Katherine Rennie, PhD

Recognitions

• James A. Shannon Director’s Award, NIDCD (2007)
• Research Career Enhancement Award, American Physiological Society (2003)
• Gordon Res. Conference Young Investigator Award, NASA-NSF (1996)
• Dale and Rushton Fund Award, Physiological Society (1988)

Research Interests

This laboratory's research is focused on hair cells of the vestibular system. The vestibular system of the inner ear senses accelerations of the head and interacts with other systems to produce the sensation of balance. It is estimated that more than one third of adults in the US experience vestibular dysfunction at some time in their life. However the mechanisms underlying normal and abnormal processing of vestibular sensory signals are not well understood. Our research aims to elucidate how signals are processed in the peripheral vestibular system using rodent models. Mechanoreceptive hair cells in the vestibular periphery convert tiny mechanical displacements of the hair cell bundle into electrical signals which are transmitted by vestibular afferent nerves to the brain. Type I and type II hair cells are found in the vestibular systems of mammals, birds and reptiles. The two hair cell types differ in several respects including their innervation characteristics. Whereas bouton afferent nerve terminals make synaptic contact with a small portion of the type II hair cell basolateral membrane, calyx-shaped afferent terminals engulf the basolateral surface of one or more type I hair cells. In order to understand how signals are transformed from a mechanical stimulus at the type I hair cell bundle into electrical activity of calyx afferents we use electrophysiological (patch clamp), molecular and mathematical modeling approaches. We have identified several different types of potassium channels in vestibular cells and are currently assessing their modulation by candidate efferent transmitters and ototoxic drugs. It is hoped that results from these studies will clarify some of the mechanisms underlying vestibular disorders.

