Response patterns to noxious and non-noxious stimuli in rostral trigeminal relay nuclei

Khayyat, G. F.; Yu, Yongbei; King, Rylee

doi:10.1016/0304-3959(76)90124-x

Cited by 8 publications

(5 citation statements)

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“…The response properties of the two populations of PM neurons are similar in the following respects (Beaudreau and Jerge, 1968;Linden, 1978): The great majority of PM neurons are sensitive to only one tooth (in particular, the canine tooth); they are slowly adaptive and directionally selective to mechanical stimulation of the tooth; and they respond to a stimulation force of less than 0.03 N. The central branches of the trigeminal ganglion neurons project ipsilaterally to the secondary Vms and Vst neurons (Darian-Smith, 1973; Linden, 1990). Support for our findings is provided by previous reports that most PM units are located in the rostral part of Vst (Eisenman et al, 1963;Kawamura and Nishiyama, 1966;Yu and King, 1974;Khayyat et al, 1975;Woda et al, 1983). Support for our findings is provided by previous reports that most PM units are located in the rostral part of Vst (Eisenman et al, 1963;Kawamura and Nishiyama, 1966;Yu and King, 1974;Khayyat et al, 1975;Woda et al, 1983).…”

Section: Discussionsupporting

confidence: 85%

Response Properties of Periodontal Mechanosensitive Neurons in the Trigeminal Spinal Tract Nucleus of the Cat

Tabata

Karita

1991

Somatosensory & Motor Research

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Periodontal mechanosensitive (PM) units were recorded from the trigeminal spinal tract nucleus (Vst) of the cat. The Vst is divided into three subnuclei: oralis (Vo), interpolaris (Vi), and caudalis (Vc). The receptive fields of PM units in Vo and Vi were arranged in a dorsoventral sequence in the mandibular to maxillary divisions, and those in Vc were arranged in a mediolateral sequence. The majority of Vo units were single-tooth ones, whereas more than half the Vi units and all the Vc ones were multitooth units. The PM units in each subnucleus were predominantly responsive to canine tooth stimulation. Most of the PM units in Vo and Vi gave sustained responses to pressure applied to the tooth, were directionally selective, and were most actively excited by canine tooth stimulation in the caudomedial or rostrolateral direction. Vc units, however, were transient. The threshold intensity for firings by canine tooth stimulation was less than 0.05 N. These findings indicate that only the response properties of PM units in the rostral part of Vst resemble those of the trigeminal main sensory nucleus neurons and primary afferent nerves.

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Section: Discussionsupporting

confidence: 85%

Response Properties of Periodontal Mechanosensitive Neurons in the Trigeminal Spinal Tract Nucleus of the Cat

Tabata

Karita

1991

Somatosensory & Motor Research

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“…These data, however, contrast with a recent report in the rat which indicates that approximately 20% of LT neurons in pars caudalis are slowly adapting (Hu, 1990). Although the majority of LT mechanoreceptive neurons in other subnuclei of the trigeminal complex are also rapidly adapting, slowly adapting neurons are not uncommon here (Rowe and Sessle, 1972;Darian-Smith, 1973;Mosso and Kruger, 1973;Khayyat et al, 1975;Kirkpatrick and Kruger, 1975). Most commonly, LT neurons in pars caudalis required high-velocity stimuli and most responded with equal numbers of impulses when the skin was indented ("On") and released ("Off').…”

Section: Low-threshold Neuronscontrasting

confidence: 87%

Response properties of nociceptive and low‐threshold neurons in rat trigeminal pars caudalis

McHaffie

Larson

Stein

1994

J of Comparative Neurology

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There is little doubt that trigeminal nociceptive neurons play a critical role in signaling the presence of harmful, or potentially harmful, orofacial stimuli. Unfortunately, there is only a limited understanding of how these neurons code such stimuli and whether this code is maintained in those structures responsible for generating overt reactions. The present series of experiments were designed to quantitatively document the response properties of nociceptive neurons in the rat trigeminal pars caudalis using the same electrical and innocuous and/or noxious mechanical and thermal stimuli employed in the characterization of nociceptive neurons with orofacial receptive fields in the rat superior colliculus. Neurons were classified as either low-threshold mechanoreceptive, wide-dynamic-range, or nociceptive-specific (type I, II) depending on their responsiveness to these stimuli. Nociceptive pars caudalis neurons (92/135, 68%) had receptive field organizations and input fibers (as indicated by latencies to electrical stimuli) quite different from those of low-threshold neurons (43/135, 32%). Nociceptive stimulus-response relationships for the population of wide-dynamic-range and nociceptive-specific type I neurons to contact heat stimuli were positively accelerating power functions with exponents of 3.9 and 4.4, respectively. This contrasted sharply with the low-threshold component of wide-dynamic-range neurons which was a negatively accelerating power function with an exponent of 0.7. All categories of nociceptive neurons also responded vigorously to cold stimuli. The thresholds of both hot and cold stimuli were often below psychophysical estimates of thermal pain, suggesting that "nociceptive" neurons process far more information than that required to signal potentially harmful stimuli. The fundamental similarities in nociceptive properties in pars caudalis and other structures of the central nervous system suggest that there is little transformation of the information encoded at successive levels of the neuraxis. This is consistent with the idea that the functional role of nociceptive neurons is reflected more in which circuits they are integrated and less in differences in their physiological properties.

