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Edwards MM, Nguyen HK, Herbertson AJ, Dodson AD, Wietecha T, Wolden-Hanson T, Graham JL, O'Brien KD, Havel PJ, Blevins JE. Chronic hindbrain administration of oxytocin elicits weight loss in male diet-induced obese mice. Am J Physiol Regul Integr Comp Physiol 2021; 320:R471-R487. [PMID: 33470901 PMCID: PMC8238148 DOI: 10.1152/ajpregu.00294.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/15/2021] [Accepted: 01/16/2021] [Indexed: 02/08/2023]
Abstract
Previous studies indicate that oxytocin (OT) administration reduces body weight in high-fat diet (HFD)-induced obese (DIO) rodents through both reductions in food intake and increases in energy expenditure. We recently demonstrated that chronic hindbrain [fourth ventricular (4V)] infusions of OT evoke weight loss in DIO rats. Based on these findings, we hypothesized that chronic 4V OT would elicit weight loss in DIO mice. We assessed the effects of 4V infusions of OT (16 nmol/day) or vehicle over 28 days on body weight, food intake, and body composition. OT reduced body weight by approximately 4.5% ± 1.4% in DIO mice relative to OT pretreatment body weight (P < 0.05). These effects were associated with reduced adiposity and adipocyte size [inguinal white adipose tissue (IWAT)] (P < 0.05) and attributed, in part, to reduced energy intake (P < 0.05) at a dose that did not increase kaolin intake (P = NS). OT tended to increase uncoupling protein-1 expression in IWAT (0.05 < P < 0.1) suggesting that OT stimulates browning of WAT. To assess OT-elicited changes in brown adipose tissue (BAT) thermogenesis, we examined the effects of 4V OT on interscapular BAT temperature (TIBAT). 4V OT (1 µg) elevated TIBAT at 0.75 (P = 0.08), 1, and 1.25 h (P < 0.05) postinjection; a higher dose (5 µg) elevated TIBAT at 0.75-, 1-, 1.25-, 1.5-, 1.75- (P < 0.05), and 2-h (0.05 < P < 0.1) postinjection. Together, these findings support the hypothesis that chronic hindbrain OT treatment evokes sustained weight loss in DIO mice by reducing energy intake and increasing BAT thermogenesis at a dose that is not associated with evidence of visceral illness.
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MESH Headings
- Adipocytes, Brown/drug effects
- Adipocytes, Brown/metabolism
- Adipocytes, Brown/pathology
- Adipocytes, White/drug effects
- Adipocytes, White/metabolism
- Adipocytes, White/pathology
- Adiposity/drug effects
- Animals
- Anti-Obesity Agents/administration & dosage
- Diet, High-Fat
- Disease Models, Animal
- Eating/drug effects
- Energy Intake/drug effects
- Infusions, Intraventricular
- Leptin/blood
- Male
- Mice, Inbred C57BL
- Obesity/drug therapy
- Obesity/metabolism
- Obesity/pathology
- Obesity/physiopathology
- Oxytocin/administration & dosage
- Rhombencephalon/drug effects
- Rhombencephalon/physiopathology
- Thermogenesis/drug effects
- Uncoupling Protein 1/metabolism
- Weight Loss/drug effects
- Mice
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Affiliation(s)
- Melise M Edwards
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Ha K Nguyen
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Adam J Herbertson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Andrew D Dodson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - Tomasz Wietecha
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
| | - Tami Wolden-Hanson
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
| | - James L Graham
- Department of Nutrition, University of California, Davis, California
| | - Kevin D O'Brien
- UW Medicine Diabetes Institute, University of Washington School of Medicine, Seattle, Washington
- Division of Cardiology, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
| | - Peter J Havel
- Department of Nutrition, University of California, Davis, California
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, California
| | - James E Blevins
- Office of Research and Development Medical Research Service, Department of Veterans Affairs Medical Center, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, Washington
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2
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Barker MS, Knight JL, Dean RJ, Mandelstam S, Richards LJ, Robinson GA. Verbal Adynamia and Conceptualization in Partial Rhombencephalosynapsis and Corpus Callosum Dysgenesis. Cogn Behav Neurol 2021; 34:38-52. [PMID: 33652468 DOI: 10.1097/wnn.0000000000000261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 07/02/2020] [Indexed: 11/26/2022]
Abstract
Verbal adynamia is characterized by markedly reduced spontaneous speech that is not attributable to a core language deficit such as impaired naming, reading, repetition, or comprehension. In some cases, verbal adynamia is severe enough to be considered dynamic aphasia. We report the case of a 40-year-old, left-handed, male native English speaker who presented with partial rhombencephalosynapsis, corpus callosum dysgenesis, and a language profile that is consistent with verbal adynamia, or subclinical dynamic aphasia, possibly underpinned by difficulties selecting and generating ideas for expression. This case is only the second investigation of dynamic aphasia in an individual with a congenital brain malformation. It is also the first detailed neuropsychological report of an adult with partial rhombencephalosynapsis and corpus callosum dysgenesis, and the only known case of superior intellectual abilities in this context.
