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We studied by immunocytochemistry the expression of adrenomedullin (AM) in the human medulla oblongata, sampled from 13 adult subjects (mean age: 38 years), whose medical history was negative for neurological and neurovascular pathologies. Immunoreactive neurons were found in the medulla oblongata with statistically significant differences among the various nuclei (one-way ANOVA, P < 0.001). The hypoglossal nucleus showed higher AM expression than that of the spinal tract of the trigeminal nerve (P < 0.05), solitary tract nucleus (P < 0.05), nucleus intercalatus (P < 0.05), and area postrema (P < 0.05). The arcuate nucleus and inferior olivary nuclear complex showed lower AM expression than the hypoglossal nucleus (P < 0.001), vestibular nuclei (P < 0.01), cuneate and gracile nuclei (P < 0.05), lateral column of the reticular formation (P < 0.05), and nucleus ambiguous (P < 0.05). Furthermore the nuclei were grouped with reference to their function, into somatic sensitive nuclei, somatic motor nuclei, visceral nuclei, reticular formation, and nuclei involved in cerebellar functions. The ANOVA revealed statistically significant differences (P < 0.001) in mean AM scores among the different groups. Nuclei involved in cerebellar function showed the lowest mean AM score (P < 0.05). The difference in AM score between somatic motor nuclei and visceral nuclei was also statistically significant (P < 0.05). Widespread AM immunoreactivity in the nuclei of the medulla oblongata may account for the role of the peptide in neuronal function and regulation of regional blood flow. Differences in the expression of AM in the nuclei studied indicate the different involvement of AM in neurotransmission and neuromodulation.  相似文献   

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Lorke DE  Kwong WH  Chan WY  Yew DT 《Life sciences》2003,73(10):1315-1331
Distribution and maturation of catecholaminergic (CA) neurons have been studied by tyrosine hydroxylase immunohistochemistry in the medulla oblongata of human fetuses aged 14.5-25 weeks of gestation. Already at 14.5 weeks, CA neurons were observed in two longitudinally oriented cell clusters, one located ventrolaterally in the area of the lateral reticular and ambiguous nuclei, the other one dorsomedially forming 4 groups related to the dorsal vagal nucleus, the commissural nucleus of the vagus, the nucleus of the tractus solitarius and the area postrema. CA neurons in the area postrema were often found close to blood vessels. Scattered intermediate CA neurons were seen between these two larger clusters. CA neurons still appeared immature exhibiting bipolar morphology with only one or two short stout processes, which hardly branched. At 21 weeks, CA neurons occupied essentially the same location, but had a more mature morphology. Though still bipolar in shape, they had thinner and much longer processes which frequently branched. Both in the ventrolateral and the dorsomedial cell clusters, these processes were frequently lying close to blood vessels. At 25 weeks, CA cells had matured into multipolar neurons with long thin processes forming fine fiber networks in the ventrolateral medulla as well as around and within the dorsal vagal and solitarius nuclei. Only at this stage, a distinct CA fiber tract was seen located in the region of the tractus solitarius. Our results indicate that CA neurons in the human medulla, which are presumably involved in the control of ventilation and blood pressure, though generated rather early during development, mature relatively late.  相似文献   

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Four types of neurons distinguished by NADPH-diaphorase reaction have been identified in seven nuclei of human and rat medulla oblongata. It was found that nitrogen oxide (NO)-positive neurons had similar distributions; neurons with high NO-synthase activity predominated in vasomotor nuclei and, in sensitive nuclei, most neurons had low NO-syntase activity.  相似文献   

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The nucleus tractus solitarii (NTS) is a brain stem center mediating depression of blood pressure. In order to elucidate a possible mechanism for the central regulation of blood pressure, we studied noradrenergic indices in the medulla oblongata, a region including the NTS, in spontaneously hypertensive rats (SHR) as compared with normotensive controls of the Wistar Kyoto strain (WKY) at 12 weeks of age. The medulla oblongata was the only brain region showing a significantly low noradrenaline level in the SHR as compared with WKY rats; the level is also significantly decreased at 8 weeks of age. The alpha 1-adrenergic binding sites, as measured with 2-(2, 6-dimethoxy) phenoxyethylamine-methylbenzodioxan [3H]WB4101 showed significant increases inK D andB max values in medulla oblongata homogenates from rats of both strains from 4–12 weeks after birth, with no significant interstrain difference. On the other hand, theK D andB max of the alpha 2-sites, measured by [3H]yohimbine binding, were reduced in SHR as compared to WKY animals, even at 4 weeks after birth when hypertension was not yet apparent. As expected, the relatively selective alpha 2-antagonist, clonidine, was a potent inhibitor of [3H]yohimbine binding but not of [3H]WB4101 binding in these homogenates. The results suggest that some genetic disorder in the alpha 2-adrenergic transmission system in the NTS region may be involved in the development of hypertension in the SHR rats.Dedicated to Professor Yasuzo Tsukada.  相似文献   

