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Brain and Behavior Nov 2018The arcuate nucleus is a component of the ventral medullary surface involved in chemoreception and breathing control. The hypoplasia of this nucleus is a very frequent...
INTRODUCTION
The arcuate nucleus is a component of the ventral medullary surface involved in chemoreception and breathing control. The hypoplasia of this nucleus is a very frequent finding in victims of sudden unexplained fetal and infant death (from the last weeks of pregnancy to the first year of life). On the contrary, this developmental alteration is rarely present in age-matched controls who died of defined causes. These observations lead to hypothesize that a well-developed and functional arcuate nucleus is generally required to sustain life. The aim of this study was to investigate whether the arcuate nucleus maintains the same supposed function throughout life.
METHODS
We carried out neuropathological examinations of brainstems obtained from 25 adult subjects, 18 males and 7 females, aged between 34 and 89 years, who died from various causes.
RESULTS
For almost half of the cases (44%) microscopic examinations of serial histological sections of medulla oblongata showed a normal cytoarchitecture of the arcuate nucleus, extending along the pyramids. For the remaining 56% of cases, various degrees of hypodevelopment of this nucleus were observed, validated through the application of quantitative morphometric investigations, from decreased area, neuron number and volume, to full aplasia.
CONCLUSIONS
These unexpected findings indicate that the involvement of the arcuate nucleus in chemoreception in adulthood is questionable, given the possibility of living until late age without this nucleus. This opens new perspectives for researchers on the role and function of the arcuate nucleus in humans from birth to old age.
Topics: Adult; Aged; Aged, 80 and over; Arcuate Nucleus of Hypothalamus; Brain Stem; Female; Humans; Male; Medulla Oblongata; Middle Aged; Neurons
PubMed: 30329220
DOI: 10.1002/brb3.1133 -
Brain : a Journal of Neurology Jun 2018Sudden unexpected death in epilepsy (SUDEP) is a leading cause of premature death in patients with epilepsy. One hypothesis proposes that sudden death is mediated by...
Sudden unexpected death in epilepsy (SUDEP) is a leading cause of premature death in patients with epilepsy. One hypothesis proposes that sudden death is mediated by post-ictal central respiratory depression, which could relate to underlying pathology in key respiratory nuclei and/or their neuromodulators. Our aim was to investigate neuronal populations in the ventrolateral medulla (which includes the putative human pre-Bötzinger complex) and the medullary raphe. Forty brainstems were studied comprising four groups: 14 SUDEP, six epilepsy controls, seven Dravet syndrome cases and 13 non-epilepsy controls. Serial sections through the medulla (from obex 1 to 10 mm) were stained for Nissl, somatostatin, neurokinin 1 receptor (for pre-Bötzinger complex neurons) and galanin, tryptophan hydroxylase and serotonin transporter (neuromodulatory systems). Using stereology total neuronal number and densities, with respect to obex level, were measured. Whole slide scanning image analysis was used to quantify immunolabelling indices as well as co-localization between markers. Significant findings included reduction in somatostatin neurons and neurokinin 1 receptor labelling in the ventrolateral medulla in sudden death in epilepsy compared to controls (P < 0.05). Galanin and tryptophan hydroxylase labelling was also reduced in sudden death cases and more significantly in the ventrolateral medulla region than the raphe (P < 0.005 and P < 0.05). With serotonin transporter, reduction in labelling in cases of sudden death in epilepsy was noted only in the raphe (P ≤ 0.01); however, co-localization with tryptophan hydroxylase was significantly reduced in the ventrolateral medulla. Epilepsy controls and cases with Dravet syndrome showed less significant alterations with differences from non-epilepsy controls noted only for somatostatin in the ventrolateral medulla (P < 0.05). Variations in labelling with respect to obex level were noted of potential relevance to the rostro-caudal organization of respiratory nuclear groups, including tryptophan hydroxylase, where the greatest statistical difference noted between all epilepsy cases and controls was at obex 9-10 mm (P = 0.034), the putative level of the pre-Bötzinger complex. Furthermore, there was evidence for variation with duration of epilepsy for somatostatin and neurokinin 1 receptor. Our findings suggest alteration to neuronal populations in the medulla in SUDEP with evidence for greater reduction in neuromodulatory neuropeptidergic and mono-aminergic systems, including for galanin, and serotonin. Other nuclei need to be investigated to evaluate if this is part of more widespread brainstem pathology. Our findings could be a result of previous seizures and may represent a pathological risk factor for SUDEP through impaired respiratory homeostasis during a seizure.
