Fig. 6.

SynCAM1-mediated adhesion in hypothalamic astrocytes is coupled to erbB4 receptor activation. A, SynCAM1-Fc-coated beads adhere less to GFAP-DNerbB4 hypothalamic astrocytes than to WT astrocytes. The number of adherent WT or GFAP-DNerbB4 astrocytes to SynCAM1-Fc was determined 18 h after seeding. *, P < 0.05 vs. adhered WT astrocytes. B, Adhesion of SynCAM1-Fc-coated beads to GFAP-DNerbB4 astrocytes is not different from that of ΔECD-Fc-coated beads. SynCAM1-Fc adhesion is expressed relative to the ΔECD-Fc control group. C and D, Images illustrating the absence of adhesion of both SynCAM1-Fc beads (C) and ΔECD-Fc control beads (D) to GFAP-DNerbB4 astrocytes. In both cases, beads are shown in green, and the astrocytes are identified by phalloidin staining (red). E, SynCAM1-mediated adhesiveness in hypothalamic astrocytes is transiently increased after exposure of the cells to NRGβ1 (3 nm). SynCAM1-Fc-coated beads were presented to WT astrocytes for 10, 20, and 40 min in the presence (black bars) or absence (gray bars) of NRGβ1. At each time point, the data are expressed as a fold change of SynCAM1-Fc-coated beads adhered relative to the nonstimulated control. Numbers in parentheses are number of coverslips per treatment. Vertical lines represent sem. *, P < 0.05 vs. nonstimulated controls. Bars (C and D), 15 μm.