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Affiliation(s)
- Megan S Barker
- Neuropsychology Research Unit, School of Psychology, The University of Queensland, St Lucia, Brisbane, Australia
- Taub Institute, Columbia University Medical Center, New York, New York
| | - Jacquelyn L Knight
- Neuropsychology Research Unit, School of Psychology, The University of Queensland, St Lucia, Brisbane, Australia
| | - Ryan J Dean
- Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, Australia
| | - Simone Mandelstam
- Department of Radiology, University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia
- Department of Paediatrics, University of Melbourne, Parkville, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia
| | - Linda J Richards
- Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, Australia
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Brisbane, Australia
| | - Gail A Robinson
- Neuropsychology Research Unit, School of Psychology, The University of Queensland, St Lucia, Brisbane, Australia
- Queensland Brain Institute, The University of Queensland, St Lucia, Brisbane, Australia
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3
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Gupta RG, Schafer C, Ramaroson Y, Sciullo MG, Horn CC. Role of the abdominal vagus and hindbrain in inhalational anesthesia-induced vomiting. Auton Neurosci 2016; 202:114-121. [PMID: 27396693 DOI: 10.1016/j.autneu.2016.06.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 12/28/2022]
Abstract
The incidence of postoperative nausea and vomiting (PONV) can be as high as 80% in patients with risk factors (e.g., females, history of motion sickness). PONV delays postoperative recovery and costs several hundred million dollars annually. Cell-based assays show that halogenated ethers (e.g., isoflurane) activate 5-HT3 receptors, which are found on gastrointestinal vagal afferents and in the hindbrain - key pathways for producing nausea and vomiting. This project evaluated the role of the vagus and activation of the hindbrain in isoflurane-induced emesis in musk shrews, a small animal model with a vomiting reflex, which is lacking in rats and mice. Sham-operated and abdominal vagotomized shrews were exposed to 1 to 3% isoflurane to determine effects on emesis; vagotomy was confirmed by lack of vagal transport of the neuronal tracer Fluoro-Gold. In an additional study, shrews were exposed to isoflurane and hindbrain c-Fos was measured at 90min after exposure using immunohistochemistry. There were no statistically significant effects of vagotomy on isoflurane-induced emesis compared to sham-operated controls. Isoflurane exposure produced a significant increase in c-Fos-positive cells in the nucleus of the solitary tract and vestibular nuclei but not in the area postrema or dorsal motor nucleus. These results indicate that the abdominal vagus plays no role in isoflurane-induced emesis and suggest that isoflurane activates emesis by action on the hindbrain, as shown by c-Fos labeling. Ultimately, knowledge of the mechanisms of inhalational anesthesia-induced PONV could lead to more targeted therapies to control PONV.
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Affiliation(s)
- Ragini G Gupta
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Claire Schafer
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Michael G Sciullo
- Biobehavioral Oncology Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - Charles C Horn
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Biobehavioral Oncology Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; Department of Anesthesiology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Medicine, Division of Gastroenterology, Hepatology, and Nutrition, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States.
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4
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Tainta M, de la Riva P, Gonzalez F, Marti-Masso JF, Goenaga MA. [Rhomboencephalitis and endocarditis caused by Listeria monocytogenes: an unreported association]. Rev Neurol 2016; 63:46-48. [PMID: 27345281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- M Tainta
- Hospital Donostia, 20014 San Sebastian, Espana
| | | | - F Gonzalez
- Hospital Donostia, 20014 San Sebastian, Espana
| | - J F Marti-Masso
- Hospital Donostia, 20014 San Sebastian, Espana
- Universidad del Pais Vasco, Donostia-San Sebastian, Espana
- Instituto Biodonostia, San Sebastian, Espana
| | - M A Goenaga
- Hospital Donostia, 20014 San Sebastian, Espana
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5
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Balaban O, Tobias JD. PERIOPERATIVE CARE OF AN INFANT WITH GOMEZ-LOPEZ-HERNANDEZ SYNDROME. Middle East J Anaesthesiol 2016; 23:581-585. [PMID: 27487646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Gomez-Lopez-Hernandez syndrome, also known as cerebello-trigeminal dermal dysplasia, is a rare neurocutaneous syndrome classically characterized by the triad of rhombencephalosynapsis, trigeminal anesthesia, and bilateral parietal alopecia. Associated clinical features include a characteristic facial appearance (mid-face hypoplasia, hypertelorism, and low-set, posteriorly rotated ears), brachycephaly, strabismus, ataxia, developmental delay, short stature, and corneal opacities. Given the associated congenital anomalies, anesthetic care may be required for various surgical interventions. We report a 7-month-old with Gomez-Lopez-Hernandez syndrome scheduled for laparoscopic gastrostomy with tube placement and frenulotomy under general anesthesia. The potential perioperative implications of such patients are reviewed and options for anesthetic care discussed.
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6
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Minkel HR, Anwer TZ, Arps KM, Brenner M, Olsen ML. Elevated GFAP induces astrocyte dysfunction in caudal brain regions: A potential mechanism for hindbrain involved symptoms in type II Alexander disease. Glia 2015; 63:2285-97. [PMID: 26190408 PMCID: PMC4555878 DOI: 10.1002/glia.22893] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 07/01/2015] [Indexed: 12/14/2022]
Abstract
Alexander Disease (AxD) is a "gliopathy" caused by toxic, dominant gain-of-function mutations in the glial fibrillary acidic protein (GFAP) gene. Two distinct types of AxD exist. Type I AxD affected individuals develop cerebral symptoms by 4 years of age and suffer from macrocephaly, seizures, and physical and mental delays. As detection and diagnosis have improved, approximately half of all AxD patients diagnosed have onset >4 years and brainstem/spinal cord involvement. Type II AxD patients experience ataxia, palatal myoclonus, dysphagia, and dysphonia. No study has examined a mechanistic link between the GFAP mutations and caudal symptoms present in type II AxD patients. We demonstrate that two key astrocytic functions, the ability to regulate extracellular glutamate and to take up K(+) via K+ channels, are compromised in hindbrain regions and spinal cord in AxD mice. Spinal cord astrocytes in AxD transgenic mice are depolarized relative to WT littermates, and have a three-fold reduction in Ba(2+) -sensitive Kir4.1 mediated currents and six-fold reduction in glutamate uptake currents. The loss of these two functions is due to significant decreases in Kir4.1 (>70%) and GLT-1 (>60%) protein expression. mRNA expression for KCNJ10 and SLC1A2, the genes that code for Kir4.1 and GLT-1, are significantly reduced by postnatal Day 7. Protein and mRNA reductions for Kir4.1 and GLT-1 are exacerbated in AxD models that demonstrate earlier accumulation of GFAP and increased Rosenthal fiber formation. These findings provide a mechanistic link between the GFAP mutations/overexpression and the symptoms in those affected with Type II AxD.
