Synaptic Reorganization in the Adult Rat's Ventral Cochlear Nucleus following Its Total Sensory Deafferentation
2011

Synaptic Changes in the Cochlear Nucleus After Hearing Loss

Sample size: 37 publication Evidence: high

Author Information

Author(s): Hildebrandt Heika, Hoffmann Nadine A., Illing Robert-Benjamin

Primary Institution: Neurobiological Research Laboratory, Department of Otorhinolaryngology, University of Freiburg, Freiburg, Germany

Hypothesis

What is the impact of total sensory deafferentation on synaptic contacts in the cochlear nucleus?

Conclusion

The study found that total sensory deafferentation leads to a significant reduction in synaptic contacts in the cochlear nucleus, but also indicates a potential for synaptic reorganization and new synapse formation.

Supporting Evidence

  • The density of synaptic contact zones was found to be 1.11±0.09×10^9 per mm3 in normal rats.
  • After cochlear ablation, the number of synaptic contact zones decreased by 46% within 7 days.
  • By 10 weeks post-deafferentation, the density of synaptic contact zones nearly recovered to normal levels.

Takeaway

When rats lose their hearing, the connections in their brain that help them hear change a lot, but some new connections can form over time.

Methodology

The study used quantitative electron microscopy to analyze synaptic contact zones in the cochlear nucleus of rats before and after cochlear ablation.

Limitations

The study did not account for potential tissue shrinkage due to histochemical treatment in its density calculations.

Participant Demographics

Adult Wistar rats aged 7 to 20 weeks.

Statistical Information

P-Value

p<0.001

Statistical Significance

p<0.001

Digital Object Identifier (DOI)

10.1371/journal.pone.0023686

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