Research Overview

We have an active research group focused on the function and dysfunction of the inner ear.  Our goal is to understand how stimuli from the external world, such as sound, gravity and head movements are converted into electrical signals, how the information is encoded and how it is transmitted to the brain. Furthermore, we want to understand why genetic mutations cause hearing and balance dysfunction.  We plan to use this information to design novel therapeutic innervations for deafness and balance disorders.

Sensory transduction in the ear beings with deflection of mechanosensitive organelles that project from the apical surface of inner ear hair cells.  The exquisite sensitivity of the auditory system can initiate signals that encode the faint pizzicato of a classical violin.  Remarkably, auditory hair cells can also detect stimuli with amplitudes over a million times greater, and thus can signal the booming cannons of Tchaikovsky's 1812 Overture as well. This extraordinary dynamic range is the result of a sensory transduction process that utilizes several feedback mechanisms to precisely reposition and tune the mechanosensitive apparatus within the optimal range allowing detection of auditory stimuli that span the breadth of amplitudes and frequencies humans encounter daily.

Ongoing projects in the lab include the study of:

  • Mechanotransduction and adaptation in sensory hair cells
  • Firing properties of afferent neurons that relay information to the brain
  • Development of inner ear function
  • Novel gene therapy strategies to treat inner ear dysfunction

Research Background

Jeffrey Holt received a PhD from the University of Rochester in 1995.  He completed a postdoctoral fellowship with the Howard Hughes Medical Institute at Harvard Medical School in the laboratory of David Corey.  In 2001 Dr. Holt accepted a faculty position in the Department of Neuroscience at the University of Virginia.  In 2011 he returned to Harvard to join the Department of Otolaryngology, the F.M. Kirby Neurobiology Center and the Neurobiology Program at Boston Children’s Hospital. Dr. Holt was promoted to Professor of Otolaryngology at Harvard Medical School in 2016.

Selected Publications

  1. Gao X, Tao Y, Lamas V, Huang M, Yeh WH, Pan B, Hu YJ, Hu JH, Thompson DB, Shu Y, Li Y, Wang H, Yang S, Xu Q, Polley DB, Liberman MC, Kong WJ, Holt JR, Chen ZY, Liu DR. Treatment of autosomal dominant hearing loss by in vivo delivery of genome editing agents. Nature. 2018
  2. Koehler KR, Nie J, Longworth-Mills E, Liu XP, Lee J, Holt JR, Hashino E. Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells. Nat Biotechnol. 2017 Jun; 35(6):583-589.
  3. Pan B, Askew C, Galvin A, Heman-Ackah S, Asai Y, Indzhykulian AA, Jodelka FM, Hastings ML, Lentz JJ, Vandenberghe LH, Holt JR, Géléoc GS. Gene therapy restores auditory and vestibular function in a mouse model of Usher syndrome type 1c. Nat Biotechnol. 2017 Mar; 35(3):264-272.
  4. Corey DP, Holt JR. Are TMCs the Mechanotransduction Channels of Vertebrate Hair Cells? J Neurosci. 2016 Oct 26; 36(43):10921-10926.
  5. Liu XP, Koehler KR, Mikosz AM, Hashino E, Holt JR. Functional development of mechanosensitive hair cells in stem cell-derived organoids parallels native vestibular hair cells. Nature Com.. 7:11508, 2016
  6. Akyuz N, Holt JR. Plug-N-Play: Mechanotransduction Goes Modular. Neuron. 89(6):1128-30, 2016.
  7. Askew C, Rochat C, Pan B, Asai Y, Ahmed H, Child E, Schneider BL, Aebischer P, Holt JR. Tmc gene therapy restores auditory function in deaf mice. Science Translational Medicine. 7(295):295ra108, 2015.
  8. Géléoc GS, Holt JR. Sound strategies for hearing restoration. Science. 344(6184):1241062. 2014
  9. Pan B, Géléoc GS, Asai Y, Horwitz GC, Kurima K, Ishikawa K, Kawashima Y, Griffith AJ, Holt JR. TMC1 and TMC2 are components of the mechanotransduction channel in hair cells of the mammalian inner ear. Neuron. 79(3):504-15, 2013.
  10. Kawashima Y, Géléoc GS, Kurima K, Labay V, Lelli A, Asai Y, Makishima T, Wu DK, Della Santina CC, Holt JR, Griffith AJ. Mechanotransduction in mouse inner ear hair cells requires transmembrane channel-like genes. J Clinical Investigation. 121(12):4796-809, 2011.

