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PROGRESSIVE CENTRALIZATION OF MIDBRAIN HYPERACTIVITYAFTER ACOUSTIC TRAUMA

W. H. A. M. MULDERS* AND D. ROBERTSONPresenter: Danyi LU

Neuroscience 192 (2011) 753–760

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spontaneous firing rates (SFRs)

what's new

• Acoustic trauma Central hyperactivity

• Early stage: continued peripheral afferent input• Later stage: intrinsically generated within the central nervous

system

Abbreviation:spontaneous firing rates -SFRsinferior colliculus -ICcentral nucleus of the inferior colliculus -CNICcompound action potential-CAP

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EXPERIMENTAL PROCEDURES

overall experimental design

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1.animals

2.anesthesia and surgery

3.inferior colliculus recording*

4.cochlear ablation

5.data analysisi

EXPERIMENTAL PROCEDURES

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RESULTS-Cochlear thresholds

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RESULTS-Cochlear thresholds

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RESULTS-Summary of all data

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RESULTS-Hyperactivity in CNIC

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RESULTS-Effects of cochlear ablation on hyperactivity

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RESULTS-Comparison with shorter recovery data

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RESULTS-elevated SFRs in CNIC neurons after acoustic trauma were more commonly observed in CF regions of the CNIC that correlate with the

frequencies in the cochlea

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Discussion-differential effect of cochlearablation at the two stages

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Important consequences for possible mechanisms and treatment of tinnitus

Recent-onset TinnitusLong-standing Tinnitus

Significance