The Experts below are selected from a list of 222 Experts worldwide ranked by ideXlab platform
Radhouane Dallel - One of the best experts on this subject based on the ideXlab platform.
-
Bilateral Descending Hypothalamic Projections to the Spinal Trigeminal Nucleus Caudalis in Rats
PloS one, 2013Co-Authors: Khaled Abdallah, Radhouane Dallel, Alain Artola, Lénaïc Monconduit, Philippe LuccariniAbstract:Several lines of evidence suggest that the hypothalamus is involved in Trigeminal pain processing. However, the organization of descending hypothalamic projections to the Spinal Trigeminal Nucleus caudalis (Sp5C) remains poorly understood. Microinjections of the retrograde tracer, fluorogold (FG), into the Sp5C, in rats, reveal that five hypothalamic nuclei project to the Sp5C: the paraventricular Nucleus, the lateral hypothalamic area, the perifornical hypothalamic area, the A11 Nucleus and the retrochiasmatic area. Descending hypothalamic projections to the Sp5C are bilateral, except those from the paraventricular Nucleus which exhibit a clear ipsilateral predominance. Moreover, the density of retrogradely FG-labeled neurons in the hypothalamus varies according to the dorso-ventral localization of the Sp5C injection site. There are much more labeled neurons after injections into the ventrolateral part of the Sp5C (where ophthalmic afferents project) than after injections into its dorsomedial or intermediate parts (where mandibular and maxillary afferents, respectively, project). These results demonstrate that the organization of descending hypothalamic projections to the Spinal dorsal horn and Sp5C are different. Whereas the former are ipsilateral, the latter are bilateral. Moreover, hypothalamic projections to the Sp5C display somatotopy, suggesting that these projections are preferentially involved in the processing of meningeal and cutaneous inputs from the ophthalmic branch of the Trigeminal nerve in rats. Therefore, our results suggest that the control of Trigeminal and Spinal dorsal horn processing of nociceptive information by hypothalamic neurons is different and raise the question of the role of bilateral, rather than unilateral, hypothalamic control.
-
both oral and caudal parts of the Spinal Trigeminal Nucleus project to the somatosensory thalamus in the rat
European Journal of Neuroscience, 2005Co-Authors: Nathalie Guy, Radhouane Dallel, Maryse Chalus, Daniel L VoisinAbstract:Recent evidence has been accumulated that not only Spinal Trigeminal Nucleus caudalis (Sp5C) neurons but also Spinal Trigeminal Nucleus oralis (Sp5O) neurons respond to noxious stimuli. It is unknown, however, whether Sp5O neurons project to supraTrigeminal structures implicated in the sensory processing of orofacial nociceptive information. This study used retrograde tracing with Fluorogold in rats to investigate and compare the projections from the Sp5O and Sp5C to two major thalamic nuclei that relay ascending somatosensory information to the primary somatic sensory cortex: the ventroposteromedial thalamic Nucleus (VPM) and the posterior thalamic nuclear group (Po). Results not only confirmed the existence of contralateral projections from the Sp5C to the VPM and Po, with retrogradely labelled neurons displaying a specific distribution in laminae I, III and V, they also showed consistent and similar numbers of retrogradely labelled cell bodies in the contralateral Sp5O. In addition, a topographic distribution of VPM projections from Sp5C and Sp5O was found: neurons in the dorsomedial parts of Sp5O and Sp5C projected to the medial VPM, neurons in the ventrolateral Sp5O and Sp5C projected to the lateral VPM, and neurons in intermediate parts of Sp5O and Sp5C projected to the intermediate VPM. All together, these data suggest that not only the Sp5C, but also the Sp5O relay somatosensory orofacial information from the brainstem to the thalamus. Furthermore, trigemino-VPM pathways conserve the somatotopic distribution of primary afferents found in each subNucleus. These results thus improve our understanding of Trigeminal somatosensory processing and help to direct future electrophysiological investigations.
