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Hypoglossal Nucleus (hypoglossal + nucleus)
Selected AbstractsImmunohistochemical Characterization of Neurones in the Hypoglossal Nucleus of the PigANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010W. Sienkiewicz Summary With 4 figures and 1 table In this study, the presence of several neurotransmitters and transmitter synthesizing enzymes was studied in hypoglossal nucleus (HN) of the juvenile (4 months old) female pigs (n = 3). Double-labeling immunofluorescence revealed neurones expressing cholinacetyltranspherase (ChAT), calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), and somatostatin (SOM). Nerve fibers within HN were ChAT, CGRP, NOS, SOM, substance P (SP), Leu-5-enkephalin (Leu-5-Enk), ß-dopamine hydroxylase (DßH), neuropeptide Y (NPY) positive. Virtually all the perikarya contained ChAT, whereas CGRP was present in 47% of the neurones. Nerve cell bodies containing NOS or SOM were only occasionally observed. Immunoreactive nerve fibers were found in a close vicinity of the perikarya, often forming baskets around nerve cell bodies. The results obtained were compared with similar data obtained in other species. The presence of immunoreactive structures, origin of the nerve fibers, and functional significance of the findings are discussed. [source] In vivo Distribution of Bismuth in the Mouse Brain: Influence of Long-Term Survival and Intracranial Placement on the Uptake and Transport of Bismuth in Neuronal TissueBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2005Agnete Larsen In medicine, bismuth-compounds have long been used to remedy gastrointestinal disorders; lately in combination with antibiotics to treat Helicobacter pylori associated peptic ulcers. An epidemic episode of bismuth-induced encephalopathy in France in the 1970s revealed the neurotoxic potential of bismuth. This incidence, involving almost 1000 patients, remains unexplained and the contribution of other factors besides bismuth has been postulated. Recently an autometallographic technique made it possible to detect bismuth in morphologically intact tissue. In the present study, autometallographicly detectable bismuth was seen throughout the brain following intraperitoneal and intracranial exposure. The neuronal staining pattern seems highly organized with some areas heavily stained and others with low or no staining. Long-term (8 months) intraperitoneal exposure led to higher bismuth uptake than short-term (2 weeks) exposure. Following both intraperitoneal and intracranial exposure, high amounts of bismuth were found in the reticular and hypothalamic nuclei, in the oculomotor and hypoglossal nuclei and in Purkinje cells. Within the central nervous system (CNS) retrograde axonal transport was seen after intracranial bismuth exposure. Axonal transport seems to influence the distribution of bismuth as the highest uptake of bismuth after intraperitoneal exposure was seen in the facial and the trigeminal motor nuclei, i.e. neurones with processes outside the blood-brain barrier, whereas these nuclei contained no bismuth following ic exposure. Ultrastructurally, accumulation of bismuth was seen in lysosomes. [source] Evidence for species differences in the pattern of androgen receptor distribution in relation to species differences in an androgen-dependent behaviorDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2002Brian K. Shaw Abstract Chickens (Gallus gallus domesticus) and Japanese quail (Coturnix japonica), two closely related gallinaceous bird species, exhibit a form of vocalization,crowing,which differs between the species in two components: its temporal acoustic pattern and its accompanying postural motor pattern. Previous work utilizing the quail-chick chimera technique demonstrated that the species-specific characteristics of the two crow components are determined by distinct brain structures: the midbrain confers the acoustic pattern, and the caudal hindbrain confers the postural pattern. Crowing is induced by androgens, acting directly on androgen receptors. As a strategy for identifying candidate neurons in the midbrain and caudal hindbrain that could be involved in crow production, we performed immunocytochemistry for androgen receptors in these brain regions in both species. We also investigated midbrain-to-hindbrain vocal-motor projections. In the midbrain, both species showed prominent androgen receptor immunoreactivity in the nucleus intercollicularis, as had been reported in previous studies. In the caudal hindbrain, we discovered characteristic species differences in the pattern of androgen receptor distribution. Chickens, but not quail, showed strong immunoreactivity in the tracheosyringeal division of the hypoglossal nucleus, whereas quail, but not chickens, possessed strong immunoreactivity in a region of the ventrolateral medulla. Some of these differences in hindbrain androgen receptor distribution may be related to the species differences in the postural component of crowing behavior. The results of the present study imply that the spatial distribution of receptor proteins can vary even between closely related species. Such variation in receptor distribution could underlie the evolution of species differences in behavior. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 203,220, 2002 [source] The nitric oxide/cyclic guanosine monophosphate pathway modulates the inspiratory-related activity of hypoglossal motoneurons in the adult ratEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2008Fernando Montero Abstract Motoneurons integrate interneuronal activity into commands for skeletal muscle contraction and relaxation to perform motor actions. Hypoglossal motoneurons (HMNs) are involved in essential motor functions such as breathing, mastication, swallowing and phonation. We have investigated the role of the gaseous molecule nitric oxide (NO) in the regulation of the inspiratory-related activity of HMNs in order to further understand how neural activity is transformed into motor activity. In adult rats, we observed nitrergic fibers and bouton-like structures in close proximity to motoneurons, which normally lack the molecular machinery to synthesize NO. In addition, immunohistochemistry studies demonstrated that perfusion of animals with a NO donor resulted in an increase in the levels of cyclic guanosine monophosphate (cGMP) in motoneurons, which express the soluble guanylyl cyclase (sGC) in the hypoglossal nucleus. Modulators of the NO/cGMP pathway were micro-iontophoretically applied while performing single-unit extracellular recordings in the adult decerebrated rat. Application of a NO synthase inhibitor or a sGC inhibitor induced a statistically significant reduction in the inspiratory-related activity of HMNs. However, excitatory effects were observed by ejection of a NO donor or a cell-permeable analogue of cGMP. In slice preparations, application to the bath of a NO donor evoked membrane depolarization and a decrease in rheobase, which were prevented by co-addition to the bath of a sGC inhibitor. These effects were not prevented by reduction of the spontaneous synaptic activity. We conclude that NO from afferent fibers anterogradely modulates the inspiratory-related activity of HMNs by a cGMP-dependent mechanism in physiological conditions. [source] Neuronal and vascular localization of histamine N-methyltransferase in the bovine central nervous systemEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2000Masahiro Nishibori Abstract Histamine N-methyltransferase (HMT) (EC 2.1.1.8) plays a crucial role in the inactivation of the neurotransmitter histamine in the CNS. However, the localization of HMT remains to be determined. In the present study, we investigated immunohistochemical localization of HMT in the bovine CNS using a polyclonal antibody against bovine HMT. The HMT-like immunoreactivity was observed mainly in neurons. Strongly immunoreactive neurons were present in the oculomotor nucleus and ruber nucleus in the midbrain, the facial nucleus in the pons, the dorsal vagal nucleus and hypoglossal nucleus in the medulla oblongata and in the anterior horn as well as intermediolateral zone of the spinal cord. Intermediately immunoreactive neurons were present in the piriform cortex and the inferior olivary nucleus. The grey matter of the forebrain regions was diffusely and faintly stained. In the cerebellum and the striatum, the nerve fibres in the white matter were positive. The tuberomammillary nucleus, where histaminergic neurons are present, were weakly positive. The other immunoreactive structures in the CNS were blood vessels. Almost all of the blood vessel walls, irrespective of whether they were arterial or venous, were variably stained. The glial fibrillary acidic protein- (GFAP-) immunoreactive astrocytes were not stained. These findings indicated that histamine released from histaminergic nerve terminals or varicose fibres is methylated mainly in postsynaptic or extrasynaptic neurons rather than in astrocytes. The localization of HMT in the blood vessel wall may mean that blood-borne histamine and histamine released from mast cells associated with the blood vessels are catabolized in this structure. [source] Uncoupling of rhythmic hypoglossal from phrenic activity in the ratEXPERIMENTAL PHYSIOLOGY, Issue 6 2004Walter M. St.-John During eupnoea, rhythmic motor activities of the hypoglossal, vagal and phrenic nerves are linked temporally. The inspiratory discharges of the hypoglossal and vagus motor neurones commence before the onset of the phrenic burst. The vagus nerve also discharges in expiration. Upon exposure to hypocapnia or hypothermia, the hypoglossal discharge became uncoupled from that of the phrenic nerve. This uncoupling was evidenced by variable times of onset of hypoglossal discharge before or after the onset of phrenic discharge, extra bursts of hypoglossal activity in neural expiration, or complete absence of any hypoglossal discharge during a respiratory cycle. No such changes were found for vagal discharge, which remained linked to the phrenic bursts. Intracellular recordings in the hypoglossal nucleus revealed