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It was established as a result of a laminar analysis of evoked potentials (EP) in the paramedian lobe of the cerebellum of unanesthetized cats that in response to stimulation of the lateral reticular nucleus (LRN) excitation of granulosa cells develops which is not accompanied by excitation of Purkinje cells. Destruction of the lateral nucleus leads to a considerable decrease in the "diffuse" component of the EP which develop during stimulation of the somatic nerves. The results obtained show that the afferent pathway whose fibers innervate granulosa cells of a special type, which have been previously described, passes through the LRN. These cells have extensive receptive fields and do not directly affect the activity of Purkinje cells. A hypothesis is proposed on the basis of the results obtained and data in the literature that the extensive receptive fields of the LRN cells and of the granulosa cells innervated by them are due to interneuronal connections within the lateral nucleus.Institute of Problems of Information Transmission, Academy of Sciences of the USSR, Moscow. Laboratory on the Use of Mathematical Methods in Biology, Moscow University. Translated from Neirofiziologiya, Vol. 2, No. 6, pp. 581–586, November–December, 1970.  相似文献   

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Local injection of substance P (SP) into the ventral portion of the nucleus gigantocellularis, nucleus reticularis lateralis, and nucleus retrofacialis of the ventrolateral medulla oblongata (VLM) or direct application on the ventral surface of the medulla oblongata caused marked stimulation of tidal volume (VT) and/or minute ventilation (VE). The ventilatory response to hypoxia was significantly blunted after SP in the VLM but not in the dorsal medulla oblongata (DM) (nucleus tractus solitarius). The SP antagonist [D-Pro2,D-Trp7,9]SP almost completely inhibited this response when applied locally to a wide area of the superficial layer of the VLM but not of the DM. Unilateral or bilateral application of 0.3-1.5 nmol of the SP antagonist in the VLM (corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment) markedly attenuated the response to a 5% CO2 inhalation. The inhibition of the CO2 response was seen after [D-Pro2,D-Trp7,9]SP in the rostral areas of the medulla oblongata corresponding to the corpus trapezoideum and the caudal region extending from the rootlets of the nucleus hypoglossus to the first cervical segment of the cervical cord. Electric somatosensory-induced ventilatory stimulation could be depressed by approximately 70% by [D-Pro2,D-Trp7,9]SP locally applied on the surface of the VLM. We conclude that SP is involved in the hypoxic, hypercapnic, and somatosensory ventilatory responses in the rat. However, these respiratory reflexes are mediated via different neuronal pools in the medulla oblongata, mainly the VLM.  相似文献   

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Glycine immunoreactive neurons in the medulla oblongata in cats   总被引:1,自引:0,他引:1  
Using a highly specific antiserum to Glycine and a very sensitive immunohistochemical technique with streptavidin-HRP, we visualized for the first time a considerable number of glycine immunoreactive cell bodies and fibers in the cat medulla oblongata. These results suggest that glycine may play an essential role in nearly all the physiological functions involving the medulla oblongata, including the muscular atonia occurring during paradoxical sleep.  相似文献   

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An anatomic atlas of the goat brain stem was developed for use in studies that analyze medullary neuronal groups, and factors that influence variability in the location of neuronal groups were determined. The medullas of 31 adult goats (weight, 17-88 kg) were fixed, harvested, frozen, serially sectioned, stained with 0.5% neutral red, and examined with a light microscope. Obex, the point at which the central canal opens into the fourth ventricle, was taken as the zero reference point from which the rostrocaudal and mediolateral coordinates of medullary neuronal groups were determined, whereas dorsoventral coordinates were calculated from the medullary surface. Histological variations with goat body weight were quantified, and linear regression analysis provided adjustment factors for weight in all three dimensions. Similar analysis of percentage of shrinkage on fixation and processing provided adjustment factors for precise coordinates of medullary neuronal groups. For accurate location of neuronal groups, body weight and histological procedure should be taken into account. The present study provided adjustment factors for body weight and standard histological processing to locate most major medullary neuronal groups in the adult goat.  相似文献   

