CHRISTIAN H. LEMON, Ph.D.

Assistant Professor

Department of Anatomy and Neurobiology

The University of Tennessee College of Medicine

Address

The University of Tennessee Health Science Center

855 Monroe Avenue, Suite 515

Memphis, TN 38163

Tel: (901) 448-1139;

Education

Ph.D. Institution: State University of New York at Binghamton, Department of Psychology

Postdoctoral: National Institutes of Health Fellow: University of Maryland School of Medicine, Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Department of Anatomy and Neurobiology

Research Interests

I am interested in sensory systems and how the neural circuits that compose these systems are organized to give rise to perception and behavior.  My research has focused on the neural processing of taste, specifically on how information about the identity of taste stimuli is represented by the activities of central gustatory neurons.  Understanding this issue bears not only on delineating principles of gustatory coding, but on the mechanisms by which taste factors guide our selection of foods and impact nutritional status.  My research on gustatory processing utilizes a multifaceted approach that is rooted in systems neurophysiology.  

Recent work has applied techniques drawn from signal detection theory to the analysis of the spiking activities of central taste neurons to deduce a model of gustatory coding that is based on the information-handling limits of these cells (PubMed).  The outcome here supports the notion that taste stimuli are represented by a distributed neural code that involves the activities of cells with different tuning properties.  This model is being further explored for taste stimuli tested under varied conditions.

Other studies in the lab are using neurophysiological recordings and genetically-targeted mice to investigate taste processing.  An ongoing project involves sampling central gustatory neurons from strains of mice that carry different functional alleles of genes for particular taste receptors.  Categories of neurons that differ in their sensitivities to taste stimuli between strains likely receive input from the receptor products of these genes.  By identifying such neurons, this project aims to map out patterns of “wiring” between types of taste receptors in the mouth and gustatory neurons in the brain.  This work is funded by a grant to CHL from the National Institutes of Health.

Finally, I am involved in a collaborative line of research with Dr. Susan Brasser (San Diego State University) that aims to understand the oral sensory processing of ethanol, the alcohol in all alcoholic beverages consumed by humans.  Recent findings from our laboratory and others have indicated that the nervous system registers the taste of ethanol as similar to a sweet stimulus (e.g., PubMed).  We are exploring how ethanol’s taste and oral trigeminal properties influence alcohol preference.

Recent Publications

• Lemon CH, Katz DB. The neural processing of taste. BMC Neurosci. 2007 Sep 18;8 Suppl 3:S5. Review. PMID: 17903281
• Lemon CH, Smith DV. Influence of response variability on the coding performance of central gustatory neurons. J Neurosci. 2006 Jul 12;26(28):7433-43. PMID: 16837591
• Lemon CH, Smith DV. Neural representation of bitter taste in the nucleus of the solitary tract. J Neurophysiol. 2005 Dec;94(6):3719-29. Epub 2005 Aug 17. PMID: 16107527
• Lemon CH, Brasser SM, Smith DV. Alcohol activates a sucrose-responsive gustatory neural pathway. J Neurophysiol. 2004 Jul;92(1):536-44. Epub 2004 Feb 25. PMID: 14985409
• Di Lorenzo PM, Lemon CH, Reich CG. Dynamic coding of taste stimuli in the brainstem: effects of brief pulses of taste stimuli on subsequent taste responses. J Neurosci. 2003 Oct 1;23(26):8893-902. PMID: 14523091
• Lemon CH, Imoto T, Smith DV. Differential gurmarin suppression of sweet taste responses in rat solitary nucleus neurons. J Neurophysiol. 2003 Aug;90(2):911-23. Epub 2003 Apr 17. PMID: 12702710

view complete list of references (pubmed link)