Figure 6

Cx32, Cx36, Cx45, and Cx47 are expressed by rare cells and are laminin-responsive. Cx45 (a, arrows) and Cx47 (c, arrows) were expressed in rare populations of cells. Cx45 was detected in Type 2a nestin⁺ cells (b, inset). Cx47 was restricted to RIP⁺ oligodendrocytes (d, inset). Both connexins were downregulated when plated on a laminin substrate (Cx45 e-g, Cx47 h-j). Cx32 (k) and Cx36 (o) protein was not detected in the absence of laminin but was induced following adherence to substrate (Cx32 (l-n) and Cx36 (p-r)). To confirm the lack of Cx32 protein in suspension cultures, western analysis was performed using adult WT brain as a positive control (k, inset). Similarly, western analysis was carried out to confirm Cx36 expression in the + laminin condition and to verify antibody specificity (p, inset). Adult WT and null-mutant (KO) brain served as positive and negative controls. Actin immunoblotting was performed as a loading control. Scale bars, 50 μm, Insets, 25 μm. **p < 0.01 Student's t-test.