Facial nerve axotomy in aged and young adult rats: analysis of the glial response.

Abstract

With increasing age, there is a trend towards greater morbidity and injury extent with brain injury. Because several reports have suggested that microglia and astrocytes have an exacerbated response to brain injury in the aged, we set out to explore glial responses to facial nerve axotomy. This model was chosen because the glial responses are well-characterized in young rats and there is no perturbation of the blood-brain barrier (BBB). Immunohistochemistry was performed for glial fibrillary acidic protein (GFAP), leukocyte common antigen, type 3 complement receptor, and major histocompatability complex classes I and II. Quantitative analysis showed that age does not affect the glial response to axotomy in the lesioned facial nucleus; however, an aging-related contralateral effect with enhanced GFAP-labeling was observed. Interestingly, despite a lack of infiltrating neutrophils, a T cell influx was observed in both young and aged rats. Overall, these results suggest that neutrophil extravasion and BBB breakdown are underappreciated with regards to aging and injury exacerbation.

• Authors: Sean D Hurley, Paul D Coleman
• Journal: Neurobiology of aging (Neurobiol Aging) 2003 May-Jun Vol. 24 Issue 3 Pg. 511-8 ISSN: 0197-4580 [Print] United States
• PMID: 12600726 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Glial Fibrillary Acidic Protein

Topics

• Aging (pathology)
• Animals
• Astrocytes (pathology)
• Axotomy (adverse effects)
• Blood-Brain Barrier (physiology)
• Disease Models, Animal
• Facial Nerve (pathology, surgery)
• Facial Nerve Injuries (pathology, physiopathology)
• Glial Fibrillary Acidic Protein (analysis)
• Male
• Microglia (pathology)
• Pons (pathology)
• Rats
• Rats, Inbred F344