-
Organization of parabrachial projections from the Spinal Trigeminal Nucleus oralis: an anterograde tracing study in the rat
The Journal of comparative neurology, 2004Co-Authors: Radhouane Dallel, Olivier Ricard, Patrick RaboissonAbstract:In recent years, we have accumulated data showing that the Spinal Trigeminal Nucleus oralis (Sp5O) contributes to the processing of somatosensory inputs from the orofacial region. Although the parabrachial area (PB) represents the main brainstem relay for autonomic, nociceptive, and gustatory afferents, few data are available regarding the topographical distribution of the efferent projections from the Sp5O to the PB. We have addressed this question with the rat, by using the anterograde tracer Phaseolus vulgaris leucoagglutinin. A dense trigeminoparabrachial pathway from the Sp5O toward, predominantly, the ipsilateral PB was revealed. Projections come mainly from the dorsal part of the Sp5O that was found to innervate densely the medial, external medial, and ventral lateral subnuclei. In contrast, the ventral part of the Sp5O projected almost exclusively to an as yet not formally described region, located dorsally and laterally to the lateral tip of the brachium conjunctivum, close to the Kolliker-Fuse Nucleus. These results suggest that distinct regions within the Sp5O may be involved in the processing of gustatory and nociceptive information.
-
Organization of diencephalic projections from the Spinal Trigeminal Nucleus oralis: An anterograde tracing study in the rat
Neuroscience, 2004Co-Authors: Ingrid De Chazeron, Patrick Raboisson, Radhouane DallelAbstract:The organization of the efferent projections from the Spinal Trigeminal Nucleus oralis (Sp5O) to the dienceph-alon was studied in the rat using the anterograde tracer Phaseolus vulgaris leucoagglutinin. The present study confirms the existence of trigemino-thalamic pathways originating from the Sp5O and details their distribution. The main diencephalic targets of the Sp5O are the ventral posterome-dial thalamic Nucleus (VPM), the posterior thalamic nuclei (Po) and the ventral part of the zona incerta (ZIv), contralat-erally, and the parvicellular part of the ventral posterior tha-lamic Nucleus (VPpc), bilaterally. The distribution of these projections varies according to the dorso-ventral location of the injection sites: the dorsal part of the Sp5O projects to the medial part of the VPM and the Po, and to the caudal part of the ZIv, as well as to the VPpc. The ventral part of the Sp5O projects to the lateral part of the VPM and the Po and to the rostral part of the ZIv. These results suggest that the tri-gemino-diencephalic pathways originating from the Sp5O are involved in the processing of gustatory and somatosensory information.
-
ascending connections from the caudal part to the oral part of the Spinal Trigeminal Nucleus in the rat
Neuroscience, 2002Co-Authors: Daniel L Voisin, Radhouane Dallel, Maryse Chalus, S Domejeanorliaguet, Alain WodaAbstract:The brainstem Trigeminal somatosensory complex, while sharing many common aspects with the Spinal somatosensory system, displays features specific to orofacial information processing. One of those is the redundant representation of peripheral structures within the various subnuclei of the complex. A functional redundancy also exists since a single sensory modality, e.g. nociception, may be processed within different subnuclei. In the present study, we addressed the question whether anatomical connections from the caudal part to the oral part of the Spinal Trigeminal Nucleus may support topographical and functional redundancy within the rat Trigeminal somatosensory complex. The retrograde tracer tetramethylrhodamine-dextran was injected iontophoretically into the oral subNucleus of anaesthetised rats. Cell bodies labelled retrogradely from the oral subNucleus were observed in laminae III-IV and V of the ipsilateral caudal subNucleus consistently, and to a lesser degree in lamina I. Such a distribution of retrogradely labelled cells suggested that specific subsets of neurones may relay nociceptive information, and others non-nociceptive information. Furthermore, intraTrigeminal connections conserved the somatotopic distribution of primary afferents in the two subnuclei. First, injections of tracer in the dorsomedial and ventrolateral parts of the oral subNucleus resulted in retrograde labelling of the dorsal and ventral parts of the caudal subNucleus respectively. Second, animals that received tracer into the ventrolateral oral subNucleus displayed more caudal labelling than animals that were injected into the dorsomedial oral subNucleus. These findings show the existence of anatomical connections from the caudal part to the oral part of the Spinal Trigeminal Nucleus in the rat. The connections conserve the somatotopic distribution of primary afferents in the two subnuclei. They provide an anatomical substrate for the indirect activation of Trigeminal oral subNucleus neurones by somatosensory stimuli through the caudal subNucleus.
