Figure 3 - Distribution of fluo-NT-labeled NT-2 receptors on the surface of an astrocyte in culture following 60-min incubation at 37oC with 20 nM fluo-NT. In these cells, which express but do not internalize NT-2 receptors, surface-bound molecules form numerous polymorphic clusters. This labeling is entirely suppressed by a hypertonic acid wash. Scale bar: 20 Ám.