Gustatory stimulating technique for glossopharyngeal neurophysiological recordings.
A new stimulating technique for studying the gustatory sensitivity of the glossopharyngeal nerve is presented. Among its other functions the glossopharyngeal nerve relays multisensory information from the posterior tongue region. Study of the gustatory function of this nerve is therefore complicated by concomitant tactile and thermal components. Additionally taste buds innervated by the glossopharyngeal nerve are located in trenches within the foliate and circumvallate papillae which results in slow delivery and removal of tastant solutions. By delivering the stimulus or adapting solution through an infusion pump connected to a double-barrelled pipette placed into the trench of the circumvallate papilla, quick delivery and removal of the stimulus is possible. Moreover the continuous flow of solution, switched from adapting solution to stimulus and back, allows tactile components to completely adapt. Due to both the proximity of the stimulus to the receptors and the continuous flow of the solution this technique produces gustatory responses with large phasic components, as is commonly observed in other gustatory nerves. The temporal characteristics of the gustatory portion of the glossopharyngeal nerve can therefore now be more readily studied.
Herness
M S
MS
Laboratory of Neurobiology and Behavior, Rockefeller University, New York, NY 10021.
D000200:Action Potentials / Q000187:drug effects; D000643:Ammonium Chloride / Q000494:pharmacology; D000818:Animals; D002628:Chemoreceptor Cells / Q000187:drug effects / Q000502:physiology*; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods*; D005930:Glossopharyngeal Nerve / Q000187:drug effects / Q000502:physiology*; D008465:Mechanoreceptors / Q000502:physiology*; D010812:Physical Stimulation; D051381:Rats; D012965:Sodium Chloride / Q000494:pharmacology; D013650:Taste Buds / Q000294:innervation*
D000643:Ammonium Chloride; D012965:Sodium Chloride