scholarly journals 3D Reconstruction of the Morpho-Functional Topography of the Human Vagal Trigone

2021 ◽  
Vol 15 ◽  
Author(s):  
Aron Emmi ◽  
Andrea Porzionato ◽  
Martina Contran ◽  
Enrico De Rose ◽  
Veronica Macchi ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Fourth Ventricle ◽  
Morphological Characterization ◽  
Motor Nucleus ◽  
Neurosurgical Procedures ◽  
Solitary Tract Nucleus ◽  
Microscopical Examination ◽  
Solitary Tract ◽  
Dorsal Motor Nucleus ◽  
Axial Profile

The Vagal Trigone, often referred to as Ala Cinerea, is a triangular-shaped area of the floor of the fourth ventricle that is strictly involved in the network of chardiochronotropic, baroceptive, respiratory, and gastrointestinal control systems of the medulla oblongata. While it is frequently identified as the superficial landmark for the underlying Dorsal Motor Nucleus of the Vagus, this correspondence is not univocal in anatomical literature and is often oversimplified in neuroanatomy textbooks and neurosurgical atlases. As the structure represents an important landmark for neurosurgical procedures involving the floor of the fourth ventricle, accurate morphological characterization is required to avoid unwanted side effects (e.g., bradychardia, hypertension) during neuorphysiological monitoring and cranial nerve nuclei stimulation in intraoperative settings. The aim of this study was to address the anatomo-topographical relationships of the Vagal Trigone with the underlying nuclei. For this purpose, we have conducted an anatomo-microscopical examination of serial sections deriving from 54 Human Brainstems followed by 3D reconstruction and rendering of the specimens. Our findings indicate that the Vagal Trigone corresponds only partially with the Dorsal Motor Nucleus of the Vagus, while most of its axial profile is occupied by the dorsal regions of the Solitary Tract Nucleus. Furthermore, basing on literature and our findings we speculate that the neuroblasts of the Dorsal Motor Nucleus of the Vagus undergo neurobiotaxic migration induced by the neuroblasts of the dorsolaterally located solitary tract nucleus, giving rise to the Ala Cinerea, a topographically defined area for parasympathetic visceral control.

scholarly journals The Neural Pathway of Reflex Regulation of Electroacupuncture at Orofacial Acupoints on Gastric Functions in Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Jianhua Liu ◽  
Wenbin Fu ◽  
Wei Yi ◽  
Zhenhua Xu ◽  
Nenggui Xu
Keyword(s):  
Myoelectric Activity ◽  
Motor Nucleus ◽  
Dorsal Vagal Complex ◽  
Solitary Tract ◽  
Neural Pathway ◽  
Excitatory Effect ◽  
Reflex Regulation ◽  
Gastric Myoelectric Activity ◽  
Dorsal Motor Nucleus ◽  
Spike Bursts

Acupuncture has a reflex regulation in gastrointestinal functions, which is characterized with segment. In the present study, the neural pathway of electroacupuncture (EA) at orofacial acupoints (ST2) on gastric myoelectric activity (GMA) in rats was investigated. The results indicated that EA at ST2 facilitated spike bursts of GMA, which is similar to EA at limbs and opposite to EA at abdomen. The excitatory effect was abolished by the transaction of infraorbital nerves, dorsal vagal complex lesion, and vagotomy, respectively. In addition, microinjection of L-glutamate into the nucleus of the solitary tract (NTS) attenuated the excitatory effect. All these data suggest that the dorsal vagal complex is involved in the reflex regulation of EA at orofacial acupoints on gastric functions and NTS-dorsal motor nucleus of the vagus (DMV) inhibitory connections may be essential for it.

Galanin Inhibits Gut-Related Vagal Neurons in Rats

2004 ◽  
Vol 91 (5) ◽  
pp. 2330-2343 ◽  
Author(s):  
Zhenjun Tan ◽  
Ronald Fogel ◽  
Chunhui Jiang ◽  
Xueguo Zhang
Keyword(s):  
Potassium Channel ◽  
Reversal Potential ◽  
Outward Current ◽  
Motor Nucleus ◽  
Dorsal Vagal Complex ◽  
Solitary Tract ◽  
Membrane Hyperpolarization ◽  
Dorsal Motor Nucleus

Galanin plays an important role in the regulation of food intake, energy balance, and body weight. Many galanin-positive fibers as well as galanin-positive neurons were seen in the dorsal vagal complex, suggesting that galanin produces its effects by actions involving vagal neurons. In the present experiment, we used tract-tracing and neurophysiological techniques to evaluate the origin of the galaninergic fibers and the effect of galanin on neurons in the dorsal vagal complex. Our results reveal that the nucleus of the solitary tract is the major source of the galanin terminals in the dorsal vagal complex. In vivo experiments demonstrated that galanin inhibited the majority of gut-related neurons in the dorsal motor nucleus of the vagus. In vitro experiments demonstrated that galanin inhibited the majority of stomach-projecting neurons in the dorsal motor nucleus of the vagus by suppressing spontaneous activity and/or producing a fully reversible dose-dependent membrane hyperpolarization and outward current. The galanin-induced hyperpolarization and outward current persisted after synaptic input was blocked, suggesting that galanin acts directly on receptors of neurons in the dorsal motor nucleus of the vagus. The reversal potential induced by galanin was close to the potassium ion potentials of the Nernst equation and was prevented by the potassium channel blocker tetraethylammonium, indicating that the inhibitory effect of galanin was mediated by a potassium channel. These results indicate that the dorsal motor nucleus of the vagus is inhibited by galanin derived predominantly from neurons in the nucleus of the solitary tract projecting to the dorsal motor nucleus of the vagus nerve. Galanin is one of the neurotransmitters involved in the vago-vagal reflex.