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Affiliation(s)
- Heather R Minkel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Tooba Z Anwer
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Kara M Arps
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael Brenner
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michelle L Olsen
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
- Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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7
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Abdallah C. Anaesthesia and orphan disease: anaesthesia for Gomez-Lopez-Hernandez syndrome. Eur J Anaesthesiol 2015; 32:218-220. [PMID: 25226063 DOI: 10.1097/eja.0000000000000157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Affiliation(s)
- Claude Abdallah
- From the Division of Anaesthesiology, Children's National Medical Center, The George Washington University Medical Center, Washington, District of Columbia, USA
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8
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Bogacka I, Roane DS, Xi X, Zhou J, Li B, Ryan DH, Martin RJ. Expression Levels of Genes Likely Involved in Glucose-sensing in the Obese Zucker Rat Brain. Nutr Neurosci 2013; 7:67-74. [PMID: 15279492 DOI: 10.1080/10284150410001710401] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
It has been suggested that certain cells in the brain, like pancreatic beta-cells, use glucose transporter-2 (GLUT-2), glucokinase and glucagon-like peptide-1 receptor (GLP-1R) to sense glucose in the service of multiple aspects of energy balance. The obese Zucker rat displays numerous disturbances in energy homeostasis and may provide a model of dysfunctional expression of genes related to nutrient control systems. Using real-time RT-PCR we measured gene expression for three of the pancreatic glucose-sensing markers and neuropeptide Y (NPY) in the medial, lateral hypothalamus and hindbrain of lean and obese Zucker rats of both genders. Additionally, we measured circulating levels of glucose, leptin, insulin, corticosterone and glucagon. The results indicate that GLUT-2 mRNA expression is decreased, whereas glucokinase is increased in the hindbrain of obese rats. NPY mRNA level is significantly higher, whereas GLP-1R is significantly lower in the medial hypothalamus in obese individuals. Gender-related differences were found in the hindbrain and medial hypothalamus for GLUT-2 and in the lateral hypothalamus for GLP-1R and they may be related to the fact that the female Zucker rats do not develop diabetes as readily as males. Furthermore, the hindbrain may be an important site for glucose-sensing where major phenotypic changes occur for glucose-sensing genes expression.
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Affiliation(s)
- Iwona Bogacka
- Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Road, Baton Rouge, LA 70808, USA
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9
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Lackovicova L, Gaykema RP, Banovska L, Kiss A, Goehler LE, Mravec B. The time-course of hindbrain neuronal activity varies according to location during either intraperitoneal or subcutaneous tumor growth in rats: single Fos and dual Fos/dopamine β-hydroxylase immunohistochemistry. J Neuroimmunol 2013; 260:37-46. [PMID: 23673146 DOI: 10.1016/j.jneuroim.2013.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 03/22/2013] [Accepted: 04/10/2013] [Indexed: 01/28/2023]
Abstract
Neuronal activity in the nucleus of the solitary tract, ventrolateral medulla, area postrema, and parabrachial nucleus was studied in rats with intraperitoneal or subcutaneous tumors on the 7th, 14th, 21st, and 28th day after injection of fibrosarcoma tumor cells. We found that the number of Fos and dopamine β-hydroxylase immunopositive neurons differs between animals with intraperitoneal and subcutaneous tumors and also between tumor-bearing rats at different times following injection. Our data indicate that responses of the brainstem structures to peripheral tumor growth depend on the localization as well as the stage of the tumor growth.
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Affiliation(s)
- Lubica Lackovicova
- Institute of Experimental Endocrinology, Slovak Academy of Sciences, Vlarska 3, 83306 Bratislava, Slovakia
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Pineda R, Beattie CE, Hall CW. Closed-loop neural stimulation for pentylenetetrazole-induced seizures in zebrafish. Dis Model Mech 2013; 6:64-71. [PMID: 22822044 PMCID: PMC3529339 DOI: 10.1242/dmm.009423] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Accepted: 06/29/2012] [Indexed: 11/20/2022] Open
Abstract
Neural stimulation can reduce the frequency of seizures in persons with epilepsy, but rates of seizure-free outcome are low. Vagus nerve stimulation prevents seizures by continuously activating noradrenergic projections from the brainstem to the cortex. Cortical norepinephrine then increases GABAergic transmission and increases seizure threshold. Another approach, responsive nervous stimulation, prevents seizures by reactively shocking the seizure onset zone in precise synchrony with seizure onset. The electrical shocks abort seizures before they can spread and manifest clinically. The goal of this study was to determine whether a hybrid platform in which brainstem activation triggered in response to impending seizure activity could prevent seizures. We chose the zebrafish as a model organism for this study because of its ability to recapitulate human disease, in conjunction with its innate capacity for tightly controlled high-throughput experimentation. We first set out to determine whether electrical stimulation of the zebrafish hindbrain could have an anticonvulsant effect. We found that pulse train electrical stimulation of the hindbrain significantly increased the latency to onset of pentylenetetrazole-induced seizures, and that this apparent anticonvulsant effect was blocked by noradrenergic antagonists, as is also the case with rodents and humans. We also found that the anticonvulsant effect of hindbrain stimulation could be potentiated by reactive triggering of single pulse electrical stimulations in response to impending seizure activity. Finally, we found that the rate of stimulation triggering was directly proportional to pentylenetetrazole concentration and that the stimulation rate was reduced by the anticonvulsant valproic acid and by larger stimulation currents. Taken as a whole, these results show that that the anticonvulsant effect of brainstem activation can be efficiently utilized by reactive triggering, which suggests that alternative stimulation paradigms for vagus nerve stimulation might be useful. Moreover, our results show that the zebrafish epilepsy model can be used to advance our understanding of neural stimulation in the treatment of epilepsy.
