Taste Activity in the Adult Glossopharyngeal Nerve Following Neonatal Chorda Tympani Nerve Injury in Rats
Advisor Information
Suzanne Sollars
Location
Milo Bail Student Center Ballroom
Presentation Type
Poster
Start Date
8-3-2013 9:00 AM
End Date
8-3-2013 12:00 PM
Abstract
The chorda tympani nerve (CT) transmits taste information from the anterior tongue to the brain. Adult rats receiving chorda tympani transection (CTX), or cutting of the CT, show remarkable structural, functional, and behavioral recovery. However, when the same surgery is performed on neonatal rats (at 5 to 10 days of age), these animals have long-term structural deficits. Interestingly, rats receiving CTX as neonates but not as adults show an abnormal preference for a sour/bitter salt, ammonium chloride (NH4Cl), as adults. One possible reason for this nerve-induced change in behavior could be that the remaining taste nerves have functional changes following neonatal CTX. To examine this hypothesis, rats received either CTX or a control surgery at 5 days of age. After reaching adulthood, electrical activity from the rats’ glossopharyngeal nerve (which carries taste information from the rear 1/3rd of the tongue to the brain) was recorded during application of various concentrations of NH4Cl, NaCl, and sucrose. There were no differences in nerve response to NH4Cl or NaCl. However, activity following sucrose administration was significantly higher in the CTX group. While the mechanisms underlying this injury-induced change in responding are not clear, these results could help explain the observed correlation between early chorda tympani damage and a higher consumption of sugary foods in humans. Glossopharyngeal recordings will soon be performed on rats receiving CTX at 10 days of age to determine how age of injury affects nerve activity.
Taste Activity in the Adult Glossopharyngeal Nerve Following Neonatal Chorda Tympani Nerve Injury in Rats
Milo Bail Student Center Ballroom
The chorda tympani nerve (CT) transmits taste information from the anterior tongue to the brain. Adult rats receiving chorda tympani transection (CTX), or cutting of the CT, show remarkable structural, functional, and behavioral recovery. However, when the same surgery is performed on neonatal rats (at 5 to 10 days of age), these animals have long-term structural deficits. Interestingly, rats receiving CTX as neonates but not as adults show an abnormal preference for a sour/bitter salt, ammonium chloride (NH4Cl), as adults. One possible reason for this nerve-induced change in behavior could be that the remaining taste nerves have functional changes following neonatal CTX. To examine this hypothesis, rats received either CTX or a control surgery at 5 days of age. After reaching adulthood, electrical activity from the rats’ glossopharyngeal nerve (which carries taste information from the rear 1/3rd of the tongue to the brain) was recorded during application of various concentrations of NH4Cl, NaCl, and sucrose. There were no differences in nerve response to NH4Cl or NaCl. However, activity following sucrose administration was significantly higher in the CTX group. While the mechanisms underlying this injury-induced change in responding are not clear, these results could help explain the observed correlation between early chorda tympani damage and a higher consumption of sugary foods in humans. Glossopharyngeal recordings will soon be performed on rats receiving CTX at 10 days of age to determine how age of injury affects nerve activity.