ObjectiveTo explore the influence of embryonic neural stem cell (ENSC) transplantation on learning and memory dysfunction after traumatic brain injury in rats. MethodsA total of 80 adult male SD rats were randomly divided into control group, traumatic brain injury (TBI) group, traumatic brain injury and neural stem cell transplantation (TBI＋NSC) group, traumatic brain injury and PBS transplantation (TBI＋PBS)group. Immunohistochemistry was used to detect the distribution and migration of BrdU＋ and the changes of nerve growth factor (NGF) and brain derived neurophic factor (BDNF) expression in the hippocampus following traumatic brain injury. The spatial cognitive functions of animals were examined by Morris water maze. ResultsENSCs marked with BrdU were found in the hippocampus at 7, 14, 21, and 28 d after transplantation. Increased expression of NGF and BDNF proteins was found around the hippocampus in the TBI＋NSC group, with the IOD values at day 7 being 0.495 4±0.013 4 for NGF and 0.474 5±0.042 5 for BDNF, and the values at day 14 being 0.576 7±0.021 1 for NGF and 0.556 3±0.032 1 for BDNF, which were significantly higher than those in other groups (P<0.05). The escape latency of TBI＋NSC group was significantly decreased compared with TBI and TBI＋PBS groups(P<0.05). ConclusionNeurophic factors are changed in the hippocampus following transplantation of ENSCs, which is of great importance for the recovery of cognitive dysfunction following traumatic brain injury.