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Affiliation(s)
- Ricardo Pineda
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
- Center for Molecular Neurobiology, The Ohio State University, Columbus, OH 43210, USA
| | - Christine E. Beattie
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
- Center for Molecular Neurobiology, The Ohio State University, Columbus, OH 43210, USA
| | - Charles W. Hall
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
- Department of Neurology, The Ohio State University, Columbus, OH 43210, USA
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Guclu B, Sindou M, Meyronet D, Streichenberger N, Simon E, Mertens P. Cranial nerve vascular compression syndromes of the trigeminal, facial and vago-glossopharyngeal nerves: comparative anatomical study of the central myelin portion and transitional zone; correlations with incidences of corresponding hyperactive dysfunctional syndromes. Acta Neurochir (Wien) 2011; 153:2365-75. [PMID: 21947457 DOI: 10.1007/s00701-011-1168-1] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 09/12/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the anatomy of the central myelin portion and the central myelin-peripheral myelin transitional zone of the trigeminal, facial, glossopharyngeal and vagus nerves from fresh cadavers. The aim was also to investigate the relationship between the length and volume of the central myelin portion of these nerves with the incidences of the corresponding cranial dysfunctional syndromes caused by their compression to provide some more insights for a better understanding of mechanisms. METHODS The trigeminal, facial, glossopharyngeal and vagus nerves from six fresh cadavers were examined. The length of these nerves from the brainstem to the foramen that they exit were measured. Longitudinal sections were stained and photographed to make measurements. The diameters of the nerves where they exit/enter from/to brainstem, the diameters where the transitional zone begins, the distances to the most distal part of transitional zone from brainstem and depths of the transitional zones were measured. Most importantly, the volume of the central myelin portion of the nerves was calculated. Correlation between length and volume of the central myelin portion of these nerves and the incidences of the corresponding hyperactive dysfunctional syndromes as reported in the literature were studied. RESULTS The distance of the most distal part of the transitional zone from the brainstem was 4.19 ± 0.81 mm for the trigeminal nerve, 2.86 ± 1.19 mm for the facial nerve, 1.51 ± 0.39 mm for the glossopharyngeal nerve, and 1.63 ± 1.15 mm for the vagus nerve. The volume of central myelin portion was 24.54 ± 9.82 mm(3) in trigeminal nerve; 4.43 ± 2.55 mm(3) in facial nerve; 1.55 ± 1.08 mm(3) in glossopharyngeal nerve; 2.56 ± 1.32 mm(3) in vagus nerve. Correlations (p < 0.001) have been found between the length or volume of central myelin portions of the trigeminal, facial, glossopharyngeal and vagus nerves and incidences of the corresponding diseases. CONCLUSION At present it is rather well-established that primary trigeminal neuralgia, hemifacial spasm and vago-glossopharyngeal neuralgia have as one of the main causes a vascular compression. The strong correlations found between the lengths and volumes of the central myelin portions of the nerves and the incidences of the corresponding diseases is a plea for the role played by this anatomical region in the mechanism of these diseases.
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Affiliation(s)
- Bulent Guclu
- Department of Neurosurgery, Hopital Neurologique Pierre Wertheimer, University of Lyon 1, Lyon, France.
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12
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Barkovich AJ, Millen KJ, Dobyns WB. A developmental and genetic classification for midbrain-hindbrain malformations. Brain 2009; 132:3199-230. [PMID: 19933510 PMCID: PMC2792369 DOI: 10.1093/brain/awp247] [Citation(s) in RCA: 217] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 08/04/2009] [Accepted: 08/21/2009] [Indexed: 01/30/2023] Open
Abstract
Advances in neuroimaging, developmental biology and molecular genetics have increased the understanding of developmental disorders affecting the midbrain and hindbrain, both as isolated anomalies and as part of larger malformation syndromes. However, the understanding of these malformations and their relationships with other malformations, within the central nervous system and in the rest of the body, remains limited. A new classification system is proposed, based wherever possible, upon embryology and genetics. Proposed categories include: (i) malformations secondary to early anteroposterior and dorsoventral patterning defects, or to misspecification of mid-hindbrain germinal zones; (ii) malformations associated with later generalized developmental disorders that significantly affect the brainstem and cerebellum (and have a pathogenesis that is at least partly understood); (iii) localized brain malformations that significantly affect the brain stem and cerebellum (pathogenesis partly or largely understood, includes local proliferation, cell specification, migration and axonal guidance); and (iv) combined hypoplasia and atrophy of putative prenatal onset degenerative disorders. Pertinent embryology is discussed and the classification is justified. This classification will prove useful for both physicians who diagnose and treat patients with these disorders and for clinical scientists who wish to understand better the perturbations of developmental processes that produce them. Importantly, both the classification and its framework remain flexible enough to be easily modified when new embryologic processes are described or new malformations discovered.
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Affiliation(s)
- A James Barkovich
- Neuroradiology Room L371, University of California at San Francisco, 505 Parnassus Avenue, San Francisco, CA 94143-0628, USA.
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Melle C, Ernst G, Grosheva M, Angelov DN, Irintchev A, Guntinas-Lichius O, von Eggeling F. Proteomic analysis of microdissected facial nuclei of the rat following facial nerve injury. J Neurosci Methods 2009; 185:23-8. [PMID: 19748522 DOI: 10.1016/j.jneumeth.2009.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 08/10/2009] [Accepted: 09/01/2009] [Indexed: 12/19/2022]
Abstract
Recent studies using molecular and genetic techniques just have started to elucidate the complex process that drives successful peripheral nerve regeneration. Introducing proteomics to this field, we unilaterally performed a facial nerve axotomy in 13 adult Wistar rats. Seven days later, a total of 40 20-microm coronary cryostat sections of the operated and contralateral unoperated nucleus facialis were microdissected. On the one hand, microdissected areas were pooled for each side, lysed and applied to ProteinChip Arrays. On the other hand, one microdissected area from the right and left facial nucleus each was directly placed on the affinity chromatographic array. Facial motoneurons were lysed in situ and released their proteins to spatially defined points. 215 laser addressable distinct positions across the surface of the spot enabled a high spatial resolution of measured protein profiles for the analysed tissue area. Protein profiles of the single positions were plotted over the used tissue section to visualize their distribution. The comparative analysis of the protein lysates from operated and normal nuclei facialis revealed, for both approaches used, differentially expressed proteins. Although by direct application of one cryostat section only a few hundred motoneurons were analysed, results comparable to these using lysates were obtained. Additionally, the applied technique revealed differences in the intensity distribution of several proteins of unknown function in the lesioned in comparison to the contralateral normal facial nucleus. This proteomic analysis with ultra high sensitivity paired with potential for a spatial resolution is a promising methodology for peripheral nerve regeneration studies.
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Affiliation(s)
- Christian Melle
- Core Unit Chip Application (CUCA), Institute of Human Genetics and Anthropology, University Hospital Jena, Jena, Germany
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14
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Tubbs RS, Shoja MM, Ardalan MR, Shokouhi G, Loukas M. Hindbrain herniation: A review of embryological theories. Ital J Anat Embryol 2008; 113:37-46. [PMID: 18491453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Herniation of the hindbrain outside of the setting of intracranial hypertension, trauma, and brain tumors is an uncommon phenomenon with estimated incidence of less than 1%. In the late 1890's, Hans Chiari, a German pathologist, classified hindbrain herniation into three forms. This classification was then extended to include six types. We reviewed the current literature for the proposed embryological theories as well as the potential genetic mutations/syndromes associated with the hindbrain herniation or Chiari malformation. The review is illustrated by a unique cadaver with Chiari type I malformation (i.e. herniation of the cerebellar tonsils through the foramen magnum). Finally, it seems that no single theory could explain all forms of the Chiari malformation, and that this malformation might be a heterogeneous entity.
