Although exogenous nerve growth factor (NGF) demonstrated great potential for post-traumatic stress disorder (PTSD) treatment, its therapeutic effect and underlying cytological mechanism were not fully elucidated so far. We employed a controlled, prospectively designed modified single prolonged stress mice model to investigate the role of exogenous NGF on the modified single prolonged stress induced PTSD-like symptoms and hippocampal cytoarchitecture impairment, as well as the potential neuronal signaling modulation. We discovered that the modified single prolonged stress-exposure induced significant PTSD-like symptoms as well as mildly impaired hippocampal Cornu Ammonis 1 (CA1) subregion cytoarchitecture, but not dentate gyrus neurogenesis, together with a gradual inhibition of TrkA-CREB-ERK signalings in hippocampal CA1 subregion. NGF treatment dose-dependently ameliorated the modified single prolonged stress induced PTSD-like symptoms. NGF increased the cytoplasm/nucleus ratio and improved the neuronal plasticity, mainly via the TrkA-ERK-CREB pathway. Our study offered the translational evidence for the potential application of exogenous NGF for treating or early preventing PTSD after stress exposure.