Figure 1.

α₂δ-4 and Cachd1 can be expressed on the somato-dendritic and axonal surface. (A) Live cell surface staining of wildtype primary hippocampal neurons overexpressing soluble eGFP together with HA-tagged constructs of α₂δ subunits or Cachd1. (A) The somatic expression pattern of the anti-HA labelling revealed that all α₂δ subunits and Cachd1 can be expressed on the neuronal surface. (B) Anti-HA and synapsin immunofluorescent labelling revealed that all α₂δ subunits and Cachd1 show synaptic and dendritic membrane targeting (white arrowheads). Neurons overexpressing α₂δ-1 displayed a weaker expression pattern on the somatic, dendritic, and axonal surface compared to α₂δ-2, α₂δ-4, and Cachd1. (C) Quantification of the average HA fluorescent intensities illustrated that the surface expression of α₂δ-1 was reduced compared to those of the other subunits. α₂δ-2 expression in soma, dendrites, and axons was higher compared to α₂δ-1, α₂δ-4, and Cachd1. Quantification data are shown as values for individual cells (dots) and means ± SEM. ANOVA with Tukey’s multiple comparison test (C) 16–22 cells per condition from three independent culture preparations. F_{(3, 60)} = 53.6, p < 0.0001. Significances of post hoc test (*** p < 0.001, ** p < 0.01, * p < 0.05) in comparison to α₂δ-1, unless otherwise indicated, are indicated with asterisks. Scale bars, 5 µm.