Figure 6.

Overexpression of α₂δ-1, α₂δ-4, or Cachd1 does not increase clustering of N-type channels. (A) Immunofluorescence analysis of axonal varicosities from wildtype neurons overexpressing eGFP and α₂δ or Cachd1 constructs, labelled against synapsin and Ca_V2.2. Micrographs show immunofluorescent signals of Ca_V2.2 channels at presynaptic boutons, identified by eGFP expression (outlined with a dashed line) and presynaptic synapsin labelling along untransfected dendrites (see also qualitative linescan analysis). Neurons overexpressing α₂δ-1, α₂δ-4, or Cachd1 exhibited Ca_V2.2 levels similar to those of the eGFP control. Quantification of Ca_V2.2 (B) and synapsin 1 (C) shows values for individual cells (dots) and means ± SEM. Cells were obtained from three independent culture preparations. ANOVA with Tukey’s multiple comparison test. (B) 24–39 cells per condition, F_{(3, 110)} = 1.58, p = 0.20. (C) 24–39 cells per condition, F_{(3, 110)} = 0.99, p = 0.40. Scale bar, 1 µm.