Multifiber Electrodes for the Direct Detection of Neurotransmitter Release from Taste Buds
Submission Type
Event
Expected Graduation Date
2014
Location
Center for Natural Sciences, Illinois Wesleyan University
Start Date
4-12-2014 2:00 PM
End Date
4-12-2014 3:00 PM
Disciplines
Chemistry
Abstract
Mammalian taste buds are known to contain releasable stores of norepinephrine (NE) and serotonin (5-HT), both of which are electroactive neurotransmitters amenable to detection by amperometry and cyclic voltammetry. However, repeated attempts to detect the release of NE and 5-HT in isolated mouse taste buds (approx. width of 50-70 µm) with single carbon fiber electrodes have been unsuccessful. The taste bud is a tight collection of 50 to 100 taste cells, only about 20 percent of which contain NE and 5-HT, and therefore the probability of positioning a single carbon fiber electrode (5-7 µm in diameter) at a release site is very low. We have found that it is possible to greatly increase the probability of finding release sites using carbon fiber electrodes containing approximately 10 to 40 carbon fibers, each having a diameter of 7 µm. These multifiber electrodes have overall diameters between 30 and 70 µm (including the glass insulating sheath) and therefore cover between 50 and 100% of the exposed surface of the taste bud. It was possible to use amperometry at these electrodes to directly detect calcium-dependent vesicular release of neurotransmitter by depolarization with KCl and by stimulation with sweet, sour, and bitter tastants. Furthermore, we have used this approach to demonstrate that mouse taste buds release neurotransmitters in response to stimulation by linoleic acid. These results demonstrate that multifiber electrodes promise to be important tools for investigating the sense of taste and the mechanism of neurotransmission between taste cells and between the taste buds and the afferent neuron. Additionally, multiple-chamber multifiber electrodes are in development which will allow for simultaneous, independent assessment of distinct areas of the taste bud.
Multifiber Electrodes for the Direct Detection of Neurotransmitter Release from Taste Buds
Center for Natural Sciences, Illinois Wesleyan University
Mammalian taste buds are known to contain releasable stores of norepinephrine (NE) and serotonin (5-HT), both of which are electroactive neurotransmitters amenable to detection by amperometry and cyclic voltammetry. However, repeated attempts to detect the release of NE and 5-HT in isolated mouse taste buds (approx. width of 50-70 µm) with single carbon fiber electrodes have been unsuccessful. The taste bud is a tight collection of 50 to 100 taste cells, only about 20 percent of which contain NE and 5-HT, and therefore the probability of positioning a single carbon fiber electrode (5-7 µm in diameter) at a release site is very low. We have found that it is possible to greatly increase the probability of finding release sites using carbon fiber electrodes containing approximately 10 to 40 carbon fibers, each having a diameter of 7 µm. These multifiber electrodes have overall diameters between 30 and 70 µm (including the glass insulating sheath) and therefore cover between 50 and 100% of the exposed surface of the taste bud. It was possible to use amperometry at these electrodes to directly detect calcium-dependent vesicular release of neurotransmitter by depolarization with KCl and by stimulation with sweet, sour, and bitter tastants. Furthermore, we have used this approach to demonstrate that mouse taste buds release neurotransmitters in response to stimulation by linoleic acid. These results demonstrate that multifiber electrodes promise to be important tools for investigating the sense of taste and the mechanism of neurotransmission between taste cells and between the taste buds and the afferent neuron. Additionally, multiple-chamber multifiber electrodes are in development which will allow for simultaneous, independent assessment of distinct areas of the taste bud.