Fig. 5. Effect of cytochalasin B on aggregation and compaction of LNER cells treated or not treated with 4OHT. LNER cells were trypsinized and placed in suspension culture in the presence of 1 µM cytochalasin B, with (+) or without (-) 4OHT, for 24 hours. Cytochalasin B disrupted F-actin as evidenced by phalloidin staining (right panels). In the absence of 4OHT cytochalasin B had a negative impact on LNER aggregation, when compared to cells without either agent. In the presence of 4OHT the negative effect of cytochalasin B on LNER cell aggregation was attenuated. Moreover, the line of phase density (arrows) seen in compacted aggregates of 4OHT-treated LNER cells without cytochalasin B were observed in the smaller aggregates formed by LNER cells treated with both 4OHT and cytochalasin B.