Research Interests:

During the last two decades much has been learned about the functioning of taste cells through the identification of taste receptors (eg, T1Rs, T2Rs), functional markers (eg, alpha-gustducin, IP3R3, PLCb2), and synaptic proteins (eg, SNAP-25, syntaxin, synaptobrevin, synaptotagmin). Our laboratory has shown that classical synapses and synaptic proteins are associated with Type III cells. Although both small, clear vesicles and large, dense-cored vesicles are present at Type III synapses, the nature of their neurotransmitters remains a mystery. The situation with Type II cells is even more inscrutable. No classical synapses have been found associated with Type II cells, yet it is generally accepted that Type II cells transduce bitter, sweet and umami stimuli. In addition, recent studies indicate that Type II cells release ATP as a neurotransmitter. We have previously described putative functional contacts for Type II cells, including large, atypical mitochondria which are present at close appositions between taste cells and intragemmal nerve processes.

We propose to examine communication in taste buds by using immunofluorescence and immunoelectron microscopy with colloidal gold labeling or silver-intensified nanogold immunoelectron microscopy to elucidate the nature of functional contacts in taste buds of the mouse.

The goals of my laboratory's research are to answer the following questions:

• Aim 1. What is the nature of the contacts between Type II cells and nerve processes?
• Aim 2. Do Type II cells form specialized contacts with other taste cells?
• Aim 3. What is the nature of the contacts formed by Type III cells with Type II cells and nerve processes?

The results obtained from these studies will help to elucidate the basic mechanisms underlying taste, one of the most complex of the senses. These results will provide an important basis for understanding and treating diseases of the gustatory system. Such an understanding of gustation in health and disease will facilitate future studies of other sensory systems and the nervous system in general.

Link to Kinnamon Publication List

Recent Publications:

• Kataoka S, R Yang, Y Ishimaru, H Matsunami, H Sevigny, J Kinnamon, and TE Finger (2008) The candidate sour taste receptor, PKD2L1, is expressed by Type III taste cells in the mouse. Chemical Senses 33:243-254. (DOI: 10.1093/chemse/bjm083)
• Kinnamon JC and R Yang (2008) Ultrastructure of Taste Buds, in: The Senses: A Comprehensive Reference. G. Beauchamp (ed.), New York: Elsevier.
• Yang R, H Ma, S Thomas and JC Kinnamon (2007) Immunocytochemical analysis of syntaxin-1 in rat circumvallate taste buds. J Comp Neurology 502:883-893. [An image from this manuscript was selected for the cover of the April 23, 2007 issus (Vol. 502, No. 6) of the Journal of Comparative Neurology.] (DOI: 10.1002/cne.21317)
• Ma H, R Yang, S Thomas and JC Kinnamon (2007) Qualitative and quantitative differences between taste buds of the rat and mouse. BMC Neurosciences 8:5 (DOI: 10.1186/1471-2202-8-5)
• Kinnamon JC, M Dunlap and R Yang (2005) Synaptic Connections in developing and adult rat taste buds. Chemical Senses 30:60-61. (DOI: 10.1093/chemse/bjh113)
• Clapp TR, R Yang, CL Stoick, SC Kinnamon, and JC Kinnamon (2004) Morphological characterization of taste cells that express components of the phospholipase C signaling pathway. J Comp Neurology 468:311-321. (DOI: 10.1002/cne.10963)