Distribution of α2-Adrenergic Receptor Binding in the Developing Human Brain Stem

2001 ◽  
Vol 4 (3) ◽  
pp. 222-236 ◽  
Author(s):  
Jaleh Mansouri ◽  
Ashok Panigrahy ◽  
Susan F. Assmann ◽  
Hannah C. Kinney
Keyword(s):  
Brain Stem ◽  
Reticular Formation ◽  
Inferior Olive ◽  
Human Life ◽  
Motor Nucleus ◽  
Solitary Tract ◽  
Medullary Reticular Formation ◽  
Cardiorespiratory Control ◽  
Dorsal Motor Nucleus ◽  
Early Human

Rapid and dramatic changes occur in cardiorespiratory function during early human life. Catecholamines within select brain stem nuclei are implicated in the control of autonomic and respiratory function, including in the nucleus of the solitary tract and the dorsal motor nucleus of X. Animal and adult human studies have shown high binding to α2-adrenergic receptors in these regions. To determine the developmental profile of brainstem α2-adrenergic binding across early human life, we studied brain stems from five fetuses at mid-gestation, three newborns (37–38 postconceptional weeks), and six infants (44–61 postconceptional weeks). We used quantitative tissue receptor autoradiography with [3H]para-aminoclonidine as the radioligand and phentolamine as the displacer. In the fetal group, binding was high (63–93 fmol/mg tissue) in the nucleus of the solitary tract, dorsal motor nucleus of X, locus coeruleus, and reticular formation; it was low (<32 fmol/mg tissue) in the principal inferior olive and basis pontis. Binding decreased in all regions with age: in infancy, the highest binding was in the intermediate range (32–62 fmol/mg tissue) and was localized to the nucleus of the solitary tract and dorsal motor nucleus of X. The most substantial decrease in binding (75%–85%) between the fetal and infant periods occurred in the pontine and medullary reticular formation and hypoglossal nucleus. Binding remained low in the principal inferior olive and basis pontis. The decreases in binding with age remained significant after quench correction. These data suggest that rapid and dramatic changes occur in early human life in the brain stem catecholaminergic system in regions related to cardiorespiratory control.

Mechanisms of angiotensin-induced hypotension and bradycardia in the medial solitary tract nucleus

1994 ◽  
Vol 267 (1) ◽  
pp. H259-H266 ◽  
Author(s):  
J. E. Fow ◽  
D. B. Averill ◽  
K. L. Barnes
Keyword(s):  
Cardiovascular Effects ◽  
Receptor Subtype ◽  
Motor Nucleus ◽  
Ang Ii ◽  
Solitary Tract ◽  
Induced Hypotension ◽  
Medial Nucleus ◽  
Dorsal Motor Nucleus ◽  
At1 Antagonist ◽  
Dose Dependent

The selective angiotensin (ANG) II antagonists losartan (AT1) and CGP-42112A (AT2) were used to determine the receptor subtype and neuronal pathways that mediate the hypotension and bradycardia produced by 200 fmol of ANG II microinjected into the dorsal medial nucleus tractus solitarii (NTS) or dorsal motor nucleus of the vagus (dmnX) in anesthetized rats. At dorsal medial NTS sites (0.3 mm below the surface) where L-glutamate microinjections produced maximal decreases in mean arterial pressure (MAP) and heart rate (HR), ANG II (200 fmol, 50 nl, n = 16) elicited hypotension (-22 +/- 1 mmHg) and bradycardia (-26 +/- 2 beats/min). Although L-glutamate also suppressed respiration, ANG II injections in the medial NTS did not alter respiration. Losartan injected at the medial NTS site caused a dose-dependent reduction of ANG II-induced decreases in MAP and HR. At 2 pmol, the AT1 antagonist attenuated the response to ANG II, whereas 100 pmol abolished the effects of ANG II microinjections. In contrast, the AT2 antagonist CGP-42112A (100 pmol) had no effect on the responses to ANG II. Neither ANG II antagonist altered the cardiovascular effects of L-glutamate injections. Losartan injected into the dmnX blocked hypotension and bradycardia produced by ANG II at that site but did not prevent responses to subsequent ANG II injections in the medial NTS.(ABSTRACT TRUNCATED AT 250 WORDS)

Sign in / Sign up

Export Citation Format

Share Document