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Ca2+ Channel Expression in the Oligodendrocyte Lineage


H. Kettenmann, as above


The development of oligodendrocytes from their precursor cells through different developmental stages can be studied in vitro. These stages can be distinguished by specific monoclonal antibodies and by a characteristic K+ channel profile. In this study we demonstrate that the occurrence of Ca2+ currents also undergoes marked changes during the development of mouse oligodendrocytes. Immature precursor cells which can develop into astrocytes or oligodendrocytes expressed two different types of voltage-activated Ca2+ channels. The expression of Ca2+ channels in precursor cells was strongly correlated with the expression of Na+ channels. When cells started to express the O1 antigen and were committed to the oligodendrocyte lineage, Ca2+ and Na+ currents could no longer be detected. Large Ca2+ currents were, however, recorded later in the development of the oligodendrocytes, correlated with the expression of the O10 antigen. The Ca2+ channels were classified as high and low voltage-activated Ca2+ channels according to their range of activation, and are further described by their kinetic and pharmacological properties.