Biomaterial Database

Response properties of nociceptive and non-nociceptive neurons in the rat's trigeminal subnucleus caudalis (medullary dorsal horn) related to cutaneous and deep craniofacial afferent stimulation and modulation by diffuse noxious inhibitory controls. 1990

James W Hu

Faculty of Dentistry, University of Toronto, Toronto, Ont. M5G 1G6, Canada.

An electrophysiological study was carried out in anesthetized rats to characterize the properties of single neurons in trigeminal (V) subnucleus caudalis. Each neuron was functionally classified in terms of its cutaneous mechanoreceptive field properties as low-threshold mechanoreceptive (LTM), wide dynamic range (WDR) or nociceptive-specific (NS), and its responsiveness was also tested to electrical stimulation of hypoglossal (XII) nerve muscle afferents. Some neurons were also tested with noxious stimulation of the tail or forepaw for the presence of diffuse noxious inhibitory controls (DNIC) of evoked responses. A mechanoreceptive field localized to the ipsilateral orofacial region was a feature of all the neurons which were located in laminae I-VI; the LTM neurons predominated in laminae III/IV whereas the nociceptive (WDR, NS) were located in the superficial and especially deeper laminae of caudalis. The majority of the WDR and NS neurons were also activated by noxious heating as well as by noxious mechanical and electrical stimulation of their orofacial mechanoreceptive field, and in contrast to our previous studies in cats, most of these caudalis nociceptive neurons received C fiber as well as A fiber cutaneous afferent inputs. In contrast to the LTM neurons, but consistent with our previous data in cats, many of the nociceptive neurons also received convergent excitatory inputs from XII muscle afferents, and the stimulus-response functions of the WDR neurons indicated that they were capable of coding the intensity of A and C fiber craniofacial muscle afferent inputs as well as those from cutaneous afferents. The study has also documented for the first time that muscle afferent-evoked responses as well as those evoked by cutaneous afferent inputs to nociceptive neurons are subject to DNIC. These findings indicate that subnucleus caudalis plays an important role in the transmission of superficial and deep nociceptive information from the craniofacial region of the rat, and also reveal that responses of the nociceptive neurons evoked by deep as well as superficial afferent inputs can be powerfully modulated by other nociceptive influences originating from widespread parts of the body.

UI	MeSH Term	Description	Entries
D007002	Hypoglossal Nerve	The 12th cranial nerve. The hypoglossal nerve originates in the hypoglossal nucleus of the medulla and supplies motor innervation to all of the muscles of the tongue except the palatoglossus (which is supplied by the vagus). This nerve also contains proprioceptive afferents from the tongue muscles.	Cranial Nerve XII,Twelfth Cranial Nerve,Nerve XII,Nervus Hypoglossus,Cranial Nerve XIIs,Cranial Nerve, Twelfth,Cranial Nerves, Twelfth,Hypoglossal Nerves,Hypoglossus, Nervus,Nerve XII, Cranial,Nerve XIIs,Nerve XIIs, Cranial,Nerve, Hypoglossal,Nerve, Twelfth Cranial,Nerves, Hypoglossal,Nerves, Twelfth Cranial,Twelfth Cranial Nerves,XII, Nerve,XIIs, Nerve
D008297	Male		Males
D008465	Mechanoreceptors	Cells specialized to transduce mechanical stimuli and relay that information centrally in the nervous system. Mechanoreceptor cells include the INNER EAR hair cells, which mediate hearing and balance, and the various somatosensory receptors, often with non-neural accessory structures.	Golgi Tendon Organ,Golgi Tendon Organs,Krause's End Bulb,Krause's End Bulbs,Mechanoreceptor,Mechanoreceptor Cell,Meissner's Corpuscle,Neurotendinous Spindle,Neurotendinous Spindles,Receptors, Stretch,Ruffini's Corpuscle,Ruffini's Corpuscles,Stretch Receptor,Stretch Receptors,Mechanoreceptor Cells,Bulb, Krause's End,Bulbs, Krause's End,Cell, Mechanoreceptor,Cells, Mechanoreceptor,Corpuscle, Meissner's,Corpuscle, Ruffini's,Corpuscles, Ruffini's,End Bulb, Krause's,End Bulbs, Krause's,Krause End Bulb,Krause End Bulbs,Krauses End Bulb,Krauses End Bulbs,Meissner Corpuscle,Meissners Corpuscle,Organ, Golgi Tendon,Organs, Golgi Tendon,Receptor, Stretch,Ruffini Corpuscle,Ruffini Corpuscles,Ruffinis Corpuscle,Ruffinis Corpuscles,Spindle, Neurotendinous,Spindles, Neurotendinous,Tendon Organ, Golgi,Tendon Organs, Golgi
D009433	Neural Inhibition	The function of opposing or restraining the excitation of neurons or their target excitable cells.	Inhibition, Neural
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D009619	Nociceptors	Peripheral AFFERENT NEURONS which are sensitive to injuries or pain, usually caused by extreme thermal exposures, mechanical forces, or other noxious stimuli. Their cell bodies reside in the DORSAL ROOT GANGLIA. Their peripheral terminals (NERVE ENDINGS) innervate target tissues and transduce noxious stimuli via axons to the CENTRAL NERVOUS SYSTEM.	Pain Receptors,Receptors, Pain,Nociceptive Neurons,Neuron, Nociceptive,Neurons, Nociceptive,Nociceptive Neuron,Nociceptor,Pain Receptor
D010146	Pain	An unpleasant sensation induced by noxious stimuli which are detected by NERVE ENDINGS of NOCICEPTIVE NEURONS.	Suffering, Physical,Ache,Pain, Burning,Pain, Crushing,Pain, Migratory,Pain, Radiating,Pain, Splitting,Aches,Burning Pain,Burning Pains,Crushing Pain,Crushing Pains,Migratory Pain,Migratory Pains,Pains, Burning,Pains, Crushing,Pains, Migratory,Pains, Radiating,Pains, Splitting,Physical Suffering,Physical Sufferings,Radiating Pain,Radiating Pains,Splitting Pain,Splitting Pains,Sufferings, Physical
D010812	Physical Stimulation	Act of eliciting a response from a person or organism through physical contact.	Stimulation, Physical,Physical Stimulations,Stimulations, Physical
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.