[Neurobehavior changes of rats after diffuse axonal injury and the treatment effect with cyclosporin A]

To observe rat's memory and learning behavior after diffuse axonal injury (DAI) and evaluate the treatment efficacy of cyclosporin A (CsA).

Twenty-four SD rats were divided into three groups: non-injured group (n=8), vehicle-treated group (n=8) to whom saline was applied and CsA-treated group (n=8). By analyzing behavior changes of rats in Morris water maze and dark-avoidance test, the CsA treatment efficacy was evaluated.

The Morris water maze was used to observe rats' memory and learning behavior. During a place-training experiment, the latency to find platform in each trial descended remarkably. Vehicle-treated group exhibited acquisition deficits compared with CsA-treatment group. The latency in each trial was longer in vehicle-treated group (F=60.44, P<0.01). With continued training, the rats' performance in CsA-treatment group was better than those in control brain-injured group in crossing platform test (F=-4.00, P<0.01), but no difference with the normal group. In dark-avoidance test, the rats in normal control group had remembered the electricity shock very fast, and seldom entered into dark chamber. The mean latency time was (292.88+/-12.61) seconds. The latency time of rats in CsA-treated group was (224.75+/-55.95) seconds. The latency time of rats in vehicle-treated group was (153.25+/-69.36) seconds. The time of rats in CsA-treated group was shorter than the time of vehicle-treated group animal(F=-71.50, P<0.05).

The rats' memory function is impaired after DAI. The learning acquisition and memory retention impairments are ameliorated after administration of CsA.