Age-related changes in the murine larynx: initial validation of a mouse model.
OBJECTIVE
Changes in voice are commonly associated with aging (presbyphonia). Age-related voice change significantly impairs elderly individuals' ability to communicate meaningfully with others and affects their quality of life. With changing age demographics in our society and increasing emphasis on quality of life, treatment of presbylaryngis is becoming more paramount.


METHODS
We used 9 aged and 9 young mice to validate a mouse model for the aging larynx. We stained the larynges with Alcian blue to determine the hyaluronic acid content, trichrome stain to determine the collagen content, and immunohistochemical stain for alpha smooth muscle actin to determine the myofibroblast content. Morphometric measurements were performed for muscle area, muscle thickness, and muscle fiber diameter.


RESULTS
Statistically significant differences in the density measurements of hyaluronic acid and collagen reflected decreased hyaluronic acid and increased collagen content in the aging larynx. We found alpha smooth muscle actin-labeled myofibroblasts only in the aged larynges. No statistically significant differences were found in the morphometric measurements.


CONCLUSIONS
Aged mice may make a practical model for the age-related changes in the vocal folds that can be used further in studies aiming to correct these changes.
Abdelkafy
Wael M
WM
Emory Voice Center, Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia 30308, USA.
Smith
Johnathon Q
JQ
Henriquez
Oswaldo A
OA
Golub
Justin S
JS
Xu
Jianguo
J
Rojas
Mauricio
M
Brigham
Kenneth L
KL
Johns
Michael M
MM
D000199:Actins / Q000032:analysis; D000375:Aging / Q000473:pathology*; D000818:Animals; D003094:Collagen / Q000032:analysis; D004195:Disease Models, Animal; D005240:Feasibility Studies; D006820:Hyaluronic Acid / Q000032:analysis; D007830:Larynx / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D012016:Reference Values; D014827:Vocal Cords / Q000473:pathology; D014833:Voice Quality / Q000502:physiology
D000199:Actins; D006820:Hyaluronic Acid; D003094:Collagen