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Karen E. Stevens, PhD

      Karen E. Stevens, PhD


Recent Publications


RC-1 Bldg., Rm. 8105

Phone:  303-724-3005

Email:  Dr. Stevens








Karen E. Stevens, PhD

Associate Professor



Positions and Employment:

Laboratory Research Technician, Dept. Behavioral Sciences and Leadership, United States Air Force Academy, Colorado Springs, CO, 2/80-8/83        

Regular Fellow, Department of Pharmacology, University of Colorado Health Sciences Center, Denver, CO, 4/89-9/91        

Research Pharmacologist, Medical Research Service, VAMC, Denver, CO, 1/91-9/91        

NIMH Post-doctoral Fellow, Dept. Pharmacology, University of Colorado Health Sciences, Denver. CO, 9/91-9/93        

Research Pharmacologist, Medical Research Service, VAMC, Denver, CO, 10/93-10/97    

Instructor, Department of Psychiatry, University of Colorado Health Sciences, Denver, CO 10/93-6/94      

Assistant Professor, Department of Psychiatry, University of Colorado Health Sciences Center, Denver, CO, 6/94-3/02        

Associate Professor, Department of Psychiatry, University of Colorado Health Sciences Center, Denver, CO, 4/02-present   

Research Pharmacologist, Medical Research Service, VAMC, Denver, CO, 7/98-present   



Phi Sigma (Biology Honor Society) - 1973             

Psi Chi (Psychology Honor Society) - 1982             

Irvine Memorial Fellowship - 1984             

NIH/NIDA Predoctoral Fellowship - 1985-1988   

Henry Wood Elliot Memorial Award - 1987             

Regent’s Dissertation Fellowship - 1988             

International Brain Research Organization Travel Award - 1991             

International Congress on Schizophrenia Research Young Investigator Award - 1993             


Teaching Activities:

Department of Craniofacial Biology, School of Dentistry

  • Lecturer, Histology for Dental Hygienists, 1998-2007
  • Lecturer, Review of Histology for Dental Students, 2005-present


Department of Psychiatry, School of Medicine

  • Lecturer, Human Behavior, 2005-present


Clinical Activities:




Selected Peer-Reviewed Publications:

Stevens, K.E., Freedman, R., Collins, A.C., Hall, M., Leonard, S., Marks, M.J., and Rose, G.M.; Genetic correlation of hippocampal auditory evoked response and a-bungarotoxin binding in inbred mouse strains.  Neuropsychopharmacol., 15: 152-162, 1996

Stevens, K.E. and Wear, K.D.;  Normalizing effects of nicotine and a novel nicotinic agonist on hippocampal auditory gating in two animals models, Pharmacol. Biochem. Behav., 57: 869-874, 1997

Stevens, K.E., Johnson, R.G. and Rose, G.M.; Rats reared in social isolation show schizophrenia-like changes in auditory gating, Pharmacol. Biochem. Behav.58: 1031-1036,1997

Stevens, K.E., Kem, W.R., Mahnir, V. and Freedman, R.; Selective a7 nicotinic agonists normalize inhibition of auditory response in DBA mice, Psychopharmacol. 136:320-327, 1998

Lijam, N., Paylor, R., McDonald, M.P., Crawley, J.N., Deng, C.-X., Herrup, K., Stevens, K.E., Maccaferri, G., McBain, C.J.,Sussman, D.J. and Wynshaw-Boris, A., Social interaction and sensorimotor gating abnormalities in mice lacking DV/1, Cell 90: 895-905, 1997

Johnson, R.G., Stevens, K.E., and Rose, G.M.  5HT2 receptor activation normalizes amphetamine-induced auditory filtering impairments in the rat, JPET , 285: 643-650, 1998

Adams, C.E. and Stevens, K.E.  Inhibition of nitric oxide synthase disrupts inhibitory gating of auditory responses in rat hippocampus.  JPET, 287: 760-765, 1998

Stevens, K.E., Kem, W.R. and Freedman, R.  Selective a7 nicotinic receptor stimulation normalizes chronic cocaine-induced loss of hippocampal sensory inhibition in C3H mice.  Biol. Psyhiat., 46:1443-1450, 1999.