that all changes in hypoglossal discharge were due to neuronal depolarization. These results add support to the conclusion that the brainstem control of respiratory-modulated hypoglossal activity differs from control of phrenic and vagal activity. These findings have implications for any studies in which activity of the hypoglossal nerve is used as the sole index of neural inspiration. Indeed, our results establish that hypoglossal discharge alone is an equivocal index of the pattern of overall ventilatory activity and that this is accentuated by hypercapnia and hypothermia. [source] Human brain aminopeptidase A: biochemical properties and distribution in brain nucleiJOURNAL OF NEUROCHEMISTRY, Issue 1 2008Nadia De Mota Abstract Aminopeptidase A (APA) generated brain angiotensin III, one of the main effector peptides of the brain renin angiotensin system, exerting a tonic stimulatory effect on the control of blood pressure in hypertensive rats. The distribution of APA in human brain has not been yet studied. We first biochemically characterized human brain APA (apparent molecular mass of 165 and 130 kDa) and we showed that the human enzyme exhibited similar enzymatic characteristics to recombinant mouse APA. Both enzymes had similar sensitivity to Ca2+. Kinetic studies showed that the Km (190 ,mol/L) of the human enzyme for the synthetic substrate- l -glutamyl-,-naphthylamide was close from that of the mouse enzyme (256 ,mol/L). Moreover, various classes of inhibitors including the specific and selective APA inhibitor, (S)-3-amino-4-mercapto-butyl sulfonic acid, had similar inhibitory potencies toward both enzymes. Using (S)-3-amino-4-mercapto-butyl sulfonic acid, we then specifically measured the activity of APA in 40 microdissected areas of the adult human brain. Significant heterogeneity was found in the activity of APA in the various analyzed regions. The highest activity was measured in the choroids plexus and the pineal gland. High activity was also detected in the dorsomedial medulla oblongata, in the septum, the prefrontal cortex, the olfactory bulb, the nucleus accumbens, and the hypothalamus, especially in the paraventricular and supraoptic nuclei. Immunostaining of human brain sections at the level of the medulla oblongata strengthened these data, showing for the first time a high density of immunoreactive neuronal cell bodies and fibers in the motor hypoglossal nucleus, the dorsal motor nucleus of the vagus, the nucleus of the solitary tract, the Roller nucleus, the ambiguus nucleus, the inferior olivary complex, and in the external cuneate nucleus. APA immunoreactivity was also visualized in vessels and capillaries in the dorsal motor nucleus of the vagus and the inferior olivary complex. The presence of APA in several human brain nuclei sensitive to angiotensins and involved in blood pressure regulation suggests that APA in humans is an integral component of the brain renin angiotensin system and strengthens the idea that APA inhibitors could be clinically tested as an additional therapy for the treatment of certain forms of hypertension. [source] Guidelines for the pathoanatomical examination of the lower brain stem in ingestive and swallowing disorders and its application to a dysphagic spinocerebellar ataxia type 3 patientNEUROPATHOLOGY & APPLIED NEUROBIOLOGY, Issue 1 2003U. Rüb U. Rüb, E. R. Brunt, D. Del Turco, R. A. I. de Vos, K. Gierga, H. Paulson and H. Braak (2003) Neuropathology and Applied Neurobiology 29, 1,13 Guildelines for the pathoanatomical examination of the lower brain stem in ingestive and swallowing disorders and its application to a dysphagic spinocerebellar ataxia type 3 patient Despite the fact that considerable progress has been made in the last 20 years regarding the three-phase process of ingestion and the lower brain stem nuclei involved in it, no comprehensive descriptions of the ingestion-related lower brain stem nuclei are available for neuropathologists confronted with ingestive malfunctions. Here, we propose guidelines for the pathoanatomical investigation of these nuclei based on current knowledge with respect to ingestion and the nuclei responsible for this process. The application of these guidelines is described by drawing upon the example of the lower brain stem of a male patient with spinocerebellar ataxia type 3, also known as Machado-Joseph disease, who displayed malfunctions during the preparatory phase of ingestion, as well as lingual and pharyngeal phases of swallowing. By way of the representative application of the recommended investigation procedure to 100 µm serial sections through the patient's brain stem stained for lipofuscin pigment and Nissl material, we observed neuronal loss together with astrogliosis in nearly all of the ingestion-related lower brain stem nuclei (motor, principal and spinal trigeminal nuclei; facial nucleus; parvocellular reticular nucleus; ambiguus nucleus, motor nucleus of the dorsal glossopharyngeal and vagal area; gelatinous, medial, parvocellular and pigmented solitary nuclei; hypoglossal nucleus). In view of their known