OBJECTIVETo establish a simple, reproducible, and practical mechanical injury model of hippocampal neurons of Sprague-Dawley rats in vitro.

METHODSHippocampal neurons isolated from 1-2-day old rats were cultured in vitro. Mild, moderate and severe mechanical injuries were delivered to the neurons by syringe needle tearing, respectively. The control neurons were treated identically with the exception of trauma. Cell damage was assessed by measuring the Propidium Iodide (PI) uptaking at different time points (0.5, 1, 6, 12 and 24 hours) after injury. The concentration of neuron specific enolase was also measured at some time points.

RESULTSPathological examination showed that degeneration, degradation and necrosis occurred in the injured cultured neurons. Compared with the control group, the ratio of PI-positive cells in the injured groups increased significantly after 30 minutes of injury (P<0.05). More severe the damage was, more PI-positive neurons were detected. Compared with the control group, the concentration of neuron specific enolase in the injured culture increased significantly after 1 hour of injury (P<0.05).

CONCLUSIONSThe established model of hippocampal neuron injury in vitro can be repeated easily and can simulate the damage mechanism of traumatic brain injury, which can be used in the future research of traumatic brain injury.