Adams, C.E., Stevens, K.E., Kem W.R. and Freedman, R.  Inhibition of nitric oxide synthase prevents a7 nicotinic receptor-mediated restoration of inhibitory auditory gating in rat hippocampus.  Brain Res. 877:235-244, 2000

Freedman, R., Adams, C.E., Alder, L.E., Bickford, P.C., Gault, J., Harris, J.C., Nagamoto, H.T., Olincy, A., Ross, R.G., Stevens, K.E., Waldo, M. and Leonard, S.  Inhibitory neurophysiological deficit as a phenotype for genetic investigation of schizophrenia. Am J Medical Genetics (Semin Med Genet) 97:58-64, 2000

de Bruin, N.M.W.J., Ellenbroek, B.A., van Luijtelaar, E.L.J.M., Cools, A.R. and Stevens, K.E.  Hippocampal and cortical sensory gating in rats: Effects of quinpirole microinjections in nucleus accumbens core and shell.  Neuroscience, 105:169-180 2001

Simosky, J.K., Stevens, K.E., Kem, W.R. and Freedman, R.  Intragastric DMXB-A, an a7 nicotinic agonist, improves deficient sensory inhibition in DBA/2 mice.  Biol. Psychiat. (in press) 2001

Stevens, K.E., Bullock, A.E. and Collins, A.C.  Chronic corticosterone treatment alters sensory gating in C3H mice.  Pharmacol. Biochem. Behav., 69:359-366, 2001

Simosky, J.K., Stevens, K.E. and Freedman, R.  Nicotinic agonists and psychosis.  Current Drug Targets: CNS and Neurological Disorders, 1: 149-162, 2002

Simosky, J.K., Stevens, K.E., Adler, L.E. and Freedman, R.  Clozapine  improves deficient inhibitory auditory processing in DBA/2 mice, via a nicotinic cholinergic mechanism.  Psychopharmacology 165: 386-396, 2003

O’Neill, H.C., Reiger, K., Kem, W.R. and Stevens, K.E.  DMXB, an a7 nicotinic agonist, normalizes auditory gating in isolation reared rats.  Psychopharmacology , 169: 332-339, 2003

O’Neill, H.C., Schmitt, M.P. and Stevens, K.E.  Lithium alters measures of auditory gating in two strains of mice.  Biol. Psychiat. 54: 847-853, 2003

Freedman R. Olincy A. Ross RG. Waldo MC. Stevens KE. Adler LE. Leonard S. The genetics of sensory gating deficits in schizophrenia. Current Psychiatry Reports. 5: 155-61, 2003.

Koike K., Hashimoto K., Taka N., Shimizu E., Komatsu N., Watanabe H., Nakazato M.,  Okamura N., Stevens K.E., Freedman R. and  Iyo M. Tropisetron improves deficits of auditory sensory P50 suppression in schizophrenic patients.  Schizophrenia Res. 76: 67-72, 2005

Hashimoto K., Iyo M., Freedman R and Stevens K.E.  Tropisetro improved deficient inhibitory auditory processing in DBA/2 mice: Role of a7 nicotinic acetylcholine receptors.  Psychopharmacol. (in press) 2005.

Olincy A., Harris J.G., Johnson L.L., Pender V., Kongs S., Allensworth D., Ellis J., Zerbe G.O., Leonard S., Stevens K.E., Stevens J.O., Martin L., Alder L.E., Soti F., Kem W.R. and Freedman R.  Proof-of-principle trial of an a7- nicotinic cholinergic agonist for neurocognitive dysfunction in schizophrenia.  Arch Gen Psychiatry 63:630-638, 2006

Swerdlow NR, Geyer MA, Shoemaker JM, Light GA, Braff DL, Stevens KE, Sharp R, Breier M, Neary A and Auerbach PP. Convergence and divergence in the neurochemical regulation of prepulse inhibition of startle and N40 suppression in rats.  Neuropsychopharmacol. 31:506-515, 2006