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“…When the MRA investigations were performed with the 0.5-T machine, the positive ratio in the typical TN group was 60% (12); the corresponding value with the 1-T machine was 88%. This latter positive ratio approaches that for the surgically positive cases of Jannetta (5), and some cause other than NC (probably of central origin (24–26)) in the background of typical TN can be suspected only in 12%. At this point, the question arises of whether it is worth performing MRA in patients with typical TN when the expected negative ratio is only 12%.…”

Section: Discussionmentioning

confidence: 58%

Comparison of Clinical Symptoms and Magnetic Resonance Angiographic (MRA) Results in Patients with Trigeminal Neuralgia and Persistent Idiopathic Facial Pain. Medium-Term Outcome after Microvascular Decompression of Cases with Positive MRA Findings

Kuncz

Vörös²,

Barzó

et al. 2006

Cephalalgia

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Neurovascular compression (NC) seems to have been confirmed as the major cause of classical trigeminal neuralgia (TN). In spite of the large number of surgically positive cases, however, there are still cases where no vascular compression of the trigeminal nerve can be found. To evaluate whether NC could be demonstrated preoperatively, high-resolution magnetic resonance angiography (MRA) was performed in 287 consecutive patients with TN and persistent idiopathic facial pain (PIFP) on a 0.5-T and a 1-T MR unit. Depending on the clinical symptoms, the TN cases were divided into typical TN and trigeminal neuralgia with non-neuralgic interparoxysmal pain (TNWIP) groups. Microvascular decompression (MVD) was performed in 103 of the MRA-positive cases. The patients were followed up postoperatively for from 1 to 10 years. The clinical symptoms were compared with the imaging results. The value of MRA was assessed on the basis of the clinical symptoms and surgical findings. The outcome of MVD was graded as excellent, good or poor. The clinical symptoms were compared with the type of vascular compression and the outcome of MVD. The MRA image was positive in 161 (56%) of the 287 cases. There were significant differences between the clinical groups: 66.5% of the typical TN group, 47.5% of the TNWIP group and 3.4% of the PIFP group were positive. The quality of the MR unit significantly determined the ratio of positive/negative MRA results. The surgical findings corresponded with the MRA images. Six patients from the MRA-negative group were operated on for selective rhizotomy and no NC was found. Venous compression of the trigeminal nerve was observed in a significantly higher proportion in the background of TNWIP than in that of typical TN on MRA imaging (24.1% and 0.8%, respectively) and also during MVD (31.2% and 1.2%, respectively). Four years following the MVD, 69% of the patients gave an excellent, 23% a good and 8% a poor result. The rate of some kind of recurrence of pain was 20% in the typical TN and 44% in TNWIP group. The rate of recurrence was 57% when pure venous compression was present. The only patient who was operated on from the PIFP group did not react to the MVD. The clinical symptoms and preoperative MRA performed by at least a 1-T MR unit furnish considerable information, which can play a role in the planning of the treatment of TN.

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Response patterns to noxious and non-noxious stimuli in rostral trigeminal relay nuclei

Cited by 8 publications

References 0 publications

Response Properties of Periodontal Mechanosensitive Neurons in the Trigeminal Spinal Tract Nucleus of the Cat

Response Properties of Periodontal Mechanosensitive Neurons in the Trigeminal Spinal Tract Nucleus of the Cat

Response properties of nociceptive and low‐threshold neurons in rat trigeminal pars caudalis

Comparison of Clinical Symptoms and Magnetic Resonance Angiographic (MRA) Results in Patients with Trigeminal Neuralgia and Persistent Idiopathic Facial Pain. Medium-Term Outcome after Microvascular Decompression of Cases with Positive MRA Findings

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