Jill C. Fehrenbacher, PhD

Assistant Professor of Pharmacology and Toxicology

Research Interest 

The broad goal of my research is to examine the role of estradiol in inflammatory hyperalgesia.  My laboratory specifically focuses on two main areas: (I) elucidating the mechanisms by which estradiol sensitizes trigeminal neurons and (II) elucidating the role of the enzymes involved in estradiol biosynthesis in peripheral tissues. The trigeminal system has been selected to test these hypotheses since striking gender differences are reported for several cranio- and orofacial pain conditions (eg., Dao and LeResche, 2000).




B.S. Biology
University of Southern Indiana
Evansville, Indiana


PhD Pharmacology
Indiana University Graduate School Indianapolis, Indiana
Mentor: Michael R. Vasko, PhD

2005 - 2009

Research Fellow
University of Texas Health Science Center
San Antonio, Texas
Laboratory of Dr. Kenneth Hargreaves



Maria Yeung Dental Research Award
University of Texas Health Science Center
San Antonio, Texas


Dental Science Symposiumn
1st Place, Postdoctoral Division
University of Texas Health Science Center
San Antonio, Texas


Center for Biomedical Neuroscience
Annual Retreat
First Place Postdoctoral Division

2004 - 2005

K.K. Chen Fellowship
Indiana University School of Medicine
Indianapolis, Indiana


Graduate Student Educational Enhancement Award
Indiana University Graduate School
Indianapolis, Indiana

1995 - 1999

Scholastic Excellence Award
University of Southern Indiana
Evansville, Indiana

1998 - 1999

Bertram Bennett Athletic and Academic Excellence Scholarship
University of  Southern Indiana
Evansville, Indiana

Epidemiological evidence indicates a higher prevalence of painful disorders in females than in males. The Fehrenbacher laboratory is interested in investigating the physiological  basis for these 

observations. Particularly, we are examining the effects of acute and chronic exposure of estrogens, testosterone and progesterone on the sensitivity of nociceptive sensory neurons. 

Our studies range from cellular and molecular studies on single neurons to whole animal experiments and clinical trials. A variety of methods are used to answer our questions about sensory neurons including behavioral, pharmacological, biochemical, anatomical and molecular biological techniques. These include in vivo microdialysis of normal and injured tissues in animals, behavioral assays of spontaneous, thermal and mechanical nociception, in vitro superfusion of neural cultures and tissues obtained by surgical biopsy collection from humans and animals, real-time RT-PCR, immunoblotting, in situ hybridization and immunohistochemistry, and collection of patient DNA and postoperative pain reports to determine correlations between polymorphisms of genes of interest and pain. 

Selected Publications

  • Park KA, Fehrenbacher JC, Thompson EL, Duarte DB, Hingtgen CM, Vasko MR. Signaling pathways that mediate nerve growth factor-induced increase in expression and release of calcitonin gene-related peptide from sensory neurons. Neuroscience. 2010 Dec 15;171(3):910-23. Epub 2010 Sep 24. PubMed PMID: 20870010; PubMed Central PMCID: PMC2987548.

  • Fehrenbacher JC, Sun XX, Locke EE, Henry MA, Hargreaves KM. Capsaicin-evoked iCGRP release from human dental pulp: a model system for the study of peripheral  neuropeptide secretion in normal healthy tissue. Pain. 2009 Aug;144(3):253-61. Epub 2009 May 9. PubMed PMID: 19428185; PubMed Central PMCID: PMC2759350.

  • Fehrenbacher JC, Loverme J, Clarke W, Hargreaves KM, Piomelli D, Taylor BK. Rapid pain modulation with nuclear receptor ligands. Brain Res Rev. 2009 Apr;60(1):114-24. Epub 2008 Dec 31. Review. PubMed PMID: 19162071.

  • Jeske NA, Diogenes A, Ruparel NB, Fehrenbacher JC, Henry M, Akopian AN, Hargreaves KM. A-kinase anchoring protein mediates TRPV1 thermal hyperalgesia through PKA phosphorylation of TRPV1. Pain. 2008 Sep 15;138(3):604-16. Epub 2008  Apr 1. PubMed PMID: 18381233; PubMed Central PMCID: PMC2593399.

  • Patwardhan AM, Diogenes A, Berg KA, Fehrenbacher JC, Clarke WP, Akopian AN, Hargreaves KM. PAR-2 agonists activate trigeminal nociceptors and induce functional competence in the delta opioid receptor. Pain. 2006 Nov;125(1-2):114-24. Epub 2006 Jun 14. PubMed PMID: 16781076.

  • Zhang YH, Fehrenbacher JC, Vasko MR, Nicol GD. Sphingosine-1-phosphate via activation of a G-protein-coupled receptor(s) enhances the excitability of rat sensory neurons. J Neurophysiol. 2006 Sep;96(3):1042-52. Epub 2006 May 24. PubMed PMID: 16723416.

  • Fehrenbacher JC, Burkey TH, Nicol GD, Vasko MR. Tumor necrosis factor alpha and interleukin-1beta stimulate the expression of cyclooxygenase II but do not alter prostaglandin E2 receptor mRNA levels in cultured dorsal root ganglia cells. Pain. 2005 Jan;113(1-2):113-22. PubMed PMID: 15621371.

  • Fehrenbacher JC, Taylor CP, Vasko MR. Pregabalin and gabapentin reduce release of substance P and CGRP from rat spinal tissues only after inflammation or activation of protein kinase C. Pain. 2003 Sep;105(1-2):133-41. PubMed PMID: 14499429.

Department of Pharmacology and Toxicology | 635 Barnhill Drive, MS A401 | Indianapolis, IN 46202