristics. The pur pose of this study was to compare gap junctional communication and connexin (Cx) expression in cultured olfactory ensheathing cells with both astrocyt es and Schwann cells to establish which of these two cells types they most closely resemble. We examined the Cx mRNA profile of OECs, astrocytes, and Schwann cells using primers to Cx26, Cx32, Cx37, Cx43, Cx46, and Cx50. All connexins tested except Cx50 were expressed by all three cell types when in itially cultured. However, we observed differences in the levels of express ion of Cx32 and Cx26 between astrocytes, Schwann cells, and OECs that becam e pronounced with time. All three cell types show limited and variable gap junctional communication in culture as assessed by the transfer of microinj ected Lucifer yellow. OECs had limited coupling compared with Schwann cells and astrocytes, although the extent of the dye spread through OECs was mor e comparable to that seen with Schwann cells than astrocytes. Thus, OECs di splay a profile of Cx expression that more closely resembles the Cx express ion of Schwann cells rather than astrocytes. J. Neurosci. Res. 65:520-528, 2001. (C) 2001 Wiley-Liss, Inc.