Figure 4.

Depletion of CNTN from OCM by immunoprecipitation or phospholipase C inhibitors reduces its clustering activity. (a) CNTN immunoprecipitated from OCM using either anti CNTN‐IgG4 or CTRL‐IgG4 as shown by Western blot analysis with identification of CNTN in the precipitate; (b) Clustering activity of these OCMs added at 3 DIV to purified hippocampal neurons measured at 17 DIV, mean ± SEM of three different immunoprecipitated OCMs. Significant decrease of the clustering activity of anti‐CNTN treated OCM compared to both untreated OCM and CTRL treated OCM, *p = 0.02, paired t‐test. (c) OCM obtained from oligodendroglial cell cultures treated with phospholipase C inhibitors (U73122, 5 μM or Edelfosine, 10 μM) have a decrease clustering activity compared with control OCM; mean ± SEM, n = 3 and n = 4 different experiments, respectively; ****p < 0.0001; ***p = 0.0002, Dunn's multiple comparison test. OCM, oligodendrocyte conditioned medium; DIV, days in vitro; CNTN, contactin