Age-related changes in murine bladder structure and sensory innervation: a multiphoton microscopy quantitative...

Area of Science:

• Urology
• Gerontology
• Microscopy

Background:

• The aging process affects various organs, including the bladder.
• Understanding age-related structural changes in the bladder is crucial for geriatric health.
• Previous studies have not fully quantified these changes in healthy aging bladders.

Purpose of the Study:

• To quantify age-related structural and innervation alterations in healthy mouse bladders.
• To utilize ex vivo two-photon laser scanning microscopy (TPLSM) for detailed bladder wall analysis.
• To compare bladder morphology and nerve density across different age groups.

Main Methods:

• Examination of ex vivo bladders from 25-, 52-, and 85-week-old C57bl/6J mice.
• Morphological analysis and quantification of cell layers and nerves using TPLSM.
• Quantification of nerve morphology (stretched, curled, branched) and collagen-smooth muscle ratio.

Main Results:

• Significant age-related differences in bladder wall architecture and innervation were observed.
• Older mice (85 weeks) exhibited detached urothelial cells and increased connective tissue (collagen-smooth muscle ratio: 1.15 ± 0.29).
• A notable increase in total and curled nerves was found in older mice, suggesting heightened nerve activity.

Conclusions:

• TPLSM is effective for quantifying age-related changes in healthy aging mouse bladders.
• Aging leads to significant structural remodeling and altered innervation in the mouse bladder.
• Increased curled nerves may indicate enhanced neurotransmitter release and potential nerve impairment with age.