Glucose Sensitivity of Mitral Cell Neurons of the Olfactory Bulb

Summary

Principal Investigator: KRISTAL RAYLONE TUCKER
Abstract: The ability to find and ascess the quality of palatable food is dependent on external sensory stimuli, such as olfactory and visual cues. The need to find food is signalled to the brain by changes in feeding-related hormones and metabolites such as insulin, leptin and glucose. Blood and brain levels of glucose and insulin fall and rise acutely with feeding state and are chronically elevated during obesity and diabetes. Fasted animals perform better in olfactory tests. Acute insulin application has been found to suppress the current of a voltage-gated potassium channel (Kv1.3) prominently expressed in mitral cells of the olfactory bulb as well as modulate the spontaneous activity of the mitral cell. Together these results suggest that the mitral cell is able to sense feeding state by feeding-related hormones and metabolites at the level of the olfactory bulb. This proposal will address the following questions: 1. Is mitral cell electrical activity acutely modulated by changes in glucose and are potassium channels, including Kv1.3, involved? 2. How do chronic glucose and insulin modulate mitral cell electrical activity? To answer these questions various concentrations of metabolically active and inactive isoforms of glucose will be acutely applied during whole-cell current- and voltage-clamp olfactory bulb slice mitral cell recordings, and chronically applied for 7 days by intranasal delivery of insulin and glucose followed by similar olfactory bulb slice electrophysiological recordings. PUBLIC HEALTH RELEVANCE: The far reaching relevance of this research is in increasing our understanding of how neuronal activity is changed in response to acute feeding-related glucose changes, as well as, in disease states such as hypoglycemia, diabetes and obesity, when glucose levels are chronically depleted or elevated. With the ever increasing obese population in the United States, it will be important to understand how the chemistry of the obese state affects brain function.
Funding Period: ----------------2009 - ---------------2010-
more information: NIH RePORT

Top Publications

  1. pmc The Olfactory Bulb: A Metabolic Sensor of Brain Insulin and Glucose Concentrations via a Voltage-Gated Potassium Channel
    Kristal Tucker
    Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
    Results Probl Cell Differ 52:147-57. 2010
  2. pmc Diet-induced obesity resistance of Kv1.3-/- mice is olfactory bulb dependent
    K Tucker
    Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
    J Neuroendocrinol 24:1087-95. 2012
  3. pmc Olfaction under metabolic influences
    Brigitte Palouzier-Paulignan
    Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028 CNRS 5292, Université de Lyon1, 50 Ave Tony Garnier, 69366, Lyon, Cedex 07, France
    Chem Senses 37:769-97. 2012
  4. pmc Glucose sensitivity of mouse olfactory bulb neurons is conveyed by a voltage-gated potassium channel
    Kristal Tucker
    Florida State University, 319 Stadium Drive, 3008 King Life Sciences, Tallahassee, FL 32306, USA
    J Physiol 591:2541-61. 2013
  5. pmc Mitral cells of the olfactory bulb perform metabolic sensing and are disrupted by obesity at the level of the Kv1.3 ion channel
    Debra Ann Fadool
    Program in Neuroscience, The Florida State University, Tallahassee, Florida, United States of America
    PLoS ONE 6:e24921. 2011

Detail Information

Publications5

  1. pmc The Olfactory Bulb: A Metabolic Sensor of Brain Insulin and Glucose Concentrations via a Voltage-Gated Potassium Channel
    Kristal Tucker
    Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
    Results Probl Cell Differ 52:147-57. 2010
    ..We have discovered that Kv1.3 contributes an unusual nonconducting role - the detection of metabolic state...
  2. pmc Diet-induced obesity resistance of Kv1.3-/- mice is olfactory bulb dependent
    K Tucker
    Program in Neuroscience, The Florida State University, Tallahassee, FL, USA
    J Neuroendocrinol 24:1087-95. 2012
    ..Thus, these findings add to a growing body of evidence suggesting that the olfactory system can modulate the pathways involved in the regulation of energy balance...
  3. pmc Olfaction under metabolic influences
    Brigitte Palouzier-Paulignan
    Centre de Recherche des Neurosciences de Lyon, Equipe Olfaction du Codage à la Mémoire, INSERM U 1028 CNRS 5292, Université de Lyon1, 50 Ave Tony Garnier, 69366, Lyon, Cedex 07, France
    Chem Senses 37:769-97. 2012
    ....
  4. pmc Glucose sensitivity of mouse olfactory bulb neurons is conveyed by a voltage-gated potassium channel
    Kristal Tucker
    Florida State University, 319 Stadium Drive, 3008 King Life Sciences, Tallahassee, FL 32306, USA
    J Physiol 591:2541-61. 2013
    ..3 expression. Given the rising incidence of metabolic disorders attributed to weight gain, changes in neuronal excitability in brain regions regulating sensory perception of food are of consequence...
  5. pmc Mitral cells of the olfactory bulb perform metabolic sensing and are disrupted by obesity at the level of the Kv1.3 ion channel
    Debra Ann Fadool
    Program in Neuroscience, The Florida State University, Tallahassee, Florida, United States of America
    PLoS ONE 6:e24921. 2011
    ..Our results implicate an inappropriate neural function of olfactory sensors following exposure to chronic levels of the hormone insulin (diabetes) or increased body weight (obesity)...