David A Bereiter - One of the best experts on this subject based on the ideXlab platform.
-
differential effects of morphine on corneal responsive neurons in rostral versus caudal regions of Spinal Trigeminal Nucleus in the rat
Journal of Neurophysiology, 1998Co-Authors: Ian D Meng, David A BereiterAbstract:Meng, Ian D., James W. Hu, and David A. Bereiter. Differential effects of morphine on corneal-responsive neurons in rostral versus caudal regions of Spinal Trigeminal Nucleus in the rat. J. Neuroph...
-
encoding of corneal input in two distinct regions of the Spinal Trigeminal Nucleus in the rat cutaneous receptive field properties responses to thermal and chemical stimulation modulation by diffuse noxious inhibitory controls and projections to the
Journal of Neurophysiology, 1997Co-Authors: Ian D Meng, A P Benetti, David A BereiterAbstract:Meng, I. D., J. W. Hu, A. P. Benetti, and D. A. Bereiter. Encoding of corneal input in two distinct regions of the Spinal Trigeminal Nucleus in the rat: cutaneous receptive field properties, respon...
-
Differential distribution of Fos-like immunoreactivity in the Spinal Trigeminal Nucleus after noxious and innocuous thermal and chemical stimulation of rat cornea.
Neuroscience, 1996Co-Authors: I.d. Meng, David A BereiterAbstract:Abstract Corneal afferent nerves project to two spatially distinct sites within the Spinal Trigeminal Nucleus: the subNucleus interpolaris/caudalis transition and the subNucleus caudalis/upper cervical Spinal cord transition. The role of these two regions in processing corneal input is uncertain. To determine if neurons in these regions encode different features of an applied corneal stimulus, immunoreactivity for the immediate early gene protein product, Fos, was quantified in barbiturate-anesthetized rats. Intensity was varied across thermal (thermal probe 5, 35, 42, 52°C; radiant heat of ∼45°C) stimuli and compared with that seen after mustard oil (5 μl, 20%) or mineral oil application. All stimuli increased the number of Fos-positive neurons located at the ventrolateral pole of the subNucleus interpolaris/caudalis transition compared with unstimulated controls. By contrast, only 52°C thermal probe and mustard oil produced an additional peak of Fos-positive neurons within the superficial laminae at the subNucleus caudalis/cervical cord transition. Further, the magnitudes of the bimodal peaks of Fos produced by 52°C thermal probe and mustard oil stimuli were different quantitatively. Mustard oil caused a greater Fos response at the subNucleus interpolaris/caudalis transition than 52°C thermal probe stimulation, whereas the opposite was true at the subNucleus caudalis/cervical cord transition. Double-labeling revealed that Fos immunoreactive neurons within the Spinal Trigeminal Nucleus were restricted to regions densely labeled for calcitonin gene-related peptide. These results indicate that select features of corneal stimuli such as modality are encoded differently by neurons in the Trigeminal subNucleus interpolaris/caudalis transition compared with those located in the subNucleus caudalis/cervical cord transition. It is likely that neurons in these two brainstem regions subserve different aspects of corneal sensation.