functional role in the three-phase process of ingestion, damage to these nuclei not only offers an explanation of the patient's malfunctions related to the preparatory phase of ingestion and lingual and pharyngeal phases of swallowing, but also suggests that the patient may have suffered from additional esophageal phase swallowing malfunctions not mentioned in his medical records. [source] Transgenic neuronal nitric oxide synthase expression induces axotomy-like changes in adult motoneuronsTHE JOURNAL OF PHYSIOLOGY, Issue 18 2010Fernando Montero Dysregulation of protein expression, function and/or aggregation is a hallmark of a number of neuropathological conditions. Among them, upregulation and/or de novo expression of the neuronal isoform of nitric oxide (NO) synthase (nNOS) commonly occurs in diverse neurodegenerative diseases and in axotomized motoneurons. We used adenoviral (AVV) and lentiviral (LVV) vectors to study the effects of de novo nNOS expression on the functional properties and synaptic array of motoneurons. AVV-nNOS injection into the genioglossus muscle retrogradely transduced neonatal hypoglossal motoneurons (HMNs). Ratiometric real-time NO imaging confirmed that transduced HMNs generated NO gradients in brain parenchyma (space constant: ,12.3 ,m) in response to a glutamatergic stimulus. Unilateral AVV-nNOS microinjection in the hypoglossal nucleus of adult rats induced axotomy-like changes in HMNs. Specifically, we found alterations in axonal conduction properties and the recruitment order of motor units and reductions in responsiveness to synaptic drive and in the linear density of synaptophysin-positive puncta opposed to HMN somata. Functional alterations were fully prevented by chronic treatment with nNOS or soluble guanylyl cyclase inhibitors. Synaptic and functional changes were also completely avoided by prior intranuclear injection of a neuron-specific LVV system for miRNA-mediated nNOS knock-down (LVV-miR-shRNA/nNOS). Furthermore, synaptic and several functional changes evoked by XIIth nerve injury were to a large extent prevented by intranuclear administration of LVV-miR-shRNA/nNOS. We suggest that nNOS up-regulation creates a repulsive NO gradient for synaptic boutons underlying most of the functional impairment undergone by injured motoneurons. This further strengthens the case for nNOS targeting as a plausible strategy for treatment of peripheral neuropaties and neurodegenerative disorders. [source] Immunohistochemical Characterization of Neurones in the Hypoglossal Nucleus of the PigANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2010W. Sienkiewicz Summary With 4 figures and 1 table In this study, the presence of several neurotransmitters and transmitter synthesizing enzymes was studied in hypoglossal nucleus (HN) of the juvenile (4 months old) female pigs (n = 3). Double-labeling immunofluorescence revealed neurones expressing cholinacetyltranspherase (ChAT), calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), and somatostatin (SOM). Nerve fibers within HN were ChAT, CGRP, NOS, SOM, substance P (SP), Leu-5-enkephalin (Leu-5-Enk), ß-dopamine hydroxylase (DßH), neuropeptide Y (NPY) positive. Virtually all the perikarya contained ChAT, whereas CGRP was present in 47% of the neurones. Nerve cell bodies containing NOS or SOM were only occasionally observed. Immunoreactive nerve fibers were found in a close vicinity of the perikarya, often forming baskets around nerve cell bodies. The results obtained were compared with similar data obtained in other species. The presence of immunoreactive structures, origin of the nerve fibers, and functional significance of the findings are discussed. [source] Increased neuronal cell number in the dorsal motor nucleus of the vagus in schizophreniaACTA NEUROPSYCHIATRICA, Issue 1 2010Hubertus Axer Axer H, Bernstein H-G, Keiner S, Heronimus P, Sauer H, Witte OW, Bogerts B, Bär K-J. Increased neuronal cell number in the dorsal motor nucleus of the vagus in schizophrenia. Objective: Recently, a reduction in efferent vagal regulation has been found in schizophrenic patients. Methods: Therefore, the brainstems of nine schizophrenic patients and nine normal controls were stereologically analysed. The number of neurons using the optical fractionator method and nuclear volumes applying the Cavalieri principle was estimated in Nissl stained sections of the dorsal motor nucleus of the vagus (DMNV) and the hypoglossal nucleus. Results: The neurons in the right DMNV were significantly increased in the schizophrenic group compared to normal controls (p = 0.047), while the volumes of the DMNV did not differ. In contrast, no such differences were found in the hypoglossal nucleus. Conclusion: Although this pilot study is limited by its small sample size, the analysis of the solitarius,ambiguus,vagus system in schizophrenic patients is an interesting target in schizophrenia research. The most reasonable background for increased neuron numbers in the DMNV could be a system-specific neurodevelopmental disturbance in schizophrenia. [source] | ||||||||||||||||||||||