TY - JOUR
T1 - Facial nerve axotomy in aged and young adult rats
T2 - Analysis of the glial response
AU - Hurley, Sean D.
AU - Coleman, Paul D.
N1 - Funding Information:
The authors wish to thank Kristin B. Brown, for her technical assistance, Tracy Montag, for cresyl violet staining, Dr. Ana Rubio and Dr. Wolfgang J. Streit, for their thoughtful comments on the injury paradigm, Dr. John Olschowka, for use of his image analysis system for this experiment, and Dr. Christopher Cox for his assistance with the statistical analysis. S.D.H. was supported by NIA T32 AG00107. P.D.C. is supported by NIA P30 AG08665, NIA LEAD AG1096, and by the Markey Foundation.
PY - 2003/5
Y1 - 2003/5
N2 - 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.
AB - 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.
KW - Astrocytes
KW - Microglia
KW - T cells
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U2 - 10.1016/S0197-4580(02)00097-0
DO - 10.1016/S0197-4580(02)00097-0
M3 - Article
C2 - 12600726
AN - SCOPUS:0037404612
SN - 0197-4580
VL - 24
SP - 511
EP - 518
JO - Neurobiology of Aging
JF - Neurobiology of Aging
IS - 3
ER -