-
Acute injection of adrenal steroids reduces cornea-evoked expression of c-fos within the Spinal Trigeminal Nucleus of adrenalectomized rats
Neuroscience, 1995Co-Authors: David A BereiterAbstract:The influence of transient increases in adrenal steroid hormones on the number of Fos-positive neurons after nociceptor activation was assessed in adrenalectomized rats. Fos protein, the product of the immediate early gene, c-fos, was detected immunocytochemically within the Spinal Trigeminal Nucleus 2 h after noxious thermal stimulation of the cornea. Adrenalectomized rats displayed an enhanced number of Fos-positive neurons within the caudal-most portions of Trigeminal subNucleus caudalis compared to that seen in adrenal-intact animals, an effect reversed by a single acute injection of corticosterone (1 mg/kg, i.p.) given 5 min prior to stimulation. Acute injection of the selective mineralocorticoid receptor agonist, aldosterone, or the selective glucocorticoid receptor agonist, RU28362, also reduced the number of Fos-positive neurons. Aldosterone and RU28362 had an additive effect on Fos when given concurrently. In contrast, adrenal status or acute injections of adrenal steroid receptor agonists had no effect on the number of Fos-positive neurons after corneal stimulation located within the ventrolateral pole of the Spinal Trigeminal Nucleus at the level of the subNucleus interpolaris/caudalis junction. Acute administration of adrenal steroids to adrenalectomized rats greatly attenuated the number of Fos-positive neurons seen after corneal stimulation within select portions of Trigeminal subNucleus caudalis. The contribution of both glucocorticoid and mineralocorticoid receptor subtypes in reducing Fos suggested a central site of action rather than an anti-inflammatory effect on peripheral tissue. These results are consistent with the hypothesis that transient increases in adrenal steroids, such as occur after injury, are sufficient to modify the production of Fos protein in central neurons that process nociceptive information.
-
Adrenalectomy enhances Fos-like immunoreactivity within the Spinal Trigeminal Nucleus induced by noxious thermal stimulation of the cornea
Neuroscience, 1993Co-Authors: Charles B. Hathaway, David A BereiterAbstract:Immunocytochemistry was used to assess the distribution of neurons within the Spinal Trigeminal Nucleus that expressed the protein product of the proto-oncogene c-fos after thermal stimulation of the cornea in barbiturate-anesthetized rats. The influence of adrenal steroids on Fos-like immunoreactivity induced by corneal stimulation also was examined by comparison of the results obtained in adrenal intact rats to those in adrenalectomized rats and to those in adrenalectomized rats given corticosterone replacement therapy. Stimuli (42 or 52 degrees C, 20 s per min, 15 min) were applied unilaterally to the cornea by a contact thermode. At 2 h after stimulation animals were perfused with 4% paraformaldehyde and tissue sections were incubated with primary antiserum against the Fos protein and processed with the avidin-biotin method. The pattern of Fos-like immunoreactivity after 52 degrees C stimulation revealed a dominant group of cells ipsilaterally within the superficial laminae of the caudalmost portion of Trigeminal subNucleus caudalis that was greatly enhanced in adrenalectomized rats. Low-intensity stimulation did not induce Fos-like immunoreactivity among cells in this caudal region. A second significant group of cells was seen more rostrally at periobex levels within the ventrolateral pole of the Nucleus. The number of cells in the periobex grouping was increased after 52 or 42 degrees C corneal stimulation when compared to unstimulated controls and was not affected by levels of corticosterone. The results indicated a discontinuous pattern of Fos-like immunoreactivity within the Spinal Trigeminal Nucleus after thermal stimulation of the cornea and a differential effect of adrenal steroids. The appearance of Fos-like immunoreactivity within caudal portions of the Nucleus was increased only by noxious intensities of stimulation and was further enhanced in animals with low levels of corticosterone. In contrast, the Fos-like immunoreactivity at periobex levels was increased after noxious and innocuous thermal stimuli and was independent of the level of corticosterone. The results were consistent with the hypothesis that glucocorticoids modify the expression of immediate early genes among a select group of central Trigeminal neurons. Such steroid modulation may contribute to the mechanisms that underlie long-term adaptation to noxious sensory input.
J L Molat - One of the best experts on this subject based on the ideXlab platform.
