Different astroglial reaction between the vagal dorsal motor nucleus and nucleus ambiguus following vagal–hypoglossal nerve anastomosis in cats

2000 ◽  
Vol 881 (2) ◽  
pp. 222-226 ◽  
Author(s):  
Chyn-Tair Lan ◽  
Jiang Chuan Liu ◽  
Jee-Ching Hsu ◽  
Eng-Ang Ling
2003 ◽  
Vol 458 (2) ◽  
pp. 195-207 ◽  
Author(s):  
Chyn-Tair Lan ◽  
Jee-Ching Hsu ◽  
Chen-Nen Chang ◽  
Huo-Li Chuang ◽  
Eng-Ang Ling

2005 ◽  
Vol 98 (4) ◽  
pp. 1442-1457 ◽  
Author(s):  
Qiuli Liu ◽  
Margaret T. T. Wong-Riley

Previously, we reported that the expression of cytochrome oxidase in a number of brain stem nuclei exhibited a plateau or reduction at postnatal day (P) 3–4 and a dramatic decrease at P12, against a general increase with age. The present study examined the expression of glutamate, N-methyl-d-aspartate receptor subunit 1 (NMDAR1), GABA, GABAB receptors, glycine receptors, and glutamate receptor subunit 2 (GluR2) in the ventrolateral subnucleus of the solitary tract nucleus, nucleus ambiguus, hypoglossal nucleus, medial accessory olivary nucleus, dorsal motor nucleus of the vagus, and cuneate nucleus, from P2 to P21 in rats. Results showed that 1) the expression of glutamate increased with age in a majority of the nuclei, whereas that of NMDAR1 showed heterogeneity among the nuclei; 2) GABA and GABAB expressions decreased with age, whereas that of glycine receptors increased with age; 3) GluR2 showed two peaks, at P3–4 and P12; and 4) glutamate and NMDAR1 showed a significant reduction, whereas GABA, GABAB receptors, glycine receptors, and GluR2 exhibited a concomitant increase at P12. These features were present but less pronounced in hypoglossal nucleus and dorsal motor nucleus of the vagus and were absent in the cuneate nucleus. These data suggest that brain stem nuclei, directly or indirectly related to respiratory control, share a common developmental trend with the pre-Bötzinger complex in having a transient period of imbalance between inhibitory and excitatory drives at P12. During this critical period, the respiratory system may be more vulnerable to excessive exogenous stressors.


1980 ◽  
Vol 238 (1) ◽  
pp. R57-R64 ◽  
Author(s):  
J. Ciriello ◽  
F. R. Calaresu

Experiments were done in cats anesthetized with chloralose, paralyzed and artificially ventilated cats to obtain electrophysiological evidence on the medullary site of origin of vagal cardioinhibitory fibers. The regions of the nucleus ambiguus (AMB), dorsal motor nucleus of the vagus (DMV), nucleus tractus solitarius (NTS), and external cuneate nucleus (ECN) were systematically explored for units responding both to antidromic stimulation of the cardiac branches of the vagus (CBV) and to orthodromic stimulation of the carotid sinus and aortic depressor nerves. Eighty-six single units conforming to these criteria were found in the medulla: 30 in the AMB, 26 in the DMV, 12 in the NTS, 8 in the NTS-DMV border region, and 10 in the ECN. Antidromically evoked spikes had durations of 0.5--2.5 ms and followed stimulation frequencies of 20--500 Hz. The axons of these units conducted at velocities of 3.3--20.8 m/s. The specificity of activation of medullary units by cardioinhibitory fibers was tested in 11 units, which were found to respond consistently with an antidromic spike to stimulation of CBV but not to stimulation of the thoracic vagus. In eight spinal animals low threshold (less than 15 microA) sites eliciting vagal bradycardia were found in the same medullary nuclei where cardioinhibitory units had been located. These results indicate that vagal cardioinhibitory axons, originate in at least three medullary nuclei, the AMB, DMV, and NTS. Unit activity from the ECN may have been recorded from carioinhibitory fibers because of the short duration of the spike potentials.


2004 ◽  
Vol 286 (4) ◽  
pp. R625-R633 ◽  
Author(s):  
Zixi (Jack) Cheng ◽  
Hong Zhang ◽  
Shang Z. Guo ◽  
Robert Wurster ◽  
David Gozal

In previous single-labeling experiments, we showed that neurons in the nucleus ambiguus (NA) and the dorsal motor nucleus of the vagus (DmnX) project to intrinsic cardiac ganglia. Neurons in these two motor nuclei differ significantly in the size of their projection fields, axon caliber, and endings in cardiac ganglia. These differences in NA and DmnX axon cardiac projections raise the question as to whether they target the same, distinct, or overlapping populations of cardiac principal neurons. To address this issue, we examined vagal terminals in cardiac ganglia and tracer injection sites in the brain stem using two different anterograde tracers {1,1′-dioleyl-3,3,3′,3′-tetramethylindocarbocyanine methanesulfonate and 4-[4-(dihexadecylamino)-styryl]- N-methylpyridinium iodide} and confocal microscopy in male Sprague-Dawley rats. We found that 1) NA and DmnX neurons innervate the same cardiac ganglia, but these axons target separate subpopulations of principal neurons and 2) axons arising from neurons in the NA and DmnX in the contralateral sides of the brain stem enter the cardiac ganglionic plexus through separate bundles and preferentially innervate principal neurons near their entry regions, providing topographic mapping of vagal motor neurons in left and right brain stem vagal nuclei. Because the NA and DmnX project to distinct populations of cardiac principal neurons, we propose that they may play different roles in controlling cardiac function.