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Affiliation(s)
- R Shane Tubbs
- Department of Cell Biology and Section of Pediatric Neurosurgery, University of Alabama at Birmingham, Alabama, USA
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15
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Abstract
Recent neuropathologic studies suggest that Parkinson disease (PD) does not begin in the substantia nigra compacta (SNc) but only involves this region later in the course of the disease. It is proposed that once the SNc is affected by the original pathobiological process (for example, protein aggregation), additional processes more specific to dopaminergic neurons are triggered (including sources of oxidative stress such as increased dopamine turnover, reduced levels of reduced glutathione, increased iron, and the presence of neuromelanin, as well as altered calcium homeostasis and excitotoxicity). This results in an acceleration of cell loss in the SNc, causing nigrostriatal degeneration to both reach a threshold for symptoms in advance of earlier affected brain areas and progress more rapidly than other aspects of the disease. Neuroprotective therapy directed solely at more general biologic processes may not have sufficient effects on this accelerated degeneration in the SNc, while neuroprotective therapy designed exclusively to slow the progression of dopaminergic cell loss will not alter the progression of the nondopaminergic symptoms that contribute the greatest disability in the later stages of the disease. Effective disease-modifying therapy may require a cocktail combining treatments designed to address the basic mechanisms of the neurodegeneration and the additional biologic processes specific to the dopaminergic SNc. This hypothesis has implications for the development of disease-modifying therapy and the interpretation of endpoints of clinical trials evaluating the efficacy of such treatments.
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Affiliation(s)
- Anthony E Lang
- Movement Disorders Centre, Toronto Western Hospital, Toronto, ON, Canada.
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Druse MJ, Tajuddin NF, Gillespie RA, Le P. The effects of ethanol and the serotonin(1A) agonist ipsapirone on the expression of the serotonin(1A) receptor and several antiapoptotic proteins in fetal rhombencephalic neurons. Brain Res 2006; 1092:79-86. [PMID: 16687129 DOI: 10.1016/j.brainres.2006.02.065] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 02/16/2006] [Accepted: 02/20/2006] [Indexed: 01/11/2023]
Abstract
Previously, this laboratory demonstrated that ethanol reduces the number of developing serotonin (5-HT)-containing neurons by increasing apoptosis. We also found that 5-HT(1A) agonists attenuate the proapoptotic effects of ethanol and the ethanol-mediated reduction of fetal 5-HT neurons. These neuroprotective effects are mediated in part by the ability of 5-HT(1A) agonists to activate the phosphatidyl 3'-kinase (PI-3K) prosurvival pathway. NF-kappaB is one of the downstream effectors activated by this pathway. In the present study, we used quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the effects of 50mM ethanol and 100nM of ipsapirone, a 5-HT(1A) agonist, on the expression of several NF-kappaB-dependent antiapoptotic genes: X-linked inhibitor of apoptosis protein (XIAP), cIAP1, cIAP2, Bcl-2, and Bcl-xl. We also investigated the effects of ethanol and ipsapirone on the expression of the gene encoding the 5-HT(1A) receptor. The results demonstrate that ethanol reduces the expression of several prosurvival genes: XIAP, cIAP1, cIAP2, Bcl-2, and Bcl-xl. Importantly, the ethanol-mediated reduction in the expression of XIAP and Bcl-xl was prevented by co-treatment with ipsapirone. Thus, the damaging effects of ethanol are likely to involve a reduction in several prosurvival proteins. Moreover, the protective effects of ipsapirone on ethanol-treated neurons might involve their ability to prevent the reduction of XIAP and Bcl-xl. Although ipsapirone treatment decreased the expression of cIAP1, Bcl-2, and Bcl-xl in control neurons, our prior studies suggest that their survival is not reduced by ipsapirone. We also observed an increased expression of the 5-HT(1A) receptor in ipsapirone-treated control neurons.
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Affiliation(s)
- Mary J Druse
- Division of Molecular and Cellular Biochemistry, Loyola University Stritch School of Medicine, 2160 S. First Avenue, Maywood, IL 60153, USA.
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McGirt MJ, Nimjee SM, Floyd J, Bulsara KR, George TM. Correlation of cerebrospinal fluid flow dynamics and headache in Chiari I malformation. Neurosurgery 2006; 56:716-21; discussion 716-21. [PMID: 15792510 DOI: 10.1227/01.neu.0000156203.20659.14] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 11/06/2004] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE The management of patients with a Chiari I malformation who present with headaches alone remains unclear. We studied the cerebrospinal fluid (CSF) flow dynamics of Chiari I malformation patients presenting with headaches alone so as to identify headache types that are associated with CSF flow obstruction versus those that may be unrelated to Chiari I malformations. METHODS Preoperative cine phase-contrast magnetic resonance imaging of the craniocervical junction was prospectively performed in 33 patients presenting with headaches alone and a Chiari I malformation (tonsillar ectopia >5 mm below the foramen magnum). Headaches were classified as frontal, occipital, or generalized. CSF flow dynamics were then prospectively compared with presenting symptomatology. A subgroup of 17 patients underwent surgical decompression of the Chiari I malformations. RESULTS Patients with frontal or generalized headaches were 10-fold less likely to demonstrate obstructed CSF flow (odds ratio, 0.10; 95% confidence interval, 0.02-0.52) and 8-fold less likely to have tonsillar descent greater than 7 mm (odds ratio, 0.12; 95% confidence interval, 0.03-0.62) compared with patients with occipital headaches. Adjusting for degree of tonsillar herniation in multivariate analysis, frontal and generalized headaches remained independently associated with nonobstructed CSF flow pathological findings, whereas occipital headaches remained associated with obstructed CSF flow independent of tonsil location (odds ratio, 5.84; 95% confidence interval, 1.01-34.28). In the surgical group, all patients with obstructed CSF flow did well compared with the group with normal flow, regardless of headache location. CONCLUSION Regardless of the degree of tonsillar ectopia, occipital headaches were strongly associated with hindbrain CSF flow abnormalities, whereas frontal and generalized headaches were not. Normal magnetic resonance imaging-cine CSF flow in the setting of a Chiari I malformation and frontal headaches alone suggests that frontal headaches are not pathologically or causatively associated with the Chiari I malformation in the vast majority of patients. Frontal headaches with obstructed flow may respond to surgery.
