- Biological processes underlying learning and memory
- Producing animal models of human psychopathology
- Neural substrates of fear conditioning
My work concerns the biological substrates of memory, fear, and anxiety, and drug dependence. Fears can be acquired extremely rapidly and once acquired, can last a lifetime. I use Pavlovian conditioning paradigms to produce fearful memories in rats. To test for the presence and strength of those memories, I measure the startle reflex, the size of which is elevated when a rat (or other mammal, including human) is afraid.
"Fear-potentiated startle" provides us with a tool to identify brain structures, and to study pharmacological and molecular mechanisms involved in different aspects of the formation and retrieval of fearful memories. Moreover, dramatic elevations in startle accompany certain forms of anxiety disorder and the anxiety-related symptoms of drug withdrawal. Thus, understanding the mechanisms through which startle is potentiated provides insights into the pathophysiology and treatment of anxiety and drug abuse.
(For a comprehensive list of recent publications, refer to PubMed, a service provided by the National Library of Medicine.)
- Kennedy BC, Tran PV, Kohli M, Maertens JJ, Gewirtz JC, Georgieff MK. Beneficial effects of postnatal choline supplementation on long-term neurocognitive deficit resulting from fetal-neonatal iron deficiency. Behav Brain Res. 2018;336:40-43.
- Pisansky MT, Hanson LR, Gottesman II, Gewirtz JC. Oxytocin enhances observational fear in mice. Nat Commun. 2017 Dec 13;8(1):2102.
- Pisansky MT, Young AE, O'Connor MB, Gottesman II, Bagchi A, Gewirtz JC. Mice lacking the chromodomain helicase DNA-binding 5 chromatin remodeler display autism-like characteristics. Transl Psychiatry. 2017 Jun 13;7(6):e1152.
- Kennedy BC, Kohli M, Maertens JJ, Marell PS, Gewirtz JC. Conditioned object preference: an alternative approach to measuring reward learning in rats. Learn Mem. 2016;23:623-630.
- Kennedy BC, Dimova JG, Dakoji S, Yuan LL, Gewirtz JC, Tran PV. Deletion of novel protein TMEM35 alters stress-related functions and impairs long-term memory in mice. Am J Physiol Regul Integr Comp Physiol. 2016;311:R166-178.
- Tran PV, Kennedy BC, Pisansky MT, Won KJ, Gewirtz JC, Simmons RA, Georgieff MK. Prenatal choline supplementation diminishes early-life iron deficiency-induced reprogramming of molecular networks associated with behavioral abnormalities in the adult rat hippocampus. J Nutr. 2016;146:484-93.
- Rao R, Ennis K, Mitchell EP, Tran PV, Gewirtz JC. Recurrent moderate hypoglycemia suppresses brain-derived neurotrophic factor expression in the prefrontal cortex and impairs sensorimotor gating in the posthypoglycemic period in young rats. Dev Neurosci. 2016;38:74-82.
- Sweis BM, Bachour SP, Brekke JA, Gewirtz JC, Sadeghi-Bazargani H, Hevesi M, Divani AA. A modified beam-walking apparatus for assessment of anxiety in a rodent model of blast traumatic brain injury. Behav Brain Res. 2016;296:149-156.
- Engelmann JM, Versace F, Gewirtz JC, Cinciripini PM. Individual differences in brain responses to cigarette-related cues and pleasant stimuli in young smokers. Drug Alcohol Depend. 2016;163:229-35.
- McBrayer ZL, Dimova J, Pisansky MT, Sun M, Beppu H, Gewirtz JC, O'Connor MB. Forebrain-specific loss of BMPRII in mice reduces anxiety and increases object exploration.PLoS One. 2015 Oct 7;10(10):e0139860.
- Radke AK, Gewirtz JC, Carroll ME. Effects of age, but not sex, on elevated startle during withdrawal from acute morphine in adolescent and adult rats. Behav Pharmacol. 2015;26:485-488.
- Kennedy BC, Dimova JG, Siddappa AJ, Tran PV, Gewirtz JC, Georgieff MK. Prenatal choline supplementation ameliorates the long-term neurobehavioral effects of fetal-neonatal iron deficiency in rats. J Nutr. 2014;144:1858-1865.
- Hamilton KL, Harris AC, Gewirtz JC. Affective and neuroendocrine effects of withdrawal from chronic, long-acting opiate administration. Brain Res. 2013;1538:73-82.
- Pisansky MT, Wickham RJ, Su J, Fretham S, Yuan LL, Sun M, Gewirtz JC, Georgieff MK. Iron deficiency with or without anemia impairs prepulse inhibition of the startle reflex. Hippocampus. 2013;23:952-62.
- Blegen MB, Kennedy BC, Thibert KA, Gewirtz JC, Tran PV, Georgieff MK. Multigenerational effects of fetal-neonatal iron deficiency on hippocampal BDNF signaling. Physiol Rep. 2013 Oct;1(5):e00096.
- Radke AK, Holtz NA, Gewirtz JC, Carroll ME. Reduced emotional signs of opiate withdrawal in rats selectively bred for low (LoS) versus high (HiS) saccharin intake. Psychopharmacology (Berl). 2013;227:117-26.
- Rothwell PE, Thomas MJ, Gewirtz JC. Protracted manifestations of acute dependence after a single morphine exposure. Psychopharmacology (Berl). 2012;219:991-8
- Radke AK, Rothwell PE, Gewirtz JC. An anatomical basis for opponent process mechanisms of opiate withdrawal. J Neurosci. 2011;31:7533-9.
Former Graduate Students:
Marc Pisansky (Ph.D. 2016, Neuroscience, University of Minnesota).
Bruce Kennedy (Ph.D. 2016, Neuroscience, University of Minnesota).
Anna Radke (Ph.D. 2011, Neuroscience, University of Minnesota).