-
stimulus function wind up and modulation by diffuse noxious inhibitory controls of responses of convergent neurons of the Spinal Trigeminal Nucleus oralis
European Journal of Neuroscience, 1999Co-Authors: Radhouane Dallel, C Dualé, Philippe Luccarini, J L MolatAbstract:Extracellular unitary recordings were made from 53 Spinal Trigeminal Nucleus oralis (Sp5O) convergent neurons in halothane-anaesthetized rats. The neurons had an ipsilateral receptive field including mainly oral or perioral regions. They responded to percutaneous electrical stimulation with two peaks of activation. The first had a short latency (4.3 +/- 0.3 ms) and low threshold (0.35 +/- 0.04 mA), whereas the second had a longer latency (68.1 +/- 3.4 ms) and higher threshold (7.3 +/- 0.5 mA). Intracutaneous injection of capsaicin (0.1%) produced a strong and rapid reduction of the long-latency responses of Sp5O convergent neurons with little effect on the short-latency responses. In most cases (73%), the long-latency responses exhibited a wind-up phenomenon during repetitive (0.66 Hz) suprathreshold electrical stimulation. These results suggest that C-fibres mediate the long-latency response of Sp5O convergent neurons. Regarding the C-fibre-evoked responses, a linear relationship between the intensity of the applied current and the magnitude of the response was found within the one to three times threshold range. The Sp5O convergent neurons also encoded the intensity of mechanical stimuli applied to the skin or mucosa in the 5-50 g ranges. The evoked activity of Sp5O convergent neurons could be suppressed by noxious heat applied to the tail (52 degrees C) and long-lasting poststimulus effects followed this. These findings show that convergent neurons in the Sp5O resemble those in the deep laminae of the Spinal dorsal horn and Spinal Trigeminal Nucleus caudalis, and further support that the Sp5O plays a part in the processing of nociceptive information from the orofacial region.
-
Stimulus‐function, wind‐up and modulation by diffuse noxious inhibitory controls of responses of convergent neurons of the Spinal Trigeminal Nucleus oralis
The European journal of neuroscience, 1999Co-Authors: Radhouane Dallel, C Dualé, Philippe Luccarini, J L MolatAbstract:Extracellular unitary recordings were made from 53 Spinal Trigeminal Nucleus oralis (Sp5O) convergent neurons in halothane-anaesthetized rats. The neurons had an ipsilateral receptive field including mainly oral or perioral regions. They responded to percutaneous electrical stimulation with two peaks of activation. The first had a short latency (4.3 +/- 0.3 ms) and low threshold (0.35 +/- 0.04 mA), whereas the second had a longer latency (68.1 +/- 3.4 ms) and higher threshold (7.3 +/- 0.5 mA). Intracutaneous injection of capsaicin (0.1%) produced a strong and rapid reduction of the long-latency responses of Sp5O convergent neurons with little effect on the short-latency responses. In most cases (73%), the long-latency responses exhibited a wind-up phenomenon during repetitive (0.66 Hz) suprathreshold electrical stimulation. These results suggest that C-fibres mediate the long-latency response of Sp5O convergent neurons. Regarding the C-fibre-evoked responses, a linear relationship between the intensity of the applied current and the magnitude of the response was found within the one to three times threshold range. The Sp5O convergent neurons also encoded the intensity of mechanical stimuli applied to the skin or mucosa in the 5-50 g ranges. The evoked activity of Sp5O convergent neurons could be suppressed by noxious heat applied to the tail (52 degrees C) and long-lasting poststimulus effects followed this. These findings show that convergent neurons in the Sp5O resemble those in the deep laminae of the Spinal dorsal horn and Spinal Trigeminal Nucleus caudalis, and further support that the Sp5O plays a part in the processing of nociceptive information from the orofacial region.
-
Morphine microinjected into the Nucleus raphe magnus does not block the activity of Spinal Trigeminal Nucleus oralis convergent neurons in the rat.
Brain research, 1998Co-Authors: C Dualé, J L Molat, R DallelAbstract:This study investigated the effects of morphine microinjection into the Nucleus raphe magnus (RMg) on electrically evoked C-fiber activities of convergent neurons in the Spinal Trigeminal Nucleus oralis (Sp5O), in halothane-anesthetized rats. Although the neurons could be depressed by systemic morphine (6 mg/kg, i.v.) in a naloxone-reversible fashion, morphine microinjected into the RMg (2. 5 microgram or 5 microgram) neither depressed their C-fiber-evoked responses, nor the diffuse noxious inhibitory controls acting on them. It is concluded that the RMg is not involved in reinforcing descending inhibitory controls that are tonic or triggered by noxious stimuli acting on Sp5O convergent neurons.
