Helmstetter Lab - Research

Our work is aimed at understanding the neural systems underlying complex psychological phenomena like perception, learning, memory and emotion. The research currently being conducted in my laboratory addresses these issues at several levels of analysis using laboratory animals and human volunteers as subjects.

A number of research projects are currently underway. The majority of these use basic associative learning paradigms to analyze how the brain encodes and stores new information. We are interested in how the process of memory formation works from molecular biology and genomics through human cognitive neuroscience. The emphasis tends to be on fundamental mechanisms rather than on diseases, pathology, or clinical issues.

Recent studies in the rat lab have focused on the control of gene expression and the need for new protein synthesis in neurons during the period immediately following new learning. We are interested in the dynamics of gene expression changes throughout the brain during memory consolidation and the processes by which long term memories remain stable over long periods.

Our human work uses functional magnetic resonance imaging (fMRI) to "map" changes in brain activity during learning and remembering. Here our focus has been on understanding how different circuits in the brain are responsible for "conscious" or explicit memories versus "unconscious" or implicit memories formed by the same event. We've also been looking at how brain patterns change when learning about safety as opposed to danger and when recalling newly formed memories compared to events that happend in the relativity distant past.

Other current projects include studies on molecular mechanisms of stress, modulation pain sensitivity, functional imaging in laboratory animals at high magnetic field strength, molecular biology of learning in zebrafish, and several other interesting and important questions.

More information about the lab can be found on Dr. Helmstetter's web page and on the Psychology and Neuroscience sites. Also come visit us at our posters this year at the Society for Neuroscience meeting.

Selected Publications

Cheng, D. T., Richards, J., & Helmstetter, F. J. (2007). Activity in the human amygdala corresponds to early, rather than late period autonomic responses to a signal for shock. Learn Mem, 14(7), 485-490. PDF

Parsons, R.G., Gafford, G.M., & Helmstetter, F.J. (2006) Translational control via the mamilian target of rapamycin pathway is critical for the formation and stability of long term fear memory in amygdala neurons. Journal of Neuroscience, 26(50): 12977-12983. PDF

Cheng, D. T., Knight, D. C., Smith, C. N., & Helmstetter, F.J. (2006) Human amygdala activity during the expression of fear responses. Behavioral Neuroscience, 120: 1187-1195. PDF

Parsons, R.G., Riedner, B.A., Gafford, G.M., & Helmstetter, F.J. (2006) The formation of auditory fear memory requires the synthesis of protein and mRNA in the auditory thalamus. Neuroscience, 141: 1163-1170. PDF

Parsons, R.G., Gafford, G.M., Baruch, D.E., Riedner, B.A., & Helmstetter, F.J. (2006) Long term stability of fear memory depends on the synthesis of protein but not mRNA in the amygdala. European Journal of Neuroscience, 23:1853-1859. PDF

Shin, M.S. & Helmstetter, F.J. (2005) Antinociception following application of DAMGO to the basolateral amygdala results from a direct interaction of DAMGO with mu opioid receptors in the amygdala. Brain Research. PDF

Gafford, G.M., Parsons, R.G. & Helmstetter, F.J. (2005) Effects of post training hippocampal injections of midazolam on fear conditioning. Learning & Memory, 12:573-578 PDF

Knight, D.C., Smith, C.N., Cheng, D.T., Stein, E.A., & Helmstetter, F.J. (2004) Amygdala and huppocampal activity during acquisition and extinction of human fear conditioning. Cognitive, Affective, and Behavioral Neuroscience, 4(3): 317-325. PDF

Baruch, D.E., Swain, R.A., & Helmstetter, F.J. (2004) Effects of exercise on Pavlovian fear conditioning. Behavioral Neuroscience, Oct 118(5):1123-1127. PDF

Knight, D.C., Cheng, D.T., Smith, C.N., Stein, E.A., & Helmstetter, F.J. (2004) Neural substrates mediating human delay and trace fear conditioning. Journal of Neuroscience, 24(1):218-228. PDF

Cheng, D.T., Knight, D.C., Smith, C.N., Stein, E.A., Helmstetter, F.J. (2003) Functional MRI of human amygdala activity during Pavlovian fear conditioning: stimulus processing versus response expression. Behavioral Neuroscience, 117(1):3-10. PDF

Bailey, D.J., Tetzlaff, J.E., Cook, J.M., He, X., & Helmstetter, F.J. (2002) Effects of hippocampal injections of a novel ligand selective for the alpha 5 beta 2 gamma 2 subunits of the GABA/benzodiazepine receptor on Pavlovian conditioning. Neurobiology of Learning and Memory, 78(1):1-10.

Kocorowski, L.H., and Helmstetter, F.J. (2001) Calcitonin gene-related peptide released within the amygdala is involved in Pavlovian auditory fear conditioning. Neurobiology of Learning and Memory, 75(2):149-63.

Foo, H., and Helmstetter, F.J. (2000) Activation of kappa opioid receptors in the rostral ventromedial medulla blocks stress-induced antinociception. Neuroreport, 11(15):3349-52. PDF

Tershner, S.A., and Helmstetter, F.J. (2000) Antinociception produced by mu opioid receptor activation in the amygdala is partly dependent on activation of mu opioid and neurotensin receptors in the ventral periaqueductal gray. Brain Research, 865(1):17-26. PDF

Foo, H., and Helmstetter, F.J. (2000) Expression of antinociception in response to a signal for shock is blocked after selective downregulation of mu-opioid receptors in the rostral ventromedial medulla. Brain Research: Molecular Brain Research. 76(2):282-8. PDF

Knight, D.C., Smith. C.N., Stein, E.A., & Helmstetter, F.J. (1999) Functional MRI of human Pavlovian fear conditioning: patterns of activation as a function of learning. Neuroreport; 10(17): 3665-70. PDF

Foo, H., and Helmstetter, F.J. (1999) Hypoalgesia elicited by a conditioned stimulus is blocked by a mu, but not a delta or a kappa, opioid antagonist injected into the rostral ventromedial medulla. Pain, 83(3): 427-31. PDF