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Complete serial sectioning of the medulla oblongata in monkey, cat, guinea pig, and japanese dancing mouse and incubation for somatostatin-immunoreaction was carried out. Numerous regions of the medulla oblongata such as the nucleus reticularis gigantocellularis, nucleus cuneatus et gracillis, nucleus raphe magnus, nucleus tractus solitarius, nucleus vestibularis, and parts of the oliva contain dense networks of somatostatin-immunoreactive nerve fibers. Cell bodies were seen in the nucleus reticularis medullae oblongatae. In the spinal cord the sections from each segment were analyzed, showing the highest concentrations of somatostatinergic fibers in the substantia gelantinosa of the columna dorsalis. Cell bodies were seen in the zona intermedia centralis, especially in the upper cervical segments. Many positive fibers were also seen in the entire zona intermedia and the columna ventralis. Especially prominent was the immunoreactivity in the zona intermediolateralis of the thoracic segments and the columna ventralis of the lower lumbar and sacral segments.  相似文献   

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In the normal as well as in the oxygen deficiency conditions the research has been conducted to study the influence of associative mediodorsal (MD) nucleus of thalamus on impulsive activity of respiratory neurons of medulla oblongata of respiration. In conditions of normal atmospheric pressure, before the uplift of the animals, the electrical stimulation of MD of nucleus of thalamus has had mainly inhibiting influence. In the initial phase, on 4-5 thousand meter altitude, activation of frequent discharge of neurons occurred, the respiration has become frequent as well. In this situation the inhibiting influence of stimulation of MD nucleus of thalamus was more accentuated than in conditions of normoxia. In the second phase, 7.5-8 thousand meters, the opposite occurred, i.e. reduction of respiratory center activity of medulla oblongata and thalamus. In this difficult conditions of hypoxia, a reduction of impulsive activity of neurons has been observed; the respiration was becoming slower and surface. Meanwhile, the inhibiting influence of thalamus was not significant.  相似文献   

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The effect of substance P (SP) and the SP antagonist [D-Pro2,D-Trp7,9]-SP on basal ventilation was investigated in halothane-anesthetized rats. Microinjections of SP (0.4-1.5 nmol) into the ventrolateral medulla oblongata (VLM), (nuclei gigantocellularis, facialis, ambiguus, and reticularis lateralis) or into the dorsomedial medulla oblongata (DM, nucleus tractus solitarius) and its ventral surroundings dose dependently increased tidal volume (VT) and/or minute ventilation. In sensitive areas, the ventilatory stimulation was initiated within minutes, peaked around 8-10 min, and slowly returned to normal over 30-45 min after the injection. In the VLM sites, the increase in VT was generally accompanied by a decrease in respiratory frequency (f), whereas in the DM, f increased in parallel with VT. Furthermore, within the VLM, the respiratory response patterns differed with the definite location of the SP injection. A shortening of inspiratory time was observed in the ventromedial part, the ventrolateral portion of the nucleus paragigantocellularis and ventral to the nucleus facialis. In contrast, a lengthening of expiratory time was seen when SP was injected or applied more laterally along the ventral portion of nucleus facialis and near or directly on the ventral medullary surface. Application of [D-Pro2, D-Trp7,9]SP before or after SP completely antagonized the excitatory effects of SP on ventilation. The SP antagonist administered into the VLM decreased the ventilatory response to hypoxic breathing but caused no change during hyperoxic conditions.  相似文献   

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Summary The immunohistochemical localization of neuropeptide Y (NPY) was correlated with those of dopamine--hydroxylase (DBH) and vasoactive intestinal polypeptide (VIP) by mapping serial 7 m paraffin sections at three levels of the guina pig lower brainstem: a) area postrema, b) dorsal motor nucleus of the vagus, and c) nucleus prepositus of the hypoglossal nerve. Based on differences in transmitter expression, three populations of NPY-immunoreactive (IR) neurons were distinguished: NPY-IR catecholaminergic cells (NPY/CA), NPY-IR VIP-ergic cells (NPY/VIP), and NPY-IR cells which were not reactive to either DBH or VIP. Within these populations, size differences among neurons in characteristic locations allowed differentiation among the following subpopulations: NPY/CA neurons in the lateral reticular nucleus — magnocellular part (mean neuronal size 538 m2) and parvocellular part (318 m2)-, in the vagus-solitarius complex (433 m2), and in the dorsal strip (348 m2); NPY/VIP neurons in the vagus-solitarius complex (368 m2) and in the nucleus ovalis (236 m2). Apart from scattered NPY-IR cell bodies in the regions listed above, NPY-IR cell bodies in the lateral portion of the nucleus solitarius and in the caudal part of the spinal nucleus of the trigeminal nerve did not exhibit IR to either DBH or VIP. NPY-IR neurons in the area postrema occurred too infrequently for co-localization studies. The differential distribution of heterogeneous NPY-IR cell subpopulations may reflect the involvement of NPY in a variety of neuronal functions.Supported by the Deutsche Forschungsgemeinschaft, grant He 919/6-1  相似文献   

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