The Olfactory Bulb: A Metabolic Sensor of Brain Insulin and Glucose Concentrations via a Voltage-Gated Potassium Channel.
The voltage-gated potassium channel, Kv1.3, contributes a large proportion of the current in mitral cell neurons of the olfactory bulb where it assists to time the firing patterns of action potentials as spike clusters that are important for odorant detection. Gene-targeted deletion of the Kv1.3 channel, produces a "super-smeller" phenotype, whereby mice are additionally resistant to diet- and genetically-induced obesity. As assessed via an electrophysiological slice preparation of the olfactory bulb, Kv1.3 is modulated via energetically important molecules - such as insulin and glucose - contributing to the body's metabolic response to fat intake. We discuss a biophysical characterization of modulated synaptic communication in the slice following acute glucose and insulin stimulation, chronic elevation of insulin in mice that are in a conscious state, and induction of diet-induced obesity. We have discovered that Kv1.3 contributes an unusual nonconducting role - the detection of metabolic state.
Tucker
Kristal
K
Program in Neuroscience, The Florida State University, Tallahassee, FL, USA.
Cavallin
Melissa Ann
MA
Jean-Baptiste
Patrick
P
Biju
K C
KC
Overton
James Michael
JM
Pedarzani
Paola
P
Fadool
Debra Ann
DA
D000818:Animals; D001921:Brain / Q000378:metabolism*; D001923:Brain Chemistry; D005947:Glucose / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000032:analysis / Q000378:metabolism*; D051664:Kv1.3 Potassium Channel / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D051379:Mice; D009830:Olfactory Bulb / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009994:Osmolar Concentration; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism / Q000502:physiology*; D012677:Sensation / Q000502:physiology; D012903:Smell / Q000235:genetics / Q000502:physiology
D007328:Insulin; D051664:Kv1.3 Potassium Channel; D024642:Potassium Channels, Voltage-Gated; D005947:Glucose