Correlation of Histomorphometric Changes with Diffusion Tensor Imaging for Evaluation of Blast-Induced Auditory Neurodegeneration in Chinchilla
| Autor: | Kathiravan Kaliyappan, Sarah F. Muldoon, Marilena Preda, Vijaya Prakash Krishnan Muthaiah, Johan Nakuci, Ferdinand Schweser |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Cochlear Nucleus
Inferior colliculus Chinchilla H&E stain Auditory cortex Cochlear nucleus Nuclear magnetic resonance Blast Injuries biology.animal Evoked Potentials Auditory Brain Stem otorhinolaryngologic diseases medicine Animals Auditory system Auditory Cortex biology Chemistry Neurodegenerative Diseases Original Articles Inferior Colliculi Disease Models Animal Diffusion Tensor Imaging medicine.anatomical_structure Auditory brainstem response Hearing Loss Noise-Induced nervous system Neurology (clinical) Diffusion MRI |
| Zdroj: | J Neurotrauma |
| ISSN: | 1557-9042 0897-7151 |
| DOI: | 10.1089/neu.2020.7556 |
| Popis: | In the present study, we have evaluated the blast-induced auditory neurodegeneration in chinchilla by correlating the histomorphometric changes with diffusion tensor imaging. The chinchillas were exposed to single unilateral blast-overpressure (BOP) at ∼172dB peak sound pressure level (SPL) and the pathological changes were compared at 1 week and 1 month after BOP. The functional integrity of the auditory system was assessed by auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE). The axonal integrity was assessed using diffusion tensor imaging at regions of interests (ROIs) of the central auditory neuraxis (CAN) including the cochlear nucleus (CN), inferior colliculus (IC), and auditory cortex (AC). Post-BOP, cyto-architecture metrics such as viable cells, degenerating neurons, and apoptotic cells were quantified at the CAN ROIs using light microscopic studies using cresyl fast violet, hematoxylin and eosin, and modified Crossmon's trichrome stains. We observed mean ABR threshold shifts of 30- and 10-dB SPL at 1 week and 1 month after BOP, respectively. A similar pattern was observed in DPAOE amplitudes shift. In the CAN ROIs, diffusion tensor imaging studies showed a decreased axial diffusivity in CN 1 month after BOP and a decreased mean diffusivity and radial diffusivity at 1 week after BOP. However, morphometric measures such as decreased viable cells and increased degenerating neurons and apoptotic cells were observed at CN, IC, and AC. Specifically, increased degenerating neurons and reduced viable cells were high on the ipsilateral side when compared with the contralateral side. These results indicate that a single blast significantly damages structural and functional integrity at all levels of CAN ROIs. |
| Databáze: | OpenAIRE |
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