Fig. 4

The in vitro effect of Schwann cell-secreted Btc on axon elongation. a The amount of Schwann cell-secreted Btc in Schwann cells transfected with siRNA control or siRNA-Btc. The concentration of Btc was summarized from three experiments. Statistical evaluation was performed using t-test. *p-value < 0.05 versus siRNA control. b The schematic diagram of the co-culture of Schwann cells and neurons. c Representative immunofluorescence images and normalized neurite length of neurons co-cultured with transfected with siRNA control or siRNA-Btc. Scale bars represented 50 μm. Neurite length was summarized from three experiments. Statistical evaluation was performed using Mann–Whitney test. *p-value < 0.05 versus neurons co-cultured with Schwann cells transfected with siRNA control