1990 ◽  
Vol 258 (3) ◽  
pp. R788-R797 ◽  
Author(s):  
P. M. Gross ◽  
D. S. Wainman ◽  
S. W. Shaver ◽  
K. M. Wall ◽  
A. V. Ferguson

We used the quantitative [14C]deoxyglucose method and autoradiography to evaluate metabolic activity in 47 individual cerebral structures or subregions that are part of neural pathways emanating from the brain stem circumventricular organ, area postrema. Electrical stimulation of the dorsocentral area postrema in halothane-ventilated rats produced hypotension and increased glucose metabolism by several structures within the ascending trajectories of efferent neural projections from the nucleus. Structures in the caudal medulla oblongata, including three subnuclei of the nucleus of the solitary tract, dorsal motor nucleus of the vagus nerve, and nucleus ambiguus-A1 noradrenergic region, had increases of metabolism during stimulation of 32-62%. Pontine activation occurred specifically in the locus coeruleus and lateral parabrachial nuclei (increases of 24-36%). Magnocellular and parvocellular subdivisions of the hypothalamic paraventricular nucleus, supraoptic and suprachiasmatic nuclei, and median eminence showed increases in metabolism of 22-34%. An 89% elevation of glucose metabolism by the pituitary neural lobe resulted. The findings are evidence for functional activation of specific structures within ascending neural pathways from area postrema to forebrain mechanisms regulating blood pressure and fluid balance.


1987 ◽  
Vol 252 (2) ◽  
pp. H301-H306
Author(s):  
K. Shigematsu ◽  
M. Niwa ◽  
M. Kurihara ◽  
E. Castren ◽  
J. M. Saavedra

Substance P binding sites were characterized in brain nuclei of young (4-wk-old) and adult (16-wk-old) spontaneously hypertensive rats (SHR) and age-matched normotensive Wistar-Kyoto (WKY) control rats by quantitative autoradiography. Young SHR presented higher affinity constants (KA) than young WKY. The changes were restricted to the locus coeruleus, the area postrema, the dorsal motor nucleus of the vagus, and to discrete areas located in lobes 9 and 10 of the vermis cerebelli of SHR. There were no differences in the maximal binding capacity (Bmax) except in the nucleus ambiguus where the Bmax was lower than in WKY. Conversely, the number of substance P binding sites was higher in the locus coeruleus, the nucleus tegmentalis dorsalis, the nucleus ambiguus, the dorsal motor nucleus of the vagus, the hypoglossal nucleus, the inferior olivary nucleus, and lobes 9 and 10 of the vermis cerebelli of adult SHR when compared with adult WKY. Our results support the hypothesis of a role for brain substance P in blood pressure regulation and in genetic hypertension in rats.


1999 ◽  
Vol 79 (3) ◽  
pp. 855-916 ◽  
Author(s):  
Edwin W. Taylor ◽  
David Jordan ◽  
John H. Coote

This review explores the fundamental neuranatomical and functional bases for integration of the respiratory and cardiovascular systems in vertebrates and traces their evolution through the vertebrate groups, from primarily water-breathing fish and larval amphibians to facultative air-breathers such as lungfish and some adult amphibians and finally obligate air-breathers among the reptiles, birds, and mammals. A comparative account of respiratory rhythm generation leads to consideration of the changing roles in cardiorespiratory integration for central and peripheral chemoreceptors and mechanoreceptors and their central projections. We review evidence of a developing role in the control of cardiorespiratory interactions for the partial relocation from the dorsal motor nucleus of the vagus into the nucleus ambiguus of vagal preganglionic neurons, and in particular those innervating the heart, and for the existence of a functional topography of specific groups of sympathetic preganglionic neurons in the spinal cord. Finally, we consider the mechanisms generating temporal modulation of heart rate, vasomotor tone, and control of the airways in mammals; cardiorespiratory synchrony in fish; and integration of the cardiorespiratory system during intermittent breathing in amphibians, reptiles, and diving birds. Concluding comments suggest areas for further productive research.


1986 ◽  
Vol 250 (2) ◽  
pp. F189-F196 ◽  
Author(s):  
V. H. Gattone ◽  
C. F. Marfurt ◽  
S. Dallie

To determine the exact modalities involved in the innervation of the kidney, the present study used a nerve-tracing method with horseradish peroxidase-wheat germ agglutinin (HRP-WGA) as the tracer. Multiple injections of HRP-WGA were made in each of the left kidneys of 12 rats while another four had the HRP-WGA either dripped onto their intact renal mesothelial surface or injected intravascularly. After retrograde transport of the tracer to neurons of origin (i.e., 72-h survival), the rats were briefly perfusion fixed, tissue was removed, and cryostat sections were cut. The free-floating sections were reacted by the tetramethylbenzidine technique. Retrogradely labeled neurons were found in the celiac, bilateral inferior vagal (nodosal), and ipsilateral dorsal root (90% in T12-L1 DRG) ganglia. More labeled neurons were present in the combined vagal ganglia than in the combined DRG within each animal. This labeling was specific compared with the controls (HRP-WGA uptake via intraperitoneal or vascular routes). The celiac ganglion had many labeled neurons; however, no labeled neurons were seen in the dorsal motor nucleus of the vagus, nucleus solitarius, nucleus ambiguus, or any other brain stem structure after renal injections of HRP-WGA. This study has determined that the sympathetic nervous system (celiac ganglion) provides the only renal autonomic efferent (motor) innervation, and the nodosal (inferior vagal) ganglia appear to provide more renal sensory innervation than do the dorsal root ganglia.


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