Media

Researcher Profile

Meet Jeffrey Holt, PhD

Publications

  1. Complexes of vertebrate TMC1/2 and CIB2/3 proteins form hair-cell mechanotransduction cation channels. Elife. 2025 Jan 08; 12. View Abstract
  2. Complexes of vertebrate TMC1/2 and CIB2/3 proteins form hair-cell mechanotransduction cation channels. bioRxiv. 2024 Jul 05. View Abstract
  3. Sensory transduction in auditory hair cells-PIEZOs can't touch this. J Gen Physiol. 2024 Jun 03; 156(6). View Abstract
  4. TMC function, dysfunction, and restoration in mouse vestibular organs. Front Neurol. 2024; 15:1356614. View Abstract
  5. TMEM63 proteins function as monomeric high-threshold mechanosensitive ion channels. Neuron. 2023 10 18; 111(20):3195-3210.e7. View Abstract
  6. Response to Letter to the Editor Regarding "Hearing Preservation and Spatial Hearing Outcomes after Cochlear Implantation in Children with TMPRSS3 Mutations". Otol Neurotol. 2023 Aug 01; 44(7):746. View Abstract
  7. Delivery of gene therapy through a cerebrospinal fluid conduit to rescue hearing in adult mice. Sci Transl Med. 2023 06 28; 15(702):eabq3916. View Abstract
  8. Genotype-Phenotype Correlations in TMPRSS3 (DFNB10/DFNB8) with Emphasis on Natural History. Audiol Neurootol. 2023; 28(6):407-419. View Abstract
  9. Molecular earplugs to protect the inner ear. Mol Ther Methods Clin Dev. 2023 Jun 08; 29:284-285. View Abstract
  10. Hearing Preservation and Spatial Hearing Outcomes After Cochlear Implantation in Children With TMPRSS3 Mutations. Otol Neurotol. 2023 01 01; 44(1):21-25. View Abstract
  11. Optimized AAV Vectors for TMC1 Gene Therapy in a Humanized Mouse Model of DFNB7/11. Biomolecules. 2022 06 29; 12(7). View Abstract
  12. Efficient Viral Transduction in Fetal and Adult Human Inner Ear Explants with AAV9-PHP.B Vectors. Biomolecules. 2022 06 10; 12(6). View Abstract
  13. pH regulates potassium conductance and drives a constitutive proton current in human TMEM175. Sci Adv. 2022 Mar 25; 8(12):eabm1568. View Abstract
  14. Dual-vector gene therapy restores cochlear amplification and auditory sensitivity in a mouse model of DFNB16 hearing loss. Sci Adv. 2021 Dec 17; 7(51):eabi7629. View Abstract
  15. Sensory transduction is required for normal development and maturation of cochlear inner hair cell synapses. Elife. 2021 11 04; 10. View Abstract
  16. Putting the Pieces Together: the Hair Cell Transduction Complex. J Assoc Res Otolaryngol. 2021 12; 22(6):601-608. View Abstract
  17. Neonatal AAV gene therapy rescues hearing in a mouse model of SYNE4 deafness. EMBO Mol Med. 2021 02 05; 13(2):e13259. View Abstract
  18. The Mechanosensory Transduction Machinery in Inner Ear Hair Cells. Annu Rev Biophys. 2021 05 06; 50:31-51. View Abstract
  19. Single and Dual Vector Gene Therapy with AAV9-PHP.B Rescues Hearing in Tmc1 Mutant Mice. Mol Ther. 2021 03 03; 29(3):973-988. View Abstract
  20. Introduction to the Hearing Research special issue on inner ear gene therapy. Hear Res. 2020 09 01; 394:108010. View Abstract
  21. In vivo base editing restores sensory transduction and transiently improves auditory function in a mouse model of recessive deafness. Sci Transl Med. 2020 06 03; 12(546). View Abstract
  22. Efficient viral transduction in mouse inner ear hair cells with utricle injection and AAV9-PHP.B. Hear Res. 2020 09 01; 394:107882. View Abstract
  23. Function and Dysfunction of TMC Channels in Inner Ear Hair Cells. Cold Spring Harb Perspect Med. 2019 10 01; 9(10). View Abstract