Publications

• Mohamed, N. M. M., Meredith, F. L. Rennie, K. J. Inhibition of ionic currents by fluoxetine in vestibular calyces in different epithelial loci. Int. J. Mol. Sci. 2024 25(16), 8801 doi.org/10.3390/ijms25168801.
• Al-Amin M, Vu T, Gehrke B, Dondzillo A, Meredith F, Peng A, Rennie KJ. Age-Related Changes in the Gerbil Peripheral Vestibular System. J Vestibular Res 33(4):31, 2023.
• Meredith FL, Vu TA, Gehrke B, Benke TA, Dondzillo A, Rennie KJ. Expression of hyperpolarization-activated current (I(h)) in zonally defined vestibular calyx terminals of the crista. J Neurophysiol. 2023 Jun 1;129(6):1468-1481. PubMed PMID: 37198134
• Meredith FL, Brown, N, Rennie KJ. Dopaminergic Inhibition of Sodium Currents in Vestibular Calyces. Assoc. Res. Otolaryngol. 45th mid-winter meeting 2022.
• Gherke B, Meredith FL, Dondzillo A, Vu T, Rennie KJ. Aging and Dysfunction in the Peripheral Vestibular System. ENDURE, Diversity Poster Session, Society for Neuroscience Meeting, 2022.
• https://pubmed.ncbi.nlm.nih.gov/34580582/ Dopaminergic inhibition of Na+ currents in vestibular inner ear afferents Frontiers Neurosci 2021
• Meredith F.L., Rennie K. J. Persistent and resurgent Na+ currents in vestibular calyx afferents. J. Neurophysiol. 124: 510-524, 2020.
• Meredith FL, Dockstader K, Arne A, Rennie KJ. Nav1.6 Channels Mediate Persistent and Resurgent Sodium Currents in Vestibular Calyx Afferent Terminals. J Vestibular Res 29(1):25-26, 2019.
• Meredith, F., Arne A., Dockstader, K and Rennie, K. Nav1.6-mediated currents in early postnatal and mature vestibular calyx afferent terminals. Assoc. Res. Otolaryngol. 42nd mid-winter meeting 2019.
• Meredith FL, Rennie KJ. Regional and Developmental Differences in Na( ) Currents in Vestibular Primary Afferent Neurons. Front Cell Neurosci. 2018;12:423. PubMed PMID: 30487736
• Kirk ME, Meredith FL, Benke TA, Rennie KJ. AMPA receptor-mediated rapid EPSCs in vestibular calyx afferents. J Neurophysiol. 2017 Jun 1;117(6):2312-2323. PubMed PMID: 28298303
• Tung, V, Meredith, F, Rennie, K, Burton, TJ and Camp, AJ. Behavioural and preliminary electrophysiological analysis of the aging mouse vestibular system. Frontiers, Gold Coast Australia, 2016.
• Meredith FL, Rennie KJ. Channeling your inner ear potassium: K( ) channels in vestibular hair cells. Hear Res. 2016 Aug;338:40-51. PubMed PMID: 26836968
• Meredith F.L., Kirk M. E, Rennie K. J. Kv1 channels and neural processing in vestibular afferents. Frontiers in Systems Neuroscience: A Multidisciplinary Approach to designing Sensorimotor Adaptation countermeasures for space exploration missions 9:85 DOI:10.3389/fnsys.2015.00085.
• Meredith FL, Rennie KJ. Zonal variations in K currents in vestibular crista calyx terminals. J Neurophysiol. 2015 Jan 1;113(1):264-76. PubMed PMID: 25343781
• Mann SE, Johnson M, Meredith FL, Rennie KJ. Inhibition of K currents in type I vestibular hair cells by gentamicin and neomycin. Audiol Neurootol. 2013;18(5):317-26. PubMed PMID: 24051519
• Mann S., Johnson M., Meredith F.L., Rennie K. J. Inhibition of K+ currents in type I vestibular hair cells by gentamicin and neomycin (submitted to Audiol Neurotol).
• Mann, S., Johnson, M. Meredith, F. and Rennie, K. Inhibition of K+ Currents in Type I Vestibular Hair Cells by Aminoglycosides. 2012 Neuroscience Retreat, Estes Park.
• Meredith FL, Benke TA, Rennie KJ. Hyperpolarization-activated current (Ih) in vestibular calyx terminals: characterization and role in shaping postsynaptic events (JARO, accepted with minor revisions).
• Meredith, F, Mann, S, and Rennie, K. Characterization of a hyperpolarization-activated current (Ih) in vestibular calyx terminals. Assoc. Res. Otolaryngol. 35th mid-winter meeting (podium presentation) 285, 2012.
• Meredith, F., Li, G., and Rennie, K. An apamin-sensitive K(Ca) current contributes to the AHP in vestibular calyx terminals. Rocky Mountain Regional Neuroscience Group Meeting, 2011 (Best Poster Presenter Award to Frances Meredith).
• Mann, S., Ross, H., Johnson, M. Meredith, F. and Rennie, K. Inhibition of K+ Currents in Type I Vestibular Hair Cells by Aminoglycosides. Assoc. Res. Otolaryngol. 35th mid-winter meeting (podium presentation), 284, 2012.
• Meredith F.L., Benke T.A., Rennie K. J. Hyperpolarization-activated current (Ih) in vestibular calyx terminals: characterization and role in shaping postsynaptic events J Assoc Res Otolaryngol, 13:745-758, 2012.
• Meredith, F. L. Li, G., and Rennie, K. J. Postnatal expression of an apamin-sensitive K(Ca) current in vestibular calyx terminals J. Membr. Biol. 244:81-91, 2011.
• Dhawan, R., Mann, S. E., Meredith, F. L. and Rennie, K. J. K+ currents in isolated vestibular afferent calyx terminals. J Assoc Res Otolaryngol 11:463-476, 2010.
• Meredith F.L., Rennie K. J. Zonal variations in K+ currents in vestibular crista calyx terminals. J. Neurophysiol. DOI: 10.1152/jn.00399.2014.
• Kirk M. E, Meredith F.L., Benke T.A., Rennie K. J. AMPA receptor-mediated rapid EPSCs in vestibular calyx afferents. (J. Neurophysiol. submitted).
• Dopamine decreases voltage-gated sodium currents in vestibular calyx terminals. Meredith FL, Rennie KJ. Vestibular Oriented Research Meeting 2021 (submitted).
• Mohamed, N., Al-Amin M. Meredith, F. L., Kalmanson O, Dondzillo A, Cass, S., Gubbels S, Rennie, K. J. Electrophysiological Properties of Vestibular Hair Cells Isolated from Human Crista. Frontiers in Neurology (accepted). DOI10.3389/fneur.2024.1501914

Professional Memberships

• Association for Research in Otolaryngology, Member
• Society for Neuroscience, Member
• American Physiological Society, Member
• Biophysical Society, Member
• Sigma Xi Scientific Research Society, Elected

Specialty Information

Specialties

• Otolaryngology - Head & Neck Surgery