Stevens, KE, O'Neill, HC, Rose GM, and Luthman J.  The 5-HT1A receptor active compounds (R)-8-OH-DPAT and (S)-UH-301 modulate auditory evoked EEG responses in rats.  Amino Acids 31:365-375, 2006

Adams, CE, and Stevens, KE.  Evidence for a role of nicotinic acetylcholine receptors in schizophrenia.  Frontiers in Biology 12:4755-4772, 2007

Ng, HJ, Whittemore, ER, Tran, MB, Hogenkamp, DK, Broide, RS, Johnstone, TB, Zheng, L, Stevens, KE and Gee, KW.  A nootropic a7 nicotinic receptor allosteric modulator derived from GABAA receptor modulators.  PNAS 104:8059-8064, 2007

Olincy, A and Stevens, KE.  Treating the symptoms of schizophrenia with an a7 nicotinic agonist:  from mice to men.  Molecular Pharmacology, 74(8):1192-201. 2007

Stevens, KE, Adams, CE, Yonchek, J, Hickel, C, Danielson, J, and Kisley, MA.  Permanent improvement in deficient sensory inhibition in DBA/2 mice with increased perinatal choline. Psychopharmacol., 198:413-20, 2008.

Abrams, DJ, Zheng, L, Choo, K, Yang, JJ, Wei, W, Anchordoquy TJ, Zawia NH, and Stevens, K.E.   An Initial Animal Proof-of-Concept Study for Central Administration of Clozapine to Schizophrenia Patients.  Schizophr Res, 100:86-96 ,2008

Adams, CE, Yonchek JC, Zheng L, Collins AC and Stevens K.E.  Altered hippocampal circuit function in C3H a7 receptor null mutant heterozygous mice.  Brain Res, 1194:138-145, 2008

Freedman R, Olincy A, Buchanan RW, Harris JG, Gold JM, Johnson L, Allensworth D, Guzman-Bonilla A, Clement B, Vall MP, Kutnick J, Pender V, Martin LF, Stevens KE, Wagner BD, Zerbe ZO, Soti F and Kem WR.  Initial Phase 2 trial of a nicotinic agonist in schizophrenia.  Am J Psychiat 165:1040-47, 2008

Wildeboer, K.M. and Stevens, K.E  Stimulation of the a4b2 nicotinic receptor by 5-IA-85380 improves auditory gating in DBA/2 mice.  Am J Psychiat 165:1040-47, 2008

Simosky, JK, Freedman, R and Stevens, KE.  Olanzapine improves deficient sensory inhibition in DBA/2 mice.  Brain Res, 1233:129-136 , 2008

Stevens KE, Adams CE, Mellott TJ, Robbins E, and Kisley MA.  Perinatal choline deficiency produces abrnormal sensory inhibition in Sprague-Dawley rates. Brain Res, 1237:84-90, 2008


Grants and Contracts:

NIMH 1 RO1 MH073725-01 (PI –KE Stevens), 8/06-7/09 (no-cost extension 7/10)

“Gestational choline levels and sensory inhibition”

Gestational choline supplementation in DBA/2 mice produces permanent improvement in sensory inhibition, improves contextual fear conditioning and novel object recognition.


NIMH 1 RO1 MH50787-01 (PI – L Adler), 8/94-5/09

“Atypical antipsychotics and P50 sensory gating”

Co-investigator.  Major findings:  The antiemetic, tropisetron, which is a 5HT3 antagonist and an 7 nicotinic agonist, improves sensory inhibition in DBA/2 mice through both 7 and  nicotinic receptor mechanisms.  Similarly the antiemetic ondansetron also improves sensory inhibition when administered acutely, but not chronically.


VA Medical Center, VAMC Merit Review Grant  (PI –KE Stevens), 10/08-9/12 

“Nicotine interference with clozapine efficacy in schizophrenia treatment”

New grant, no findings yet.