Assistant Professor of Biology

Phone:(405)325-6200
Lab: (405)325-6200
Fax: (405)325-6202

RM/Lab:RH314/314

Christian H. Lemon

Current Research Interests and Subject Areas Available for Graduate Research

My students and I study how the brain processes information. We have a deep interest in sensory coding – how the brain takes in and “maps” sensory input to give rise to perception and behavior. Our model system is the sense of taste. Taste is a component of flavor, which also involves mouthfeel (touch, temperature) and smell. Taste and flavor critically guide ingestive decisions that impact nutritional status and well being in diverse animals, humans included. We study taste and sensory information processing in the brain using a collection of approaches, including neurophysiology, math, animal behavior, and genetics. Our research is funded by the National Institutes of Health, U.S. Department of Health & Human Services.

Some of the ongoing experiments in the lab are centered on delineating the receptive range of taste-sensitive neurons – what are the sensations conveyed by these cells? At first glance, the answer to this question may seem obvious – taste neurons convey one of the five human taste categories of “sweet”, “salty”, “sour”, “bitter”, or “umami”, which is the taste of MSG. However, recent, and also early, advances in gustatory neurobiology challenge the assumption that taste-sensitive neurons detect and register solely five tastes. For instance, published data from several labs, ours included, have revealed that different stimuli from the “bitter” category can induce very different patterns of neural activity. This raises the possibility that the nervous system can register differences between stimuli classified as “bitter”, which questions the singularity of this taste category. We are continuing to explore this issue.

What is more, cells in the brain responsive to taste chemicals have been classically defined as “gustatory” neurons, albeit many of these cells do not show selective tuning to only taste. Taste-sensitive neurons can also respond to oral somatosensation, which includes touch and temperature stimulation inside the mouth. This feature positions “gustatory” neurons to function as integrators of taste and oral cutaneous sensation, a process of generating flavor. We are studying the details of this integration in brain stem circuits.
 


Ph.D., Binghamton University, State University of New York

M.A., Binghamton University, State University of New York


B.S., University of Oklahoma

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Selected publications:

  • Wilson, D.M., Boughter, J.D. Jr., and Lemon, C.H. (2012) Bitter taste stimuli induce differential neural codes in mouse brain. PLoS ONE, 7(7): e41597. doi:10.1371. PMID: 22844505

  • Brasser, S.M., Silbaugh, B.C., Ketchum, M.J., Olney, J.J., and Lemon, C.H. (2012) Chemosensory responsiveness to ethanol and its individual sensory components in alcohol-preferring, -nonpreferring and genetically heterogeneous rats. Addiction Biology, 17 (2): 423-436. PMID: 22129513

  • Lemon, C.H., Wilson, D.M. and Brasser, S.M. (2011) Differential neural representation of oral ethanol by central taste-sensitive neurons in ethanol-preferring and genetically heterogeneous rats. Journal of Neurophysiology, 106 (6): 3145-3156. PMID: 21918002

  • Lemon, C.H. and Margolskee, R.F. (2009) Contribution of the T1r3 taste receptor to the response properties of central gustatory neurons. Journal of Neurophysiology, 101 (5): 2459-2471. PMID: 19279151

  • Lemon, C.H. and Katz, D.B. (2007) The neural processing of taste. BMC Neuroscience, 8 (Suppl 3): S5, 2007. PMID: 17903281

  • Lemon, C.H. and Smith, D.V. (2006) Influence of response variability on the coding performance of central gustatory neurons. The Journal of Neuroscience, 26 (28): 7433-7443. PMID: 16837591

  • Lemon, C.H., Brasser, S.M. and Smith, D.V. (2004) Alcohol activates a sucrose-responsive gustatory neural pathway. Journal of Neurophysiology, 92 (1): 536-544. PMID: 14985409

  • Di Lorenzo, P.M., Lemon, C.H. and Reich, C.G. (2003) Dynamic coding of taste stimuli in the brain stem: effects of brief pulses of taste stimuli on subsequent taste responses. The Journal of Neuroscience, 23 (26): 8893-8902. PMID: 14523091

  • Lemon, C.H. and Di Lorenzo, P.M. (2002) Effects of electrical stimulation of the chorda tympani nerve on taste responses in the nucleus of the solitary tract. Journal of Neurophysiology, 88 (5): 2477-2489. PMID: 12424287

 

 

 

 

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