title: Functional properties of tooth pulp neurons responding to thermal stimulation.
abstract: The response properties of tooth pulp neurons that respond to noxious thermal stimulation of the dental pulp have been not well-studied. The present study was designed to characterize the response properties of tooth pulp neurons to noxious thermal stimulation of the dental pulp. Experiments were conducted on 25 male ferrets, and heat stimulation was applied by a computer-controlled thermode. Only 15% of tooth pulp neurons (n = 39) responded to noxious thermal stimulation of the teeth. Tooth pulp neurons were found in both the superficial and deep nuclear regions of the subnucleus caudalis (Vc) and in the interface between the nucleus caudalis and interpolaris (Vc/Vi). Thirty-seven neurons had cutaneous receptive fields and were classified as either NS (16) or WDR (21) neurons. Repeated heat stimulation of the dental pulp sensitized and increased the number of electrically evoked potentials of tooth pulp neurons. These results provide evidence that both the Vc and Vc/Vi regions contain neurons that respond to noxious thermal stimulation of the dental pulp, and that these cells may contribute to the sensitization process associated with symptomatic pulpitis.
authors.affiliation: Department of Oral Physiology, School of Dentistry, Kyungpook National University, 188-1 Sam Deok 2ga, Chung-gu, Daegu, Korea. dkahn@knu.ac.kr
authors.forename: D K
authors.initials: DK
authors.lastname: Ahn
authors.forename: E A
authors.initials: EA
authors.lastname: Doutova
authors.forename: K
authors.initials: K
authors.lastname: McNaughton
authors.forename: A R
authors.initials: AR
authors.lastname: Light
authors.forename: M
authors.initials: M
authors.lastname: Närhi
authors.forename: W
authors.initials: W
authors.lastname: Maixner
mesh_terms: D000818:Animals; D003080:Cold Temperature; D003481:Cuspid / Q000294:innervation; D003782:Dental Pulp / Q000294:innervation*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology; D005289:Ferrets; D005881:Gingiva / Q000294:innervation; D006358:Hot Temperature; D008046:Lip / Q000294:innervation; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D009061:Mouth Mucosa / Q000294:innervation; D009431:Neural Conduction / Q000502:physiology; D009474:Neurons / Q000145:classification / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D010812:Physical Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology; D012867:Skin / Q000294:innervation; D013823:Thermoreceptors / Q000502:physiology; D013697:Thermosensing / Q000502:physiology*; D014275:Trigeminal Caudal Nucleus / Q000166:cytology / Q000502:physiology