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Morphological observation of rat brain diffuse axonal injury caused by lateral head rotation using NF68 immunohistochemistry

2001; Elsevier BV; Linguagem: Inglês

1008-1275

YI Shengyu,

Cerebrospinal fluid and hydrocephalus

Objective To explore the morphological changes of rat brain diffuse axonal injury (DAI) caused by lateral head rotation. Methods Twelve rats were equally divided into groups of 30 min, 2 h, 24 h post injury and a control group. The rat brain DAI model was produced by lateral head rotation. The brain sagittal sections were processed by using the mouse serum against NF68, a subunit of neurofilament (NF) protein, and immunohistochemical ABC method and DAB+H 2O 2 developing technique. The part of medulla oblongata was cut and embedded between thin slides. Through light microscopical localization, the positive area was selected and cut into supra thin sections,then observed under electron microscope. Results At 30 min after injury, the axons in the medulla oblongata were crooked and swollen under light microscope; and the myelin sheath became slightly separated and the NFs in axoplasma were abnormal in structure under electron microscope. The damage of axons turned to be severer 2 24 h post injury. Apparent axonal swelling, disconnection and formation of axonal retraction balls were seen under light microscope. And separation of myelin sheaths, local disconnection, vacuolization and peripheral accumulation of mitochondria, and partial dissolution of axoplasma were obviously observed under electron microscope. Compared with the control rats, the axoplasma NF68 staining was strengthened after injury; as the axonal structure changed, the NF68 positive axons increased gradually in staining strength and in number. Conclusions The imunnoactivity of NF68 subunits in rat brain neuroaxonal NF proteins is enhanced greatly after lateral head rotation. It leads to a disorder structure of NFs, which finally results in axonal swelling and disconnection and formation of axonal retraction balls.