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Papers by Ye-Hyun Kim

Journal of the Association for Research in Otolaryngology

Cross-modal plasticity occurs when the function of remaining senses is enhanced following depriva... more Cross-modal plasticity occurs when the function of remaining senses is enhanced following deprivation or loss of a sensory modality. Auditory neural responses are enhanced in the auditory cortex, including increased sensitivity and frequency selectivity, following short-term visual deprivation in adult mice (Petrus et al. Neuron 81:664–673, 2014). Whether or not these visual deprivation–induced neural changes translate into improved auditory perception and performance remains unclear. As an initial investigation of the effects of adult visual deprivation on auditory behaviors, CBA/CaJ mice underwent binocular enucleation at 3–4 weeks old and were tested on a battery of learned behavioral tasks, acoustic startle response (ASR), and prepulse inhibition (PPI) tests beginning at least 2 weeks after the enucleation procedure. Auditory brain stem responses (ABRs) were also measured to screen for potential effects of visual deprivation on non-behavioral hearing function. Control and enucleated mice showed similar tone detection sensitivity and frequency discrimination in a conditioned lick suppression test. Both groups showed normal reactivity to sound as measured by ASR in a quiet background. However, when startle-eliciting stimuli were presented in noise, enucleated mice showed decreased ASR amplitude relative to controls. Control and enucleated mice displayed no significant differences in ASR habituation, PPI tests, or ABR thresholds, or wave morphology. Our findings suggest that while adult-onset visual deprivation induces cross-modal plasticity at the synaptic and circuit levels, it does not substantially influence simple auditory behavioral performance.

eLife, 2013

Information flow through neural circuits is determined by the nature of the synapses linking the ... more Information flow through neural circuits is determined by the nature of the synapses linking the subtypes of neurons. How neurons acquire features distinct to each synapse remains unknown. We show that the transcription factor Mafb drives the formation of auditory ribbon synapses, which are specialized for rapid transmission from hair cells to spiral ganglion neurons (SGNs). Mafb acts in SGNs to drive differentiation of the large postsynaptic density (PSD) characteristic of the ribbon synapse. In Mafb mutant mice, SGNs fail to develop normal PSDs, leading to reduced synapse number and impaired auditory responses. Conversely, increased Mafb accelerates synaptogenesis. Moreover, Mafb is responsible for executing one branch of the SGN differentiation program orchestrated by the Gata3 transcriptional network. Remarkably, restoration of Mafb rescues the synapse defect in Gata3 mutants. Hence, Mafb is a powerful regulator of cell-type specific features of auditory synaptogenesis that offe...

A Gata3–Mafb transcriptional network directs post-synaptic differentiation in synapses specialize... more A Gata3–Mafb transcriptional network directs post-synaptic differentiation in synapses specialized for hearing (Article begins on next page) The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters.

The Journal of the Acoustical Society of America

Learning and Motivation, 2009

The Journal of General Physiology, 2013

The hyperpolarization-activated current, Ih, is carried by members of theHcnchannel family and co... more The hyperpolarization-activated current, Ih, is carried by members of theHcnchannel family and contributes to resting potential and firing properties in excitable cells of various systems, including the auditory system. Ihhas been identified in spiral ganglion neurons (SGNs); however, its molecular correlates and their functional contributions have not been well characterized. To investigate the molecular composition of the channels that carry Ihin SGNs, we examinedHcnmRNA harvested from spiral ganglia of neonatal and adult mice using quantitative RT-PCR. The data indicate expression ofHcn1,Hcn2, andHcn4subunits in SGNs, withHcn1being the most highly expressed at both stages. To investigate the functional contributions of HCN subunits, we used the whole-cell, tight-seal technique to record from wild-type SGNs and those deficient inHcn1,Hcn2, or both. We found that HCN1 is the most prominent subunit contributing to Ihin SGNs. Deletion ofHcn1resulted in reduced conductance (Gh), slowe...