Objective: To investigate and analyze the changes of neuronal-apoptosis and the expression of caspase-3 for finding out a new method of injury timing after brain contusion in human.
Methods: The tissue was stained by TUNEL for apoptosis and by immunohistochemistry for caspase-3. Image analysis technique was employed.
Results: The nerve cells stained positive by TUNEL and Caspase-3 immunohistochemistry were distributed in the penumbra and central area. Both these areas were in striking contrast with the distal area or those of control group. The positive staining was more prominente in penumbra area than in central area (P < 0.05). The changes of TUNEL staining and expression of Caspase-3 in penumbra area gradually increased with the survival period after injury; they were parallel to each other. There were linear relationships between the time of injury in 48 hours and the increase in the mean of integral optical density (IOD), the coefficient of correlation (r) being 0.93 and 0.69 for the two staining methods, and two linear regression formulae were induced, respectively.
Conclusion: Observations on the increasing of neuronal apoptosis and Caspase-3 expression in relation with the survival period after injury could be utilized in the timing of brain contusion.