Expression of neurotrimin in the normal and injured adult human spinal cord

• Published in: Spinal cord Vol. 44; no. 5; pp. 280 - 286
• Main Authors: GRIJALVA, I, LI, X, MARCILLO, A, SALZER, J. L, LEVI, A. D
• Format: Journal Article
• Language: English
• Published: London Nature Publishing 01.05.2006; Nature Publishing Group
• Subjects: Age Factors; Aged; Aged, 80 and over; Biological and medical sciences; Cerebrospinal fluid. Meninges. Spinal cord; Cerebrospinal fluid. Spinal cord. Spinal roots. Spinal nerves; Female; Gene Expression Regulation - physiology; GPI-Linked Proteins; Humans; Immunohistochemistry; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neural Cell Adhesion Molecules - metabolism; Neuroglia - metabolism; Neurology; Neurons - metabolism; Neurosurgery; Postmortem Changes; Spinal Cord - metabolism; Spinal Cord - pathology; Spinal Cord Injuries - metabolism; Spinal Cord Injuries - pathology; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Traumas. Diseases due to physical agents; Human; Spinal cord; Nervous system diseases; human spinal cord; Vertebral canal; Spinal cord trauma; Central nervous system disease; Central nervous system; Cell adhesion molecule; neurotrimin (Ntm); injury; Spinal cord disease
• ISSN: 1362-4393; 1476-5624
• DOI: 10.1038/sj.sc.3101842

Neurotrimin (Ntm) is a member of the family of neural cell adhesion molecules. Its expression pattern suggests that Ntm promotes axonal fasciculation, guides nerve fibers to specific targets and stabilizes synapses as it accumulates coincident with synaptogenesis. Strong labeling of Ntm was observed in motor and sensory areas of the postnatal rat cortex. It is not known whether Ntm is present in adult human spinal cord (SC). In the present study, a monoclonal antibody specific for Ntm (1B1), is applied to the first study of the expression of Ntm in normal and injured adult human SC. (1) To investigate the expression pattern of Ntm in adult normal human SC, and (2) to observe the changes of Ntm expression after SC injury and compare the differences between normal and injured adult human SC. Human SC tissue was obtained from necropsies of patients with (n=5) and without (n=4) SC injury. The 1B1 Ntm monoclonal antibody was used for immunohistochemical staining on paraffin embedded sections with an ABC kit. (1) In total, 12 slides were analyzed for each group from both cervical and thoracic levels. Motor neurons and Clarke's neurons and glial-like cells were mild to moderately positive in all uninjured SC specimens. (2) In injured SC, no staining was observed in the injury epicenter between two and three levels proximally and distally, but was detected five levels away. (3) In patients older than 67 years of age, Ntm-positive inclusions were present in the white matter of the SC with or without injury. (4) Some meningeal cells were strongly Ntm-positive, especially in the uninjured human SC. Ntm is expressed by motor and Clarke's neurons and glial cells in uninjured human SC. The downregulation of Ntm in the injured SC suggests that its expression is regulated by afferent input.