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In Ovo Electroporation in the Chicken Auditory Brainstem
Published on: June 9, 2017
Morphometric changes in the chick nucleus magnocellularis following acoustic overstimulation
J C Saunders1, H J Adler, Y E Cohen
1Department of Otorhinolaryngology: Head and Neck Surgery, University of Pennsylvania, Philadelphia 19104, USA. saunderj@mail.med.upenn.edu
The Journal of Comparative Neurology
|February 10, 1998
Summary
Intense sound exposure shrinks nucleus magnocellularis (NM) cells in chicks, but cell size recovers within 43 days. NM structure and cell density remained unaffected by noise exposure.
Area of Science:
- Neuroscience
- Auditory Neuroscience
- Cell Biology
Background:
- Intense sound exposure can cause cochlear damage.
- The nucleus magnocellularis (NM) is a key auditory processing center in birds.
- Understanding the effects of acoustic trauma on neural structures is crucial for auditory research.
Purpose of the Study:
- To investigate the impact of intense sound-induced cochlear damage on the nucleus magnocellularis (NM) in neonatal chicks.
- To assess the structural recovery of NM cells following acoustic trauma.
- To correlate structural changes with functional recovery timelines.
Main Methods:
- Neonatal chicks were exposed to intense sound and allowed recovery periods of 0, 15, 27, and 43 days.
- Brainstems were processed, sectioned, and NM cells were measured for cross-sectional area.
- NM cell density was calculated at specific percentile positions.
- Age-matched control groups were used for comparison.
Main Results:
- Immediately after sound exposure, NM cell cross-sectional area was significantly reduced.
- NM cell size largely recovered to near-normal levels by 43 days post-exposure.
- The overall coronal area of the NM and NM cell density were not affected by sound exposure at any recovery interval.
Conclusions:
- NM cell size reduction following acoustic injury is reversible.
- Structural recovery of NM cells occurs despite prior functional restoration.
- Shrinkage may result from reduced cochlear nerve activity due to acoustic trauma.
