Abstract: Brainstem of rats were stabbed with a needle and pathological changes of neurons and axons in brainstem were observed at different time after injury with Nissl′ s body staining, silver staining and modified trichrome staining. It was found that, by silver staining, the axons showed irregular swelling and disconnection at 1～ 3h, marked swelling of the severe end at 6h, retraction ball at 15h and remarkable retraction ball at 24h. By modified trichrome staining, the space between myelin sheaths and axons was widened at 3～ 6h, and tortuous myelin sheaths adhered incompletely on axons, or even peeled off at 15h to 24h. Perinuclear lysis of Nissl′ s bodies at 24h after injury could be seen by Nissl body staining. The results indicated that, the pathological changes in injured brainstem could be observed with histochemical staining, which might be used for timing brainstem injuries.

Key words: brainstem injury, pathology, histochemistry