Versican Plays An Important Role In Neural Development And Damage Repair In The Cochlea

Meredith Hammer

School Name

South Carolina Governor's School for Science and Mathematics

Grade Level

12th Grade

Presentation Topic

Physiology and Health

Presentation Type

Mentored

Mentor

Mentor: Hainan Lang, Department of Pathology and Laboratory Medicine, Medical University of South Carolina

Abstract

The efficiency of signal transduction in the auditory pathway is vital to hearing function. Hearing loss can be caused by degeneration of neurons as a result of aging, noise damage, decrease in myelination or autoimmune response. Versican, a chondroitin-sulfate proteoglycan of the extracellular matrix, has proven to influence ECM organization in the central nervous system, and has appeared in the cochlea after damage and during postnatal development. V0/V2 Versican knockout (KO) mice were compared with wild type (WT) mice to determine differences in morphology and hearing function. Morphological changes within the Versican KO mice were seen with transmission electron microscopy. The recovery of hearing function after damage was compared between Versican KO and WT mice over 30 days using ABR (Auditory Brainstem Response) testing. Versican KO mice exhibited irregularity of myelin on neuron cell bodies, nodes of Ranvier and axons, as well as axonal changes at the nodes and within the axon. The WT mice exhibited recovery of original pre-damage hearing thresholds while KO mice showed a lack of recovery. These morphological changes in the Versican KO mice can be correlated with the differences in recovery between the two mice. These results suggest that Versican is important in maintaining structural integrity of the auditory nerve neurons, affecting the axon and proper myelination, and is important in damage repair. These results also suggest that the extracellular matrix could influence proper damage recovery or affect other factors like myelination and axonal structure.

Start Date

4-11-2015 11:00 AM

End Date

4-11-2015 11:15 AM

COinS
 
Apr 11th, 11:00 AM Apr 11th, 11:15 AM

Versican Plays An Important Role In Neural Development And Damage Repair In The Cochlea

The efficiency of signal transduction in the auditory pathway is vital to hearing function. Hearing loss can be caused by degeneration of neurons as a result of aging, noise damage, decrease in myelination or autoimmune response. Versican, a chondroitin-sulfate proteoglycan of the extracellular matrix, has proven to influence ECM organization in the central nervous system, and has appeared in the cochlea after damage and during postnatal development. V0/V2 Versican knockout (KO) mice were compared with wild type (WT) mice to determine differences in morphology and hearing function. Morphological changes within the Versican KO mice were seen with transmission electron microscopy. The recovery of hearing function after damage was compared between Versican KO and WT mice over 30 days using ABR (Auditory Brainstem Response) testing. Versican KO mice exhibited irregularity of myelin on neuron cell bodies, nodes of Ranvier and axons, as well as axonal changes at the nodes and within the axon. The WT mice exhibited recovery of original pre-damage hearing thresholds while KO mice showed a lack of recovery. These morphological changes in the Versican KO mice can be correlated with the differences in recovery between the two mice. These results suggest that Versican is important in maintaining structural integrity of the auditory nerve neurons, affecting the axon and proper myelination, and is important in damage repair. These results also suggest that the extracellular matrix could influence proper damage recovery or affect other factors like myelination and axonal structure.