Maturation of spontaneous firing properties after hearing onset in rat auditory nerve fibers: Spontaneous rates, refractoriness, and interfiber correlations

Jingjing Sherry Wu, Eric D. Young, Elisabeth B Glowatzki

Research output: Contribution to journalArticle

Abstract

Auditory nerve fibers (ANFs) exhibit a range of spontaneous firing rates (SRs) that are inversely correlated with threshold for sounds. To probe the underlying mechanisms and time course ofSRdifferentiation during cochlear maturation, loose-patch extracellular recordings weremadefromANFdendrites using acutely excised rat cochlear preparations of different ages after hearing onset. Diversification of SRs occurred mostly between the second and the third postnatal week. Statistical properties of ANF spike trains showed developmental changes that approach adult-like features in older preparations. Comparison with intracellularly recorded EPSCs revealed that most properties of ANF spike trains derive from the characteristics of presynaptic transmitter release. Pharmacological tests and waveform analysis showed that endogenous firing produces some fraction of ANF spikes, accounting for their unusual properties; the endogenous firing diminishes gradually during maturation. Paired recordings showed that ANFs contacting the same inner hair cell could have different SRs, with no correlation in their spike timing.

Original languageEnglish (US)
Pages (from-to)10584-10597
Number of pages14
JournalJournal of Neuroscience
Volume36
Issue number41
DOIs
Publication statusPublished - Oct 12 2016

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Keywords

  • Auditory nerve fiber
  • Development
  • Hair cell
  • Intrinsic firing
  • Refractoriness
  • Spontaneous rate

ASJC Scopus subject areas

  • Neuroscience(all)

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