Figure 4 - Distribution of internalized fluo-NT in COS-7 cells transfected with cDNA encoding the high-affinity NT receptor (NT-1). Cells were incubated for 20 min with 20 nM fluo-NT and subjected to a hypertonic acid wash. Internalized ligand forms small, rounded hot spots that pervade the cytoplasm but spare the nucleus (n). Scale bar: 10 Ám.