  24. Increasing the expression level of ChR2 enhances the optogenetic excitability of cochlear neurons. J Neurophysiol. 2019 11 01; 122(5):1962-1974. View Abstract
  25. Publisher Correction: Continuous evolution of base editors with expanded target compatibility and improved activity. Nat Biotechnol. 2019 09; 37(9):1091. View Abstract
  26. Continuous evolution of base editors with expanded target compatibility and improved activity. Nat Biotechnol. 2019 09; 37(9):1070-1079. View Abstract
  27. Allele-specific gene editing prevents deafness in a model of dominant progressive hearing loss. Nat Med. 2019 07; 25(7):1123-1130. View Abstract
  28. Publisher Correction: Improved TMC1 gene therapy restores hearing and balance in mice with genetic inner ear disorders. Nat Commun. 2019 02 08; 10(1):734. View Abstract
  29. Improved TMC1 gene therapy restores hearing and balance in mice with genetic inner ear disorders. Nat Commun. 2019 01 22; 10(1):236. View Abstract
  30. Split otoferlins reunited. EMBO Mol Med. 2019 01; 11(1). View Abstract
  31. TMC1 Forms the Pore of Mechanosensory Transduction Channels in Vertebrate Inner Ear Hair Cells. Neuron. 2018 08 22; 99(4):736-753.e6. View Abstract
  32. Tmc2 expression partially restores auditory function in a mouse model of DFNB7/B11 deafness caused by loss of Tmc1 function. Sci Rep. 2018 08 14; 8(1):12125. View Abstract
  33. Transgenic Tmc2 expression preserves inner ear hair cells and vestibular function in mice lacking Tmc1. Sci Rep. 2018 08 14; 8(1):12124. View Abstract
  34. Regenerating hair cells in vestibular sensory epithelia from humans. Elife. 2018 07 18; 7. View Abstract
  35. Treatment of autosomal dominant hearing loss by in vivo delivery of genome editing agents. Nature. 2018 01 11; 553(7687):217-221. View Abstract
  36. Emerging Gene Therapies for Genetic Hearing Loss. J Assoc Res Otolaryngol. 2017 Oct; 18(5):649-670. View Abstract
  37. Generation of inner ear organoids containing functional hair cells from human pluripotent stem cells. Nat Biotechnol. 2017 06; 35(6):583-589. View Abstract
  38. A synthetic AAV vector enables safe and efficient gene transfer to the mammalian inner ear. Nat Biotechnol. 2017 03; 35(3):280-284. View Abstract
  39. Gene therapy restores auditory and vestibular function in a mouse model of Usher syndrome type 1c. Nat Biotechnol. 2017 03; 35(3):264-272. View Abstract
  40. Are TMCs the Mechanotransduction Channels of Vertebrate Hair Cells? J Neurosci. 2016 10 26; 36(43):10921-10926. View Abstract
  41. RNA Interference Prevents Autosomal-Dominant Hearing Loss. Am J Hum Genet. 2016 06 02; 98(6):1101-1113. View Abstract
  42. Functional development of mechanosensitive hair cells in stem cell-derived organoids parallels native vestibular hair cells. Nat Commun. 2016 05 24; 7:11508. View Abstract
  43. Plug-N-Play: Mechanotransduction Goes Modular. Neuron. 2016 Mar 16; 89(6):1128-1130. View Abstract
  44. Recessive mutations of TMC1 associated with moderate to severe hearing loss. Neurogenetics. 2016 Apr; 17(2):115-123. View Abstract
  45. TMC1 and TMC2 Localize at the Site of Mechanotransduction in Mammalian Inner Ear Hair Cell Stereocilia. Cell Rep. 2015 Sep 08; 12(10):1606-17. View Abstract
  46. The molecules that mediate sensory transduction in the mammalian inner ear. Curr Opin Neurobiol. 2015 Oct; 34:165-71. View Abstract
  47. Tmc gene therapy restores auditory function in deaf mice. Sci Transl Med. 2015 Jul 08; 7(295):295ra108. View Abstract