Topics: Adolescent; Adult; Autopsy; Death, Sudden; Epilepsy; Female; Humans; Magnetic Resonance Imaging; Male; Medulla Oblongata; Membrane Proteins; Middle Aged; Nerve Tissue Proteins; Raphe Nuclei; Retrospective Studies; Severity of Illness Index; Young Adult
PubMed: 29608654
DOI: 10.1093/brain/awy078 -
Annals of Palliative Medicine Feb 2021Medulla oblongata myelinolysis is an extremely rare manifestation of extrapontine myelinolysis (EPM). Herein, we report a case of a 34-year-old man with a history of...
Medulla oblongata myelinolysis is an extremely rare manifestation of extrapontine myelinolysis (EPM). Herein, we report a case of a 34-year-old man with a history of gout who presented repeated vomiting and diarrhea after ingesting 15 colchicine pills. A hyponatremia diagnosis was given and after an intensive treatment, his serum sodium level increased from 118 to 129 mmol/L within 24 hours. Brain magnetic resonance imaging (MRI) revealed a lesion in the medulla oblongata that appeared as a hypointense area in T1-weighted images and a hyperintense area in T2-weighted images. A diagnosis of medulla oblongata myelinolysis and colchicine poisoning was then given, and methylprednisolone therapy was initiated. Seventeen days later, the patient achieved a good outcome with methylprednisolone therapy. However, his medulla oblongata lesion remained detectable with MRI. Medulla oblongata myelinolysis is an extremely rare manifestation of EPM, and unique for being colchicine-induced. This case shows that colchicine poisoning can lead to hyponatremia, which in turn can induce myelinolysis if not treated correctly. As exemplified by our patient's case, desirable treatment outcomes are possible in such cases, although these outcomes may not be associated with a visible reduction of the brain lesions in MRI scans.
Topics: Adult; Colchicine; Humans; Hyponatremia; Magnetic Resonance Imaging; Male; Medulla Oblongata; Myelinolysis, Central Pontine
PubMed: 32527125
DOI: 10.21037/apm-19-627 -
Nan Fang Yi Ke Da Xue Xue Bao = Journal... May 2024To assess the effects of repeated mild traumatic brain injury (rmTBI) in the parietal cortex on neuronal morphology and synaptic plasticity in the medulla oblongata of...
OBJECTIVE
To assess the effects of repeated mild traumatic brain injury (rmTBI) in the parietal cortex on neuronal morphology and synaptic plasticity in the medulla oblongata of mice.
METHODS
Thirty-two male ICR mice were randomly divided into sham operation group (=8) and rmTBI group (=24). The mice in the latter group were subjected to repeated mild impact injury of the parietal cortex by a free-falling object. The mice surviving the injuries were evaluated for neurological deficits using neurological severity scores (NSS), righting reflex test and forced swimming test, and pathological changes of the neuronal cells in the medulla oblongata were observed with HE and Nissl staining. Western blotting and immunofluorescence staining were used to detect the expressions of neuroligin 1(NLG-1) and postsynaptic density protein 95(PSD-95) in the medulla oblongata of the mice that either survived rmTBI or not.
