Bcl-2 engineered neuroepithelial stem cell transplantation results in increased relaxation of the colonic muscle. (A) Representative recordings showed the responses of the colonic circular muscle to electrical field stimulation (EFS) before and after incubation with 1 μmol/l tetrodotoxin (TTX) in four groups. ↓Marker of EFS (10 Hz) treatment. (B) Quantification of the value R at different frequencies in four groups. *Significantly different from normal, control and Bcl-2 groups. #Significantly different from control group. ##Significantly different from Bcl-2 group with P < 0.05 (n = 8 for each group). NESC, neuroepithelial stem cell.