Freeze-fracture studies of reactive myelinated nerve fibres after diffuse axonal injury.
We have studied the axonal and myelin sheath response in diffuse axonal injury after angular acceleration using the freeze-fracture and thin section techniques. It was found that the glial-axonal junction was intact until 1 h after injury. But upon loss of the nodal axolemma specialisations, after 3 to 4 h, the dimeric particles of the glial-axonal junction (GAJ) were lost and, by 6 h, the myelin lamellae became separated from the axonal remnant. There was a correlated loss of glial membrane specialisations of the GAJ during this separation. In the internodal region a suggestion of membrane damage occurred after 20 min but discrete myelin dislocations (particle-free areas) were not found until 1-h survival and were extensive by 6 h. Areas of loosely organised myelin occurred between intact axons at 7-28 days after injury. No evidence for growth cone formation was obtained.
Maxwell
W L
WL
Department of Anatomy, University of Glasgow, Scotland.
Kansagra
A M
AM
Graham
D I
DI
Adams
J H
JH
Gennarelli
T A
TA
D000818:Animals; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D005614:Freeze Fracturing; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000648:ultrastructure*; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D010215:Papio; D013997:Time Factors