RESULTS
None of the mice in the sham-operated group died, while the mortality rate was 41.67% in rmTBI group. The mice surviving rmTBI showed significantly reduced NSS, delayed recovery of righting reflex, increased immobility time in forced swimming test ( < 0.05), and loss of Nissl bodies; swelling and necrosis were observed in a large number of neurons in the medulla oblongata, where the expression levels of NLG-1 and PSD-95 were significantly downregulated ( < 0.05). The mice that did not survive rmTBI showed distorted and swelling nerve fibers and decreased density of neurons in the medulla oblongina with lowered expression levels of NLG-1 and PSD-95 compared with the mice surviving the injuries ( < 0.01).
CONCLUSION
The structural and functional anomalies of the synapses in the medulla oblongata may contribute to death and neurological impairment following rmTBI in mice.
Topics: Animals; Mice; Medulla Oblongata; Disks Large Homolog 4 Protein; Male; Mice, Inbred ICR; Parietal Lobe; Cell Adhesion Molecules, Neuronal; Neurons; Brain Injuries, Traumatic; Neuronal Plasticity
PubMed: 38862454
DOI: 10.12122/j.issn.1673-4254.2024.05.18 -
BMJ Case Reports Mar 2021Symptomatic brainstem compression from vertebral artery dolichoectasia is rare. There are no recognised diagnostic or treatment criteria to guide management of this... (Review)
Review
Symptomatic brainstem compression from vertebral artery dolichoectasia is rare. There are no recognised diagnostic or treatment criteria to guide management of this disease. We report a case of medullary compression and cerebral ischaemia from an enlarged and tortuous vertebral artery. Our patient developed progressive dysphonia and dysphagia. Cerebral MRI revealed compression of the medulla oblongata by a right ectatic vertebral artery and a right occipital lobe infarct. Other causes of bulbar dysfunction were ruled out. He was treated with anticoagulation and underwent percutaneous endoscopic gastrostomy. We review selected literature on the presentation, diagnosis and management of this rare neurologic condition.
Topics: Aged, 80 and over; Brain Diseases; Humans; Magnetic Resonance Imaging; Male; Medulla Oblongata; Vertebral Artery
PubMed: 33722909
DOI: 10.1136/bcr-2020-238323 -
Journal of Veterinary Internal Medicine Nov 2017Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates...
BACKGROUND
Chiari-like malformation (CM) and syringomyelia (SM) are widely reported in Cavalier King Charles Spaniels and Griffon Bruxellois dogs. Increasing evidence indicates that CM and SM also occur in other small and toy breed dogs, such as Chihuahuas.
OBJECTIVES
To describe the presence of SM and craniocervical junction (CCJ) abnormalities in Chihuahuas and to evaluate the possible association of CCJ abnormalities with SM. To describe CM/SM-related clinical signs and neurologic deficits and to investigate the association of CM/SM-related clinical signs with signalment, SM, or CCJ abnormalities.
ANIMALS
Fifty-three client-owned Chihuahuas.
METHODS
Prospective study. Questionnaire analyses and physical and neurologic examinations were obtained before magnetic resonance and computed tomography imaging. Images were evaluated for the presence of SM, CM, and atlantooccipital overlapping. Additionally, medullary kinking, dorsal spinal cord compression, and their sum indices were calculated.
RESULTS
Scratching was the most common CM/SM-related clinical sign and decreased postural reaction the most common neurologic deficit in 73 and 87% of dogs, respectively. Chiari-like malformation and SM were present in 100 and 38% of dogs, respectively. Syringomyelia was associated with the presence of CM/SM-related clinical signs (P = 0.034), and medullary kinking and sum indices were higher in dogs with clinical signs (P = 0.016 and P = 0.007, respectively).
CONCLUSIONS AND CLINICAL IMPORTANCE
Syringomyelia and CCJ abnormalities are prevalent in Chihuahuas. Syringomyelia was an important factor for the presence of CM/SM-related clinical signs, but many dogs suffered from similar clinical signs without being affected by SM, highlighting the clinical importance of CCJ abnormalities in Chihuahuas.
Topics: Animals; Arnold-Chiari Malformation; Atlanto-Occipital Joint; Dog Diseases; Dogs; Female; Magnetic Resonance Imaging; Male; Medulla Oblongata; Prospective Studies; Species Specificity; Spinal Cord Compression; Syringomyelia; Tomography, X-Ray Computed
PubMed: 28892202
DOI: 10.1111/jvim.14826 -
AJNR. American Journal of Neuroradiology Aug 2014Disturbed somatosensory evoked potentials have been demonstrated in patients with adolescent idiopathic scoliosis (but this functional delay was found to originate above...
Variation in anisotropy and diffusivity along the medulla oblongata and the whole spinal cord in adolescent idiopathic scoliosis: a pilot study using diffusion tensor imaging.
BACKGROUND AND PURPOSE
Disturbed somatosensory evoked potentials have been demonstrated in patients with adolescent idiopathic scoliosis (but this functional delay was found to originate above the C5-6 level, while the lower cord level was unaffected). Together with MR imaging observation of tonsillar ectopia and a relatively tethered cord, we hypothesized that there is disturbed mean diffusivity integrity along the spinal cord. In this study, advanced DTI was used to evaluate whether there was underlying decreased WM integrity within the brain stem and spinal cord in adolescent idiopathic scoliosis and any relationship to cerebellar tonsillar ectopia. Clinical impact on balance testing was also correlated.
MATERIALS AND METHODS
Thirteen girls with adolescent idiopathic scoliosis with right thoracic curves were compared with 13 age-matched healthy girls. DTI of the brain and whole spinal cord was performed. ROIs were manually defined for the medulla oblongata and along each intervertebral segment of the cord. Mean values of fractional anisotropy and mean diffusivity were computed at the defined regions. Between-group comparisons were performed by 1-way ANOVA.
RESULTS
Significantly decreased fractional anisotropy values and increased mean diffusivity values were found at the medulla oblongata and C1-2, C2-3, C3-4, and C4-5 segments in patients with adolescent idiopathic scoliosis compared with healthy subjects. No significant difference was found in the lower cord levels. Significant correlation was found between the tonsillar level and fractional anisotropy value at the C4-5 level in patients with adolescent idiopathic scoliosis only.
CONCLUSIONS
The findings from this study are in agreement with previous findings showing abnormal somatosensory evoked potential readings occurring only above the C5-6 level in patients with adolescent idiopathic scoliosis; these findings might partially explain the pathophysiology of the neural pathway involved.
Topics: Adolescent; Anisotropy; Diffusion Tensor Imaging; Evoked Potentials, Somatosensory; Female; Humans; Medulla Oblongata; Pilot Projects; Scoliosis; Spinal Cord
PubMed: 24788126
DOI: 10.3174/ajnr.A3912 -
Journal of Neurophysiology Apr 2021The incidence of Parkinson's disease (PD) is increasing worldwide. Although the PD hallmark is the motor impairments, nonmotor dysfunctions are now becoming more... (Review)
Review
The incidence of Parkinson's disease (PD) is increasing worldwide. Although the PD hallmark is the motor impairments, nonmotor dysfunctions are now becoming more recognized. Recently, studies have suggested that baroreflex dysfunction is one of the underlying mechanisms of cardiovascular dysregulation observed in patients with PD. However, the large body of literature on baroreflex function in PD is unclear. The baroreflex system plays a major role in the autonomic, and ultimately blood pressure and heart rate, adjustments that accompany acute cardiovascular stressors on a daily basis. Therefore, impaired baroreflex function (i.e., decreased sensitivity or gain) can lead to altered neural cardiovascular responses. Since PD affects parasympathetic and sympathetic branches of the autonomic nervous system and both are orchestrated by the baroreflex system, understanding of this crucial mechanism in PD is necessary. In the present review, we summarize the potential altered central and peripheral mechanisms affecting the feedback-controlled loops that comprise the reflex arc in patients with PD. Major factors including arterial stiffness, reduced number of C1 and activation of non-C1 neurons, presence of central α-synuclein aggregation, cardiac sympathetic denervation, attenuated muscle sympathetic nerve activity, and lower norepinephrine release could compromise baroreflex function in PD. Results from patients with PD and from animal models of PD provide the reader with a clearer picture of baroreflex function in this clinical condition. By doing so, our intent is to stimulate future studies to evaluate several unanswered questions in this research area.
Topics: Animals; Baroreflex; Blood Pressure; Humans; Medulla Oblongata; Parkinson Disease; Sympathetic Nervous System
PubMed: 33625931
DOI: 10.1152/jn.00548.2020 -
The Journal of Comparative Neurology Sep 2018Astrocytes, the most abundant and structurally complex glial cells of the central nervous system, are proposed to play an important role in modulating the activities of...
Astrocytes, the most abundant and structurally complex glial cells of the central nervous system, are proposed to play an important role in modulating the activities of neuronal networks, including respiratory rhythm-generating circuits of the preBötzinger complex (preBötC) located in the ventrolateral medulla of the brainstem. However, structural properties of astrocytes residing within different brainstem regions are unknown. In this study astrocytes in the preBötC, an intermediate reticular formation (IRF) region with respiratory-related function, and a region of the nucleus tractus solitarius (NTS) in adult rats were reconstructed and their morphological features were compared. Detailed morphological analysis revealed that preBötC astrocytes are structurally more complex than those residing within the functionally distinct neighboring IRF region, or the NTS, located at the dorsal aspect of the medulla oblongata. Structural analyses of the brainstem microvasculature indicated no significant regional differences in vascular properties. We hypothesize that high morphological complexity of preBötC astrocytes reflects their functional role in providing structural/metabolic support and modulation of the key neuronal circuits essential for breathing, as well as constraints imposed by arrangements of associated neurons and/or other local structural features of the brainstem parenchyma.
Topics: Animals; Astrocytes; Brain Stem; Capillaries; Male; Medulla Oblongata; Rats; Rats, Sprague-Dawley; Respiration; Respiratory Physiological Phenomena; Reticular Formation; Solitary Nucleus
PubMed: 29888789
DOI: 10.1002/cne.24472 -
Physiological Research Dec 2017Neuronal activity in the medulla oblongata and neurogenic inflammation of airways were investigated in a guinea pig model induced by repeated intra-esophageal...
Vagotomy decreases the neuronal activities of medulla oblongata and alleviates neurogenic inflammation of airways induced by repeated intra-esophageal instillation of HCl in guinea pigs.
Neuronal activity in the medulla oblongata and neurogenic inflammation of airways were investigated in a guinea pig model induced by repeated intra-esophageal instillation of hydrochloric acid (HCl) after vagotomy. Unilateral vagotomy was performed in the vagotomy group, while a sham-operation was performed in the sham group. Operation was not conducted in sham control group. Airway inflammation was observed with hematoxylin and eosin (HE) staining. C-fos protein was measured by immunohistochemistry (IHC) and Western blot (WB). Substance P was examined by IHC and enzyme-linked immuno sorbent assay (ELISA). Airway microvascular permeability was detected by evans blue dye (EBD) fluorescence. Inflammation of airway was observed in the trachea and bronchi after chronic HCl perfusion into the lower esophagus, and was alleviated after unilateral vagotomy. C-fos expression in the medulla oblongata was lower in the vagotomy group compared to the sham control and sham groups. Substance P-like immunoreactivity (SP-li), concentration and microvascular leakage in airway were lower in the vagotomy group than that in the other groups. Our results suggest that vagotomy improved neurogenic inflammation of airways and decreased neuronal activities, the afferent nerves and neurons in medulla oblongata may be involved in neurogenic inflammation of airways mediated by esophageal-bronchial reflex.
Topics: Animals; Capillary Permeability; Esophagus; Guinea Pigs; Hydrochloric Acid; Lung; Male; Medulla Oblongata; Neurogenic Inflammation; Pneumonia, Aspiration; Proto-Oncogene Proteins c-fos; Reflex, Abnormal; Substance P; Vagotomy
PubMed: 28937249
DOI: 10.33549/physiolres.933574