-
morphine administered in the substantia gelatinosa of the Spinal Trigeminal Nucleus caudalis inhibits nociceptive activities in the Spinal Trigeminal Nucleus oralis
The Journal of Neuroscience, 1998Co-Authors: Radhouane Dallel, C Dualé, J L MolatAbstract:The present study investigates the effects of morphine microinjection into the Spinal Trigeminal Nucleus caudalis (Sp5C) or the Spinal Trigeminal Nucleus oralis (Sp5O) on C-fiber-evoked activities of Sp5O convergent neurons, after supramaximal percutaneous electrical stimulation in halothane-anesthetized rats. When it was microinjected into the Sp5O, morphine (2.5 m gi n 0.25 ml) never depressed the C-fiber-evoked responses of Sp5O convergent neurons (n 5 13), whereas these neurons were responsive to the inhibitory effects of systemic morphine (6 mg/kg, i.v.) in a naloxone-reversible manner. On the contrary, morphine microinjected into the Sp5C produced a naloxonereversible inhibition of the C-fiber-evoked responses of Sp5O neurons (n 5 14). The magnitude and the time course of this effect varied according to the location of the injection sites. After microinjection into the superficial laminae (n 5 7), a strong depressive effect of morphine (7 6 5% of control) on the C-fiber-evoked responses was apparent as soon as 5 min after the injection and could always be reversed by naloxone, administered either intravenously (0.4 mg/kg) or locally (2.5 m gi n 0.6 ml) at the same site as morphine. After microinjection into deeper laminae (V‐VI), a significant depressive effect (34 6 5% of control) of morphine could be detected only 20 min after the injection and was reversed only by intravenous administration of naloxone. These results suggest that morphine exerts its antinociceptive action on Sp5O convergent neurons by blocking the C-fiber inputs that relay in the Sp5C substantia gelatinosa. The mechanisms that underlie the activation of Sp5O convergent neurons by C-fibers and the inhibition of C-fiber-evoked responses of Sp5O convergent neurons by morphine microinjected into the Sp5C are discussed.
-
Effects of systemic morphine on the activity of convergent neurons of Spinal Trigeminal Nucleus oralis in the rat
European journal of pharmacology, 1996Co-Authors: Radhouane Dallel, J L Molat, Philippe Luccarini, Alain WodaAbstract:Abstract The Spinal Trigeminal Nucleus oralis has been shown to relay nociceptive inputs mainly from the oral and perioral regions. In this study, we examined the effects of intravenous administration of morphine on C-fiber-evoked activities of Spinal Trigeminal Nucleus oralis convergent neurons in halothane-anesthetized rats. Morphine depressed the C-fiber-evoked responses of Spinal Trigeminal Nucleus oralis convergent neurons in a dose-related (3–12 mg/kg range) and naloxone-reversible fashion. The ED 50 was 6.1 mg/kg, a dose similar to that found in the Spinal dorsal horn. The observed strong depressive action of morphine on noxious-evoked activities of Spinal Trigeminal Nucleus oralis neurons is consistent with our previous statement, based on electrophysiological studies, that this region plays an important role in the transmission of Trigeminal nociceptive information. The effect of morphine on the Spinal Trigeminal Nucleus oralis neurons is discussed in relation to its possible site and mechanism of action.
Alvin J Beitz - One of the best experts on this subject based on the ideXlab platform.