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Affiliation(s)
- Matthew J McGirt
- Department of Neurosurgery, Johns Hopkins Medical Center, Baltimore, Maryland, USA
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Waage-Baudet H, Dunty WC, Dehart DB, Hiller S, Sulik KK. Immunohistochemical and microarray analyses of a mouse model for the smith-lemli-opitz syndrome. Dev Neurosci 2006; 27:378-96. [PMID: 16280635 DOI: 10.1159/000088453] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 06/05/2005] [Indexed: 12/30/2022] Open
Abstract
The Smith-Lemli-Opitz syndrome is a mental retardation/malformation syndrome with behavioral components of autism. It is caused by a deficiency in 3beta-hydroxysteroid-Delta7-reductase (DHCR7), the enzyme required for the terminal enzymatic step of cholesterol biosynthesis. The availability of Smith-Lemli-Opitz syndrome mouse models has made it possible to investigate the genesis of the malformations associated with this syndrome. Dhcr7 gene modification (Dhcr7-/-) results in neonatal lethality and multiple organ system malformations. Pathology includes cleft palate, pulmonary hypoplasia, cyanosis, impaired cortical response to glutamate, and hypermorphic development of hindbrain serotonergic neurons. For the current study, hindbrain regions microdissected from gestational day 14 Dhcr7-/-, Dhcr7+/- and Dhcr7+/+ fetuses were processed for expression profiling analyses using Affymetrix oligonucleotide arrays and filtered using statistical significance (S-score) of change in gene expression. Of the 12,000 genes analyzed, 91 were upregulated and 98 were downregulated in the Dhcr7-/- hindbrains when compared to wild-type animals. Fewer affected genes, representing a reduced affect on these pathways, were identified in heterozygous animals. Hierarchical clustering identified altered expression of genes associated with cholesterol homeostasis, cell cycle control and apoptosis, neurodifferentiation and embryogenesis, transcription and translation, cellular transport, neurodegeneration, and neuronal cytoskeleton. Of particular interest, Dhcr7 gene modification elicited dynamic changes in genes involved in axonal guidance. In support of the microarray findings, immunohistochemical analyses of the netrin/deleted in colorectal cancer axon guidance pathway illustrated midline commissural deficiencies and hippocampal pathfinding errors in Dhcr7-/- mice. The results of these studies aid in providing insight into the genesis of human cholesterol-related birth defects and neurodevelopmental disorders and highlight specific areas for future investigation.
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Affiliation(s)
- H Waage-Baudet
- Department of Cell and Developmental Biology, The University of North Carolina, Chapel Hill, N.C. 27599-7178, USA
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Abstract
The cranial autonomic symptoms (CAS) in patients with cluster headache (CH) are considered to occur as a result of intense ophthalmic division pain. Five CH patients underwent transection of the trigeminal nerve root but continued to experience periodic CAS without pain, whereas another five patients continued to experience typical cluster headaches. These findings confirm that CH is generated by a central pacemaker and the pain may be expressed without activation of the peripheral trigeminovascular network.
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Affiliation(s)
- Helen Lin
- The Mayo Clinic, Scottsdale, AZ 85259, USA
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20
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Rodgers SJ, Bolognese PA. Managing chronic headaches in the clinic. Int J Clin Pract 2005; 59:864-5; author reply 865. [PMID: 15963221 DOI: 10.1111/j.1368-5031.2005.00566b.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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21
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Sabadash VV, Fadyukova OE, Koshelev VB. Reactivity of Rat Basilar Artery to Serotonin after Short-Term Ischemia of Hindbrain and during Chronic Vertebrobasilar Insufficiency. Bull Exp Biol Med 2005; 139:408-10. [PMID: 16027866 DOI: 10.1007/s10517-005-0307-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Contractile responses of the basilar artery to serotonin were examined in vitro on two models of circulation disturbances in the vertebrobasilar region of the brain. Two days after 30-min reversible occlusion of vertebral arteries, the sensitivity of the basilar artery to serotonin decreased, while chronic vertebrobasilar insufficiency had no effect on serotonin-induced contraction.
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Affiliation(s)
- V V Sabadash
- Fundamental Medicine Faculty, M. V. Lomonosov Moscow State University, Russia
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22
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van Calenbergh F, Demaerel P, Sciot R, van Gool S. Long-term survival in a child with a brain stem dermoid cyst. ACTA ACUST UNITED AC 2005; 63:261-3; discussion 263-4. [PMID: 15734520 DOI: 10.1016/j.surneu.2004.04.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2004] [Accepted: 04/19/2004] [Indexed: 11/21/2022]
Abstract
BACKGROUND Brain stem dermoid cysts are very rare lesions, and in most, the outcome has been very poor. Because of the dangers of dissecting the cyst wall away from the brain stem parenchyma, some authors have advocated not to attempt a radical resection. METHODS We describe a child in whom the brain stem dermoid cyst recurred rapidly after a conservative approach. We therefore attempted a radical removal. RESULTS During surgery, the almost complete resection of the cyst wall was not very difficult, leading to an apparent cure after 4 years. CONCLUSION In exceptional cases, it may be possible to remove a brain stem dermoid cyst without prohibitive morbidity and with long-term cure.
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Affiliation(s)
- Frank van Calenbergh
- Department of Neurosurgery, University Hospital Gasthuisberg, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium.
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23
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Demaerel P, Morel C, Lagae L, Wilms G. Partial rhombencephalosynapsis. AJNR Am J Neuroradiol 2004; 25:29-31. [PMID: 14729524 PMCID: PMC7974185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
We describe an infant in whom partial rhombencephalosynapsis was diagnosed by using MR imaging. The anterior vermis and nodulus were normally developed, but part of the posterior vermis was deficient. There was partial fusion of the hemispheres in the inferior part of the cerebellum. Partial rhombencephalosynapsis is described for the first time, and our findings support the recent embryologic observations.
