Functional magnetic resonance imaging of enhanced central auditory gain and electrophysiological correlates in a behavioral model of hyperacusis

Eddie Wong, Kelly Radziwon, Guang Di Chen, Xiaopeng Liu, Francis AM Manno, Sinai HC Manno, Benjamin Auerbach, Ed X. Wu, Richard Salvi, Condon Lau

Research output: Contribution to journalArticlepeer-review

Abstract

Hyperacusis is a debilitating hearing condition in which normal everyday sounds are perceived as exceedingly loud, annoying, aversive or even painful. The prevalence of hyperacusis approaches 10%, making it an important, but understudied medical condition. To noninvasively identify the neural correlates of hyperacusis in an animal model, we used sound-evoked functional magnetic resonance imaging (fMRI) to locate regions of abnormal activity in the central nervous system of rats with behavioral evidence of hyperacusis induced with an ototoxic drug (sodium salicylate, 250 mg/kg, i.p.). Reaction time-intensity measures of loudness-growth revealed behavioral evidence of salicylate-induced hyperacusis at high intensities. fMRI revealed significantly enhanced sound-evoked responses in the auditory cortex (AC) to 80 dB SPL tone bursts presented at 8 and 16 kHz. Sound-evoked responses in the inferior colliculus (IC) were also enhanced, but to a lesser extent. To confirm the main results, electrophysiological recordings of spike discharges from multi-unit clusters were obtained from the central auditory pathway. Salicylate significantly enhanced tone-evoked spike-discharges from multi-unit clusters in the AC from 4 to 30 kHz at intensities ≥60 dB SPL; less enhancement occurred in the medial geniculate body (MGB), and even less in the IC. Our results demonstrate for the first time that non-invasive sound-evoked fMRI can be used to identify regions of neural hyperactivity throughout the brain in an animal model of hyperacusis.

Original languageEnglish (US)
Article number107908
JournalHearing Research
Volume389
DOIs
StatePublished - Apr 2020
Externally publishedYes

Keywords

  • Central auditory gain
  • fMRI
  • Functional magnetic resonance imaging
  • Hyperacusis
  • Rat

ASJC Scopus subject areas

  • Sensory Systems

Fingerprint Dive into the research topics of 'Functional magnetic resonance imaging of enhanced central auditory gain and electrophysiological correlates in a behavioral model of hyperacusis'. Together they form a unique fingerprint.

Cite this