-
Distribution of nitric oxide synthase-immunoreactive interneurons in the Spinal Trigeminal Nucleus
The Journal of Comparative Neurology, 1994Co-Authors: C. S. Dohrn, Mary A. Mullett, R. H. Price, Alvin J BeitzAbstract:The Spinal Trigeminal Nucleus is involved in the transmission of orofacial sensory information. Neither the distribution of the neuromessenger, nitric oxide, within the Trigeminal system nor the possible relationship of this simple gas with trigeminothalamic neurons has been carefully studied. Using immunocytochemical (against nitric oxide synthase) and histochemical (NADPH-diaphorase staining) techniques, we have found that nitric oxide neurons and processes are more prominent in the Nucleus caudalis and the dorsomedial aspect of the Nucleus oralis than in other Spinal Trigeminal regions. To study the relationship of nitric oxide to trigeminothalamic neurons and interTrigeminal interneurons of the Spinal Trigeminal Nucleus, Spinal Trigeminal neurons were retrogradely labeled with fluorogold by thalamic injections or by injections into the junction of the Nucleus interpolaris and Nucleus caudalis. Medullary sections were subsequently processed with NADPH-diaphorase histochemistry. None of the diaphorase-stained neurons in the Spinal Trigeminal Nucleus was found to contain fluorogold; however, some diaphorase-stained processes were found in close proximity to trigeminothalamic neurons. Following Spinal Trigeminal Nucleus injections, many diaphorasestained neurons were found to contain fluorogold, especially in the Nucleus caudalis, suggesting that nitric oxide-containing neurons in the Spinal Trigeminal Nucleus are interTrigeminal interneurons. Collectively, these data indicate that nitric oxide is most prominent in interneurons located in Nucleus caudalis and that these interneurons give rise to processes that appose trigeminothalamic neurons, raising the possibility that they may indirectly influence orofacial nociceptive processing at the level of the Spinal Trigeminal Nucleus via nitric oxide production. © 1994 Wiley-Liss, Inc.
-
Distribution of nitric oxide synthase‐immunoreactive interneurons in the Spinal Trigeminal Nucleus
The Journal of comparative neurology, 1994Co-Authors: C. S. Dohrn, Mary A. Mullett, R. H. Price, Alvin J BeitzAbstract:The Spinal Trigeminal Nucleus is involved in the transmission of orofacial sensory information. Neither the distribution of the neuromessenger, nitric oxide, within the Trigeminal system nor the possible relationship of this simple gas with trigeminothalamic neurons has been carefully studied. Using immunocytochemical (against nitric oxide synthase) and histochemical (NADPH-diaphorase staining) techniques, we have found that nitric oxide neurons and processes are more prominent in the Nucleus caudalis and the dorsomedial aspect of the Nucleus oralis than in other Spinal Trigeminal regions. To study the relationship of nitric oxide to trigeminothalamic neurons and interTrigeminal interneurons of the Spinal Trigeminal Nucleus, Spinal Trigeminal neurons were retrogradely labeled with fluorogold by thalamic injections or by injections into the junction of the Nucleus interpolaris and Nucleus caudalis. Medullary sections were subsequently processed with NADPH-diaphorase histochemistry. None of the diaphorase-stained neurons in the Spinal Trigeminal Nucleus was found to contain fluorogold; however, some diaphorase-stained processes were found in close proximity to trigeminothalamic neurons. Following Spinal Trigeminal Nucleus injections, many diaphorasestained neurons were found to contain fluorogold, especially in the Nucleus caudalis, suggesting that nitric oxide-containing neurons in the Spinal Trigeminal Nucleus are interTrigeminal interneurons. Collectively, these data indicate that nitric oxide is most prominent in interneurons located in Nucleus caudalis and that these interneurons give rise to processes that appose trigeminothalamic neurons, raising the possibility that they may indirectly influence orofacial nociceptive processing at the level of the Spinal Trigeminal Nucleus via nitric oxide production. © 1994 Wiley-Liss, Inc.
