title: Separate functions for responses to oral temperature in thermo-gustatory and trigeminal neurons.
abstract: Oral temperature is a component and modifier of taste perception. Both trigeminal (V) and taste-sensitive cells, including those in the nucleus of the solitary tract (NTS), can respond to oral temperature. However, functional associations in thermal sensitivity between V and gustatory neurons are poorly understood. To study this we recorded electrophysiological responses to oral stimulation with cool (9, 15, 25, 32, and 34 °C) and warm (40 and 45 °C) temperatures from medullary V (n = 45) and taste-sensitive NTS (n = 27) neurons in anesthetized mice. Results showed temperatures below 34 °C activated the majority of V neurons but only a minority of NTS units. V neurons displayed larger responses to cooling and responded to temperatures that poorly stimulated NTS cells. Multivariate analyses revealed different temperatures induced larger differences in responses across V compared with NTS neurons, indicating V pathways possess greater capacity to signal temperature. Conversely, responses to temperature in NTS units associated with gustatory tuning. Further analyses identified two types of cooling-sensitive V neurons oriented toward innocuous or noxious cooling. Multivariate analyses indicated the combined response of these cells afforded distinction among a broad range of cool temperatures, suggesting multiple types of V neurons work together to represent oral cooling.
authors.affiliation: Department of Biology, The University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA lemon@ou.edu.
authors.forename: Christian H
authors.initials: CH
authors.lastname: Lemon
authors.affiliation: Department of Biology, The University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Biology, The University of Oklahoma, 730 Van Vleet Oval, Norman, OK 73019, USA.
authors.forename: Jinrong
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D004558:Electric Stimulation; D005071:Evoked Potentials; D005260:Female; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D015999:Multivariate Analysis; D009474:Neurons / Q000502:physiology*; D017552:Solitary Nucleus / Q000502:physiology; D055697:Taste Perception / Q000502:physiology*; D013696:Temperature
keywords: multisensory; neural coding; nucleus of the solitary tract; taste; temperature; trigeminal