Neurobiology of the Central Gustatory System
My research examines the anatomy, pharmacology and function of the central gustatory (taste) system. Specifically, I am interested in how the brainstem gustatory areas process taste information and produce the appropriate behavioral responses. Currently, this work is funded by the National Institutes of Health (RO1 DC007854).
The main experimental approach is to evaluate the behavioral effects of introducing drugs, that either mimic or antagonist neurotransmitter action, into the brainstem. For example, since we have anatomical evidence that the projection from the tasting area in the medulla (nucleus of the solitary tract) to the pontine taste area (parabrachial nucleus) contains the neurotransmitter glutamate and behavioral evidence that the injection of glutamate into the parabrachial nucleus causes oromotor behaviors, we hypothesize that blocking glutamate function in the parabrachial nucleus will alter behavioral responses to taste solutions put on the tongue.
Experiments to test this hypothesis are performed by implementing laboratory rats with intra-cranial (to inject the drug) and intra-oral (to infuse the taste solution) cannula, allowing the rats about a week to recover from surgery and then analyzing the behavioral responses to tastes with and without the injection of drugs into the parabrachial nucleus. This semester there are 6 students performing these types of experiments in my laboratory and over the past few years there have been a few presentations on this subject at scientific meetings (see references below). Manuscripts are being prepared for submission as well.
If you are interested in this research or would like more information, please contact Dr. Michael S. King by email at [email protected] or by phone at 386-822-8173.
- King, MS, Delaney, K. and Gelperin, A., (1987), Acetylcholine activates cerebral interneurons and feeding motor program in Limax maximus. J. Neurobiology 18:509-530.
- King, MS and Baertschi, A.J., (1989), Physiological concentrations of atrial natriuretic factors with intact N-terminal sequences inhibit corticotropin-releasing factor-stimulated adrenocorticotropin secretion from cultured anterior pituitary cells. Endocrinology:286-292.
- King, MS and Baertschi, A.J., (1990), The role of intracellular messengers in adrenocorticotropin secretion in vitro. Experientia 46:26-40.
- King, MS and Baertschi, A.J., (1991), Central neural pathway mediating splanchnic osmosensation. Brain Research 550:268-278.
- King, MS and Baertschi, A.J., (1992), Ventral pontine catecholaminergic pathway mediates the vasopressin response to splanchnic osmostimulation in conscious rats. Brain Research 580:81-91.
- King, MS, Wang, L. and Bradley, R.M., (1993), Substance P excites neurons in the gustatory zone of the rat nucleus tractus solitarius. Brain Research 619:120-130.
- King, MS and Bradley, R.M., (1994), Relationship between structure and function of neurons in the rat rostral nucleus tractus solitarii. J. Comparative Neurology 344:50-64.
- Bradley, R.M., King, MS, Wang, L. and Shu, X., (1996), Neurotransmitter and neuromodulatory activity in the gustatory zone of the nucleus tractus solitarius. Chemical Senses 21:377-385.
- *Williams, J.B., *Murphy, D.M., *Reynolds, K.E., *Welch, S.J. and King, MS, (1996), Demonstration of a bilateral projection from the rostral nucleus of the solitary tract to themedial parabrachial nucleus in rat. Brain Research 737:231-237.
- *Gill, C.F., *Madden, J.M., *Roberts, B.P., *Evans, L.D. and King, MS, (1999), A subpopulation of neurons in the rat rostral nucleus of the solitary tract that project to the parabrachial nucleus express glutamate-like immunoreactivity. Brain Research 821:251-262.
- King, MS and Bradley, R.M., (2000), Biophysical properties and responses to glutamate receptor agonists of identified subpopulations of rat geniculate ganglion neurons. Brain Research 866: 237-246.
- King, MS, (2003), Distribution of immunoreactive GABA and glutamate receptors in the gustatory portion of the nucleus of the solitary tract in rat. Brain Research Catalog 60:241-254.
- *Galvin, K.E., King, C.T. and King, MS, (2004), Stimulation of specific parabrachial subnuclei elicits ingestive oromotor behaviors in conscious rats. Behavioral Neuroscience 118:163-172.
- Harrison, T.A., Hoover, D.B. and King, MS, (2004), Distinct regional distributions of NK1 and NK3 neurokinin receptor immunoreactivity in rat brainstem gustatory centers. Brain Research Catalog 63:7-17.
- King, MS, *Wildeboer, K.M., *Cunningham, J.C., *Gill, C.F. and *Moore, W.D., (2000), Distribution of glutamate receptor immunoreactivity in the rat rostral nucleus of the solitary tract. 30th Annual meeting of the Society for Neuroscience, New Orleans, Abstract #638.10.
- King, MS, *Graham, J.N., *Koepnick, K.K, *Townsend, J.M. and *Thomas, L.A., (2001), Electrical and chemical stimulation of specific regions of the PBN elicits ingestive oromotor behaviors in conscious rats. Abstract #308, Chemical Senses 26:1105-1106.
- King, MS, *Dykes, R.E. and King, C.T., (2002), Electrical stimulation of the PBN elicits ingestive oromotor behaviors in conscious rats: a topographic analysis. 24th Annual Meeting of the Association for Chemoreception Sciences, Abstract #330.
- King, MS, (2002), Distribution of immunoreactive GABA and glutamate receptors in the rostral nucleus of the solitary tract in rat. 32nd Annual Meeting of the Society for Neuroscience, Orlando, Abstract #356.5.
- King, MS, *Smith, M.T., *Jani, K.P. and King, C.T., (2003), The location of Fos-immunoreactive neurons following electrical stimulation of the gustatory parabrachial nucleus in conscious rats. 33rd Annual Meeting of the Society for Neuroscience, New Orleans, Abstract #594.8.
- King, MS, *Keller, G.S. and *Uflacker, A.B., (2004), Blocking glutamate receptors in the parabrachial nucleus reduces aversive oromotor responses to quinine in conscious rats. 26th Annual Meeting of the Association for Chemoreception Sciences, Abstract #207.
- Maddox, L.A. and King, MS, (2005), CCK injections into the taste area of the parabrachial nucleus alter oromotor behaviors to intra-oral infusions of quinine in conscious rats. Annual Biomedical Research Conference for Minority Students, Atlanta, Abstract.
- King, MS, *Delmond, J.A. and Maddox, L.C., (2006), Injection of cholecystokinin into the waist area of the parabrachial nucleus increases taste reactivity responses to intra-oral infusion of quinine in rats. Abstract #397, Chemical Senses:490.
- King, MS, (2006), Anatomy of the Rostral Nucleus of the Solitary Tract. In, Bradley, R.M. (Ed.), The Role of the Nucleus of the Solitary Tract in Gustatory Processing, Taylor and Francis Group, Boca Raton, FL., pp. 17-38.
- Bradley, R.M. and King, MS, (2006), Neurotransmitters and Receptors Expressed by rNST Neurons. In, Bradley, R.M. (Ed.), The Role of the Nucleus of the Solitary Tract in Gustatory, Taylor and Francis Group, Boca Raton, FL., pp. 38-66.