C. S. Dohrn - One of the best experts on this subject based on the ideXlab platform.
-
Distribution of nitric oxide synthase-immunoreactive interneurons in the Spinal Trigeminal Nucleus
The Journal of Comparative Neurology, 1994Co-Authors: C. S. Dohrn, Mary A. Mullett, R. H. Price, Alvin J BeitzAbstract:The Spinal Trigeminal Nucleus is involved in the transmission of orofacial sensory information. Neither the distribution of the neuromessenger, nitric oxide, within the Trigeminal system nor the possible relationship of this simple gas with trigeminothalamic neurons has been carefully studied. Using immunocytochemical (against nitric oxide synthase) and histochemical (NADPH-diaphorase staining) techniques, we have found that nitric oxide neurons and processes are more prominent in the Nucleus caudalis and the dorsomedial aspect of the Nucleus oralis than in other Spinal Trigeminal regions. To study the relationship of nitric oxide to trigeminothalamic neurons and interTrigeminal interneurons of the Spinal Trigeminal Nucleus, Spinal Trigeminal neurons were retrogradely labeled with fluorogold by thalamic injections or by injections into the junction of the Nucleus interpolaris and Nucleus caudalis. Medullary sections were subsequently processed with NADPH-diaphorase histochemistry. None of the diaphorase-stained neurons in the Spinal Trigeminal Nucleus was found to contain fluorogold; however, some diaphorase-stained processes were found in close proximity to trigeminothalamic neurons. Following Spinal Trigeminal Nucleus injections, many diaphorasestained neurons were found to contain fluorogold, especially in the Nucleus caudalis, suggesting that nitric oxide-containing neurons in the Spinal Trigeminal Nucleus are interTrigeminal interneurons. Collectively, these data indicate that nitric oxide is most prominent in interneurons located in Nucleus caudalis and that these interneurons give rise to processes that appose trigeminothalamic neurons, raising the possibility that they may indirectly influence orofacial nociceptive processing at the level of the Spinal Trigeminal Nucleus via nitric oxide production. © 1994 Wiley-Liss, Inc.
-
Distribution of nitric oxide synthase‐immunoreactive interneurons in the Spinal Trigeminal Nucleus
The Journal of comparative neurology, 1994Co-Authors: C. S. Dohrn, Mary A. Mullett, R. H. Price, Alvin J BeitzAbstract:The Spinal Trigeminal Nucleus is involved in the transmission of orofacial sensory information. Neither the distribution of the neuromessenger, nitric oxide, within the Trigeminal system nor the possible relationship of this simple gas with trigeminothalamic neurons has been carefully studied. Using immunocytochemical (against nitric oxide synthase) and histochemical (NADPH-diaphorase staining) techniques, we have found that nitric oxide neurons and processes are more prominent in the Nucleus caudalis and the dorsomedial aspect of the Nucleus oralis than in other Spinal Trigeminal regions. To study the relationship of nitric oxide to trigeminothalamic neurons and interTrigeminal interneurons of the Spinal Trigeminal Nucleus, Spinal Trigeminal neurons were retrogradely labeled with fluorogold by thalamic injections or by injections into the junction of the Nucleus interpolaris and Nucleus caudalis. Medullary sections were subsequently processed with NADPH-diaphorase histochemistry. None of the diaphorase-stained neurons in the Spinal Trigeminal Nucleus was found to contain fluorogold; however, some diaphorase-stained processes were found in close proximity to trigeminothalamic neurons. Following Spinal Trigeminal Nucleus injections, many diaphorasestained neurons were found to contain fluorogold, especially in the Nucleus caudalis, suggesting that nitric oxide-containing neurons in the Spinal Trigeminal Nucleus are interTrigeminal interneurons. Collectively, these data indicate that nitric oxide is most prominent in interneurons located in Nucleus caudalis and that these interneurons give rise to processes that appose trigeminothalamic neurons, raising the possibility that they may indirectly influence orofacial nociceptive processing at the level of the Spinal Trigeminal Nucleus via nitric oxide production. © 1994 Wiley-Liss, Inc.
-
NMDA receptor mRNA expression in NOS-containing neurons in the Spinal Trigeminal Nucleus of the rat.
Neuroscience Letters, 1994Co-Authors: C. S. Dohrn, Al J BeitzAbstract:The Spinal Trigeminal Nucleus (STN) is involved in the transmission of orofacial sensory information. Nitric oxide (NO), an important neuromessenger, and the glutamate receptor subtype, NMDA NR1, have been implicated in nociception in the STN. However, the anatomical relationship of NO and NMDA NR1 has not been investigated within this Nucleus. Using both immunocytochemical (against NO synthase; NOS) and in situ hybridization studies of NMDA NR1 receptor mRNA, we found that NOS-containing neurons in the STN expressed more mRNA for NR1 than did non-NOS-containing neurons in the STN. These data suggest that NMDA activation may lead to NO production in the STN and is consistent with previous studies, implicating both NMDA and NO in nociception.