Neuronal survival in host brain. (A, B, F) The number of neurons labeled by NeuN in host brain significantly decreases following TBI when compared with sham (P <0.05). (B, C, D, E, F) However, separate or combined transplantation of NSCs and OECs increases neuronal number (P <0.05 versus TBI). (C, D, E, F) Furthermore, co-grafting group resulted in the highest number of surviving neurons; higher than the NSC only group or the OEC only group (P <0.05). Scale bars = 100 μm, shown in (A). *Statistical significance of P <0.05. NSC, neural stem cell; OEC, olfactory en sheathing cell; TBI, traumatic brain injury.