  48. Transmembrane channel-like (TMC) genes are required for auditory and vestibular mechanosensation. Pflugers Arch. 2015 Jan; 467(1):85-94. View Abstract
  49. Sound strategies for hearing restoration. Science. 2014 May 09; 344(6184):1241062. View Abstract
  50. Mechanotransduction and hyperpolarization-activated currents contribute to spontaneous activity in mouse vestibular ganglion neurons. J Gen Physiol. 2014 Apr; 143(4):481-97. View Abstract
  51. TMC function in hair cell transduction. Hear Res. 2014 May; 311:17-24. View Abstract
  52. Deletion of PDZD7 disrupts the Usher syndrome type 2 protein complex in cochlear hair cells and causes hearing loss in mice. Hum Mol Genet. 2014 May 01; 23(9):2374-90. View Abstract
  53. A Gata3-Mafb transcriptional network directs post-synaptic differentiation in synapses specialized for hearing. Elife. 2013 Dec 10; 2:e01341. View Abstract
  54. Functional contributions of HCN channels in the primary auditory neurons of the mouse inner ear. J Gen Physiol. 2013 Sep; 142(3):207-23. View Abstract
  55. TMC1 and TMC2 are components of the mechanotransduction channel in hair cells of the mammalian inner ear. Neuron. 2013 Aug 07; 79(3):504-15. View Abstract
  56. Gene therapy for deaf mice goes viral. Mol Ther. 2012 Oct; 20(10):1836-7. View Abstract
  57. The mechanosensory structure of the hair cell requires clarin-1, a protein encoded by Usher syndrome III causative gene. J Neurosci. 2012 Jul 11; 32(28):9485-98. View Abstract
  58. The function and molecular identity of inward rectifier channels in vestibular hair cells of the mouse inner ear. J Neurophysiol. 2012 Jul; 108(1):175-86. View Abstract
  59. Mechanotransduction in mouse inner ear hair cells requires transmembrane channel-like genes. J Clin Invest. 2011 Dec; 121(12):4796-809. View Abstract
  60. HCN channels expressed in the inner ear are necessary for normal balance function. J Neurosci. 2011 Nov 16; 31(46):16814-25. View Abstract
  61. Polycystin-1 is required for stereocilia structure but not for mechanotransduction in inner ear hair cells. J Neurosci. 2011 Aug 24; 31(34):12241-50. View Abstract
  62. Gipc3 mutations associated with audiogenic seizures and sensorineural hearing loss in mouse and human. Nat Commun. 2011 Feb 15; 2:201. View Abstract
  63. Development and regeneration of sensory transduction in auditory hair cells requires functional interaction between cadherin-23 and protocadherin-15. J Neurosci. 2010 Aug 25; 30(34):11259-69. View Abstract
  64. HCN channels are not required for mechanotransduction in sensory hair cells of the mouse inner ear. PLoS One. 2010 Jan 07; 5(1):e8627. View Abstract
  65. A quantitative analysis of the spatiotemporal pattern of transient receptor potential gene expression in the developing mouse cochlea. J Assoc Res Otolaryngol. 2010 Mar; 11(1):27-37. View Abstract
  66. Differentiation of neurons from neural precursors generated in floating spheres from embryonic stem cells. BMC Neurosci. 2009 Sep 24; 10:122. View Abstract
  67. Tonotopic gradient in the developmental acquisition of sensory transduction in outer hair cells of the mouse cochlea. J Neurophysiol. 2009 Jun; 101(6):2961-73. View Abstract
  68. A mouse model for nonsyndromic deafness (DFNB12) links hearing loss to defects in tip links of mechanosensory hair cells. Proc Natl Acad Sci U S A. 2009 Mar 31; 106(13):5252-7. View Abstract
