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A. Catalina Vélez-Ortega, PhD


Office: (859) 323-4344
741 South Limestone Street, Biomedical/Biological Sciences Research Building, Rm: B377, Lexington, KY 40536-0509


  • Assistant Professor, Department of Physiology

College Unit(s)


She / Her

Biography and Education



B.S. in Biomedical Engineering, Antioquia School of Engineering & Health Sciences Institute, Colombia, 2003

M.S. in Biology, University of Antioquia, Colombia, 2009

Ph.D. in Physiology, University of Kentucky, Lexington, KY, 2014


My laboratory is currently working on two main projects:

1. Molecular machinery involved in the activity-dependent plasticity of the stereocilia cytoskeleton:  The inner ear sensory cells (known as hair cells) have specialized microvilli that are groped in highly-organized bundles. These sensory organelles detect sounds or head movements. We previously showed that the actin cytoskeleton within these modified microvilli exhibits activity-dependent remodeling. We are currently studying the molecular mechanisms involved in this novel type of cytoskeleton remodeling by exploring activity-dependent changes to actin dynamics, actin composition, actin filament organization, and several actin-binding proteins.

2. Protection against noise-induced hearing loss mediated by TRPA1 channels: TRPA1 channels are master sensors of tissue damage. In nociceptive neurons, TRPA1 activation triggers pain signals. In the inner ear, TRPA1 function is unknown. We have found that TRPA1 channels can be activated after noise exposure and their activation regulates hearing sensitivity. In this project we are exploring the cellular pathways through which TRPA1 activation leads to changes in hearing sensitivity.

Selected Publications

  1. Large-scale annotated dataset for cochlear hair cell detection and classification. Buswinka CJ, Rosenberg DB, Simikyan RG, Osgood RT, Fernandez K, Nitta H, Hayashi Y, Liberman LW, Nguyen E, Yildiz E, Kim J, Jarysta A, Renauld J, Wesson E, Wang H, Thapa P, Bordiga P, McMurtry N, Llamas J, Kitcher SR, López-Porras AI, Cui R, Behnammanesh G, Bird JE, Ballesteros A, Vélez-Ortega AC, Edge ASB, Deans MR, Gnedeva K, Shrestha BR, Manor U, Zhao B, Ricci AJ, Tarchini B, Basch ML, Stepanyan R, Landegger LD, Rutherford MA, Liberman MC, Walters BJ, Kros CJ, Richardson GP, Cunningham LL, Indzhykulian AA. Sci Data. 2024 Apr 23;11(1):416. PMID: 38653806
  2. Imaging analysis reveals budding of filamentous human metapneumovirus virions and direct transfer of inclusion bodies through intercellular extensions. El Najjar F, Restrepo Castillo S, Moncman CL, Wu CY, Isla E, Velez Ortega AC, Frolenkov GI, Cifuentes-Munoz N, Dutch RE. mBio. 2023 Oct 31;14(5):e0158923. PMID: 37681946 
  3. TRPA1 activation in non-sensory supporting cells contributes to regulation of cochlear sensitivity after acoustic trauma.  Vélez-Ortega AC, Stepanyan R, Edelmann SE, Torres-Gallego S, Park C, Marinkova DA, Nowacki JS, Sinha GP, Frolenkov GI. Nat Commun. 2023 Jun 30;14(1):3871. PMID: 37391431
  4. Stereocilia bundle Imaging with Nanoscale Resolution in Live Mammalian Auditory Hair Cells. Galeano-Naranjo C, Vélez-Ortega AC, Frolenkov GI. JoVE, 2021 (167). PMID: 33554973
  5. Myosin-XVa Controls Both Staircase Architecture and Diameter Gradation of Stereocilia Rows in the Auditory Hair Cell Bundles. Hadi S, Alexander AJ, Vélez-Ortega AC, Frolenkov GI.J Assoc Res Otolaryngol. 2020 Apr;21(2):121-135. PMID: 32152769
  6. Building and repairing the stereocilia cytoskeleton in mammalian auditory hair cells.  Vélez-Ortega AC, Frolenkov GI. Hear Res. 2019; 376:47-57. PMID: 30638948 
  7. Mechanotransduction current is essential for stability of the transducing stereocilia in mammalian auditory hair cells. Vélez-Ortega AC, Freeman MJ, Indzhykulian AA, Grossheim JM, Frolenkov GI. eLife. 2017; 6. PMID: 28350294
  8. Angular Approach Scanning Ion Conductance Microscopy. Shevchuk A, Tokar S, Gopal S, Sanchez-Alonso JL, Tarasov AI, Vélez-Ortega AC, Chiappini C, Rorsman P, Stevens MM, Gorelik J, Frolenkov GI, Klenerman D, Korchev YE. Biophysical journal. 2016; 110(10):2252-65. PMID: 27224490
  9. Visualization of Live Cochlear Stereocilia at a Nanoscale Resolution Using Hopping Probe Ion Conductance Microscopy. Vélez-Ortega AC, Frolenkov GI. Methods in molecular biology (Clifton, N.J.). 2016; 1427:203-21. PMID: 27259929
  10. [Common variable immunodeficiency: Clinical and immunological characterization of patients and homogeneous subgroup definition by means of B lymphocyte subpopulation typing]. Vélez AC, Castaño DM, Gómez RD, Orrego JC, Moncada M, Franco JL. Biomedica : revista del Instituto Nacional de Salud. 2015; 35(1):101-16. PMID: 26148039
  11. Enhanced generation of suppressor T cells in patients with asthma taking oral contraceptives. Vélez-Ortega AC, Temprano J, Reneer MC, Ellis GI, McCool A, Gardner T, Khosravi M, Marti F. The Journal of asthma : official journal of the Association for the Care of Asthma. 2013; 50(3):223-30. PMID: 23259774
  12. Generation of induced regulatory T cells from primary human naïve and memory T cells. Ellis GI, Reneer MC, Vélez-Ortega AC, McCool A, Martí F. Journal of visualized experiments : JoVE. 2012; (62). PMID: 22525890
  13. TRPA1-mediated accumulation of aminoglycosides in mouse cochlear outer hair cells. Stepanyan RS, Indzhykulian AA, Vélez-Ortega AC, Boger ET, Steyger PS, Friedman TB, Frolenkov GI. Journal of the Association for Research in Otolaryngology : JARO. 2011; 12(6):729-40. PMID: 21879401
  14. Somatic mosaicism caused by monoallelic reversion of a mutation in T cells of a patient with ADA-SCID and the effects of enzyme replacement therapy on the revertant phenotype. Moncada-Vélez M, Vélez-Ortega A, Orrego J, Santisteban I, Jagadeesh J, Olivares M, Olaya N, Hershfield M, Candotti F, Franco J. Scandinavian journal of immunology. 2011; 74(5):471-81. PMID: 21671975
  15. Peripherally induced human regulatory T cells uncouple Kv1.3 activation from TCR-associated signaling. Reneer MC, Estes DJ, Vélez-Ortega AC, Norris A, Mayer M, Marti F. European journal of immunology. 2011; 41(11):3170-5. PMID: 21834013