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Published on: February 20, 2019
Severe vestibular dysfunction and altered vestibular innervation in mice lacking prosaposin
1Department of Otolaryngology-Head & Neck Surgery, University of California San Francisco, San Francisco, CA 94143-0449, United States. oakil@ohns.ucsf.edu
Neuroscience Research
|February 14, 2012
Summary
Prosaposin is crucial for maintaining balance and hearing. Its absence in mice led to severe vestibular dysfunction and abnormal neuronal growth in the inner ear, highlighting its role in sensory system development.
Area of Science:
- Neuroscience
- Cell Biology
- Genetics
Background:
- Prosaposin (PS) is a precursor to saposins A, B, C, and D, vital for lysosomal hydrolase activity.
- Previous research linked prosaposin to cochlear innervation and hearing maintenance.
Purpose of the Study:
- To investigate prosaposin's role in the vestibular system.
- To determine the effects of prosaposin ablation on balance and vestibular function.
Main Methods:
- Localization studies using RT-PCR, Western blot, and immunofluorescence in normal mice.
- Behavioral testing to assess vestibular function in prosaposin knockout (KO) mice.
- Histological and electron microscopy analysis of vestibular end-organs in KO mice.
- Immunofluorescence staining for neuronal markers (neurofilament 200, synaptophysin).
Main Results:
- Prosaposin is present in vestibular end-organs and Scarpa's ganglion.
- Prosaposin ablation resulted in severe vestibular dysfunction.
- KO mice showed abnormal cellular proliferation, inclusion bodies, and disrupted neuroepithelial structure.
- Evidence of afferent and efferent neuronal overgrowth was observed in KO mice.
Conclusions:
- Prosaposin is essential for normal vestibular system function.
- Prosaposin plays a critical role in the maturation and maintenance of vestibular sensory epithelium and its innervation.
- These findings extend prosaposin's known functions beyond hearing to include balance regulation.
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