  69. Can neurosphere production help restore inner ear transduction? Proc Natl Acad Sci U S A. 2009 Jan 06; 106(1):8-9. View Abstract
  70. Gene transfer in human vestibular epithelia and the prospects for inner ear gene therapy. Laryngoscope. 2008 May; 118(5):821-31. View Abstract
  71. Sensory transduction and adaptation in inner and outer hair cells of the mouse auditory system. J Neurophysiol. 2007 Dec; 98(6):3360-9. View Abstract
  72. Dominant-negative inhibition of M-like potassium conductances in hair cells of the mouse inner ear. J Neurosci. 2007 Aug 15; 27(33):8940-51. View Abstract
  73. Differential distribution of stem cells in the auditory and vestibular organs of the inner ear. J Assoc Res Otolaryngol. 2007 Mar; 8(1):18-31. View Abstract
  74. Heterogeneous potassium conductances contribute to the diverse firing properties of postnatal mouse vestibular ganglion neurons. J Neurophysiol. 2006 Nov; 96(5):2364-76. View Abstract
  75. The very large G-protein-coupled receptor VLGR1: a component of the ankle link complex required for the normal development of auditory hair bundles. J Neurosci. 2006 Jun 14; 26(24):6543-53. View Abstract
  76. Physical and functional interaction between protocadherin 15 and myosin VIIa in mechanosensory hair cells. J Neurosci. 2006 Feb 15; 26(7):2060-71. View Abstract
  77. Fast adaptation in vestibular hair cells requires myosin-1c activity. Neuron. 2005 Aug 18; 47(4):541-53. View Abstract
  78. Developmental acquisition of voltage-dependent conductances and sensory signaling in hair cells of the embryonic mouse inner ear. J Neurosci. 2004 Dec 08; 24(49):11148-59. View Abstract
  79. TRPA1 is a candidate for the mechanosensitive transduction channel of vertebrate hair cells. Nature. 2004 Dec 09; 432(7018):723-30. View Abstract
  80. Developmental acquisition of sensory transduction in hair cells of the mouse inner ear. Nat Neurosci. 2003 Oct; 6(10):1019-20. View Abstract
  81. Transduction and adaptation in sensory hair cells of the mammalian vestibular system. Gravit Space Biol Bull. 2003 Jun; 16(2):61-70. View Abstract
  82. Auditory amplification: outer hair cells pres the issue. Trends Neurosci. 2003 Mar; 26(3):115-7. View Abstract
  83. Viral-mediated gene transfer to study the molecular physiology of the Mammalian inner ear. Audiol Neurootol. 2002 May-Jun; 7(3):157-60. View Abstract
  84. Myosin-I isozymes in neonatal rodent auditory and vestibular epithelia. J Assoc Res Otolaryngol. 2002 Dec; 3(4):375-89. View Abstract
  85. A chemical-genetic strategy implicates myosin-1c in adaptation by hair cells. Cell. 2002 Feb 08; 108(3):371-81. View Abstract
  86. Two mechanisms for transducer adaptation in vertebrate hair cells. Proc Natl Acad Sci U S A. 2000 Oct 24; 97(22):11730-5. View Abstract
  87. Stimulus processing by type II hair cells in the mouse utricle. Ann N Y Acad Sci. 1999 May 28; 871:15-26. View Abstract
  88. Biology in pictures. A sense of colour. Curr Biol. 1999 May 20; 9(10):R351. View Abstract
  89. Functional expression of exogenous proteins in mammalian sensory hair cells infected with adenoviral vectors. J Neurophysiol. 1999 Apr; 81(4):1881-8. View Abstract
  90. Ion channel defects in hereditary hearing loss. Neuron. 1999 Feb; 22(2):217-9. View Abstract
  91. Mechanoelectrical transduction and adaptation in hair cells of the mouse utricle, a low-frequency vestibular organ. J Neurosci. 1997 Nov 15; 17(22):8739-48. View Abstract

Contact Jeffrey Holt