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Bräuer-Krisch E, Bravin A, Lerch M, Rosenfeld A, Stepanek J, Di Michiel M, Laissue JA. MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility. Med Phys 2003; 30:583-9. [PMID: 12722810 DOI: 10.1118/1.1562169] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Preclinical experiments are carried out with approximately 20-30 microm wide, approximately 10 mm high parallel microbeams of hard, broad-"white"-spectrum x rays (approximately 50-600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. Novel physical microdosimetry (implemented with MOSFET chips in the "edge-on" mode) and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue-equivalent phantom. Such microbeam irradiation causes minimal damage to normal tissues, possible because of rapid repair of their microscopic lesions. Radiation damage from an array of parallel microbeams tends to correlate with the range of peak-valley dose ratios (PVDR). This paper summarizes comparisons of our dosimetric MOSFET measurements with Monte Carlo calculations. Peak doses at depths <22 mm are 18% less than Monte Carlo values, whereas those depths >22 mm and valley doses at all depths investigated (2 mm-62 mm) are within 2-13% of the Monte Carlo values. These results lend credence to the use of MOSFET detector systems in edge-on mode for microplanar irradiation dosimetry.
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Affiliation(s)
- E Bräuer-Krisch
- European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble, France
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25
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Spreux-Varoquaux O, Bensimon G, Lacomblez L, Salachas F, Pradat PF, Le Forestier N, Marouan A, Dib M, Meininger V. Glutamate levels in cerebrospinal fluid in amyotrophic lateral sclerosis: a reappraisal using a new HPLC method with coulometric detection in a large cohort of patients. J Neurol Sci 2002; 193:73-8. [PMID: 11790386 DOI: 10.1016/s0022-510x(01)00661-x] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Glutamate is involved in the degeneration of motor neurons in amyotrophic lateral sclerosis (ALS). However, the aetiology of ALS appears heterogeneous, leading to the possibility that patient subgroups with different pathophysiology may exist. The concentration of glutamate in cerebrospinal fluid (CSF) is measured using a new HPLC method with coulometric detection in a large cohort of ALS patients and controls: 377 ALS patients, 88 neurological patients and 18 normal controls. In ALS patients, and only in these subjects, the existence of two groups was observed, one with normal glutamate concentrations and one (40.8% of ALS patients) with high glutamate concentrations. High glutamate concentrations were correlated with a spinal onset of the disease, more impaired limb function and a higher rate of muscle deterioration. These results suggest that elevations of CSF glutamate concentrations could reflect the intensity of cell insult in the spinal cord. It remains to be determined if the group of patients with high CSF glutamate concentrations represents a specific subgroup of patients in terms of mechanism of disease, or only in terms of the spatial extent of motor neuron insult.
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Affiliation(s)
- Odile Spreux-Varoquaux
- Service de Biochimie-Pharmacologie et d'Anesthésie, Hôpital de Versailles, Le Chesnay, France
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26
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Abstract
Whether progesterone (P(4)) and its metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) have anti-seizure effects through actions in the raphe magnus (NRM) was investigated. Ovariectomized, Long-Evans rats with unilateral implants into the NRM of P(4) or its metabolite, 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) had a significantly lower incidence of myoclonic seizures and less EEG activity following pentylenetetrazol (PTZ; 70 mg/kg, IP) administration than did rats with control implants. Progestin implants that missed the NRM were not effective at reducing ictal activity. Following P(4) implants to the NRM levels of P(4), and following P(4) and 3alpha,5alpha-THP implants to the NRM, 3alpha,5alpha-THP levels in the ventral hindbrain were increased above those seen in rats with control implants. These data suggest that progestins' anti-seizure effects in the NRM may be involve actions of 3alpha,5alpha-THP.
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Affiliation(s)
- C A Frye
- Department of Psychology, The University at Albany-SUNY, 1400 Washington Avenue, Albany, NY 12222, USA.
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Braak E, Sandmann-Keil D, Rüb U, Gai WP, de Vos RA, Steur EN, Arai K, Braak H. alpha-synuclein immunopositive Parkinson's disease-related inclusion bodies in lower brain stem nuclei. Acta Neuropathol 2001; 101:195-201. [PMID: 11307617 DOI: 10.1007/s004010000247] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Advanced silver stains and immunohistochemical reactions against alpha-synuclein were used to detect Parkinson's disease-related cytoskeletal abnormalities in select lower brain stem nuclei. Various types of inclusion bodies including inconspicuous and heretofore unnoted granular particles and thread-like Lewy neurites were visualized. Of the nuclei investigated (gigantocellular reticular nucleus, bulbar raphe nuclei, coeruleus-subcoeruleus area), only lipofuscin- or neuromelanin-laden neuronal types showed a propensity to develop the pathological changes. Neuronal types devoid of pigment deposits remained free of the cytoskeletal abnormalities. Fine, dust-like particles and small globular Lewy bodies were encountered solely within the limits of intraneuronal lipofuscin or neuromelanin deposits.
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Affiliation(s)
- E Braak
- Department of Anatomy, J. W. Goethe-University, Theodor Stern Kai 7, 60590 Frankfurt/Main, Germany.
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Nichter CA, Pavlakis SG, Shaikh U, Cherian KA, Dobrosyzcki J, Porricolo ME, Chatturvedi I. Rhombencephalitis caused by West Nile fever virus. Neurology 2000; 55:153. [PMID: 10891935 DOI: 10.1212/wnl.55.1.153] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- C A Nichter
- Division of Child Neurology and Pediatrics, Bronx Lebanon Hospital Center, New York 10457, USA
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Abstract
Rhombencephalitis due to Listeria monocytogenes is a frequent complication of human listeriosis, inducing a high mortality and severe neurological sequelae despite antibiotic therapy. However, there is no animal model which consistently reproduces clinical rhombencephalitis. Here, we present a model of Listeria rhombencephalitis in gerbils. Animals were inoculated in the middle ears with a low infective dose of L. monocytogenes, thus creating prolonged otitis media with persistent bacteremia. Gerbils developed a severe rhombencephalitis with circling syndrome, paresia, ataxia, rolling movements. The invasion of the central nervous system was visualized on living animals by resonance magnetic imaging and characterized by bacterial growth in the brain, reaching about 10(7) bacteria in the rhombencephalum by day 12 of infection. The histological lesions were mainly located in the brainstem, and consisted in coalescent, necrotic abscesses with perivascular sheaths, mimicking those observed in human rhombencephalitis. Bacteria were detected by electronmicroscopy inside infectious foci, either free in necrotic material or inside inflammatory cells, mainly polymorphonuclear cells. This gerbil model of Listeria rhombencephalitis will be useful to study the molecular mechanisms allowing bacteria to cross the blood-brain barrier, and to evaluate the intracerebral efficacy of antibiotics.
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Affiliation(s)
- S Blanot
- INSERM U411, Faculté de Médecine Necker-Enfants Malades, Paris, France
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Leung FC, Saggerson ED, Clark JB. Hypothyroidism alters the effect of GTP on adenylyl cyclase in forebrain and hindbrain synaptosomal membranes from 15-day-old rats. Int J Dev Neurosci 1996; 14:701-5. [PMID: 8960977 DOI: 10.1016/s0736-5748(96)00072-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The effect of GTP concentration of forskolin-stimulated adenylyl cyclase activity was examined in synaptosomal membranes from 15-day-old rats that were hypothyroid owing to administration of propylthiouracil and a low-iodine diet to the mothers during pregnancy and suckling. In membranes from the forebrain hypothyroidism abolished the overall stimulatory effect of GTP, which was seen in the euthyroid case. In membranes from the hindbrain hypothyroidism had the opposite effect in that there was an enhancement of an overall stimulatory effect of GTP. It is suggested that these findings reflect changes during early development of the brain in the expression of various G-proteins and/or the expression of different isoforms of adenylyl cyclase.
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Affiliation(s)
- F C Leung
- Department of Biochemistry and Molecular Biology, University College London, U.K
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Nishimura T, Mori K. Somatosensory evoked potentials to median nerve stimulation in meningomyelocele: what is occurring in the hindbrain and its connections during growth? Childs Nerv Syst 1996; 12:13-26. [PMID: 8869170 DOI: 10.1007/bf00573849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Twenty patients with meningomyelocele (MMC) and shunted hydrocephalus, ranging in age from 3 to 23 years old, underwent serial recording of short-latency somatosensory evoked potentials (SEPs) to median nerve stimulation, on the basis of which to assess the evolution of dysfunction in the brainstem and its connections (cervical spinal cord, cervical nerve roots, lower cranial nerves). Eighteen patients had Chiari type II malformations, none of which was symptomatic. In all 20 patients, serial SEP recordings were obtained repeatedly after periods ranging from 2 to 7 years. The results were as follows: (1) the ratio of EP-N13 interpeak latencies (IPLs) to body height (BH) tended to lengthen gradually after starting in the normal range with growth. (2) In contrast, the ratio N13-N20 IPLs/BH decreased continuously to the normal range with growth, after initial prolongation. These findings and our earlier studies of brainstem auditory evoked potentials suggest that compression and traction result in strangulation of the cervical spinal cord and kinked medulla as well as stretching of the cervical nerve roots and lower cranial nerves. However, primary intrinsic functional disorders of the brainstem appeared to improve gradually during growth. The natural history of Chiari type II malformations involves these opposing dynamic phenomena in the hindbrain and its connections.
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Affiliation(s)
- T Nishimura
- Department of Neurosurgery, Taiju-Kai Foundation, Kagawa Prefecture, Japan
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Bianchi G, Appollonio I, Piolti R, Pozzi C, Frattola L. Listeria rhombencephalitis: report of two cases with early diagnosis and favourable outcome. Clin Neurol Neurosurg 1995; 97:344-8. [PMID: 8599906 DOI: 10.1016/0303-8467(95)00069-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We present 2 cases of Listeria monocytogenes rhombencephalitis (L-RE), both affecting previously healthy adult men. Each of them developed a diphasic syndrome first characterized by fever, nausea and headache, followed, in a second phase, by severe brain stem dysfunction at the level of the pons, with meningism, multiple cranial nerve palsies, ataxia, and, in one case, seizures. The early examination of the cerebrospinal fluid (CSF) demonstrated the presence of Gram-positive bacilli whose typical characteristics were compatible with those of Listeria, allowing for immediate administration of a specific therapy. Neuroimaging techniques (either CT or MRI) did not provide any evidence of brain stem involvement, and they did not positively contribute to the diagnostic process. The immediate use of a specific antibiotic therapy led to a favourable clinical outcome for both patients.
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Affiliation(s)
- G Bianchi
- Department of Neurology V. University of Milan, San Gerardo Hospital, Monza (Mi), Italy
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Terae S, Miyasaka K, Abe S, Abe H, Tashiro K. Increased pulsatile movement of the hindbrain in syringomyelia associated with the Chiari malformation: cine-MRI with presaturation bolus tracking. Neuroradiology 1994; 36:125-9. [PMID: 8183451 DOI: 10.1007/bf00588077] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Cine-MRI with presaturation bolus tracking was used in patients with syringomyelia associated with a Chiari malformation to study pulsatile movement of the hindbrain, cervical spinal cord, cerebrospinal fluid and the fluid within the syrinx. Nine patients had 13 examinations, 6 preoperative, 3 after syringosubarachnoid shunting and 4 after posterior fossa decompression. Five controls were also examined. Dynamic display of the acquired images demonstrated downward displacement of the presaturation bolus on the cerebellar tonsils and medulla oblongata (or upper cervical cord) at the C1 level in all preoperative examinations and in two patients after syringosubarachnoid shunting but with residual foramen magnum obstruction. Downward displacement of the bolus on the cervical spinal cord was also demonstrated in 7 examinations, but not observed in the controls. Thus, the hind-brain-spinal cord axis showed larger pulsatile movements in patients with foramen magnum obstruction. Based on these observations and a review of the literature, a new theory on the mode of extension of syringomyelia, emphasising the role of increased pulsatile movement of the hind-brain-spinal cord axis is proposed: that the pulsatile movements, together with a one-way valve mechanism in the syrinx cavity act as a "vacuum-pump" to enlarge the syrinx.
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Affiliation(s)
- S Terae
- Department of Radiology, Hokkaido University School of Medicine, Sapporo, Japan
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Lantéri-Minet M, Weil-Fugazza J, de Pommery J, Menétrey D. Hindbrain structures involved in pain processing as revealed by the expression of c-Fos and other immediate early gene proteins. Neuroscience 1994; 58:287-98. [PMID: 8152540 DOI: 10.1016/0306-4522(94)90035-3] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have used the evoked expression of the immediate early gene-encoded proteins (c-Fos, Fos B, Jun B, Jun D, c-Jun and Krox-24) to monitor sensory processing in the hindbrain structures of rats undergoing somatic inflammation. Experiments were performed on freely moving animals that did not experience constraints other than those imposed by the disease itself. Local injections of chemicals were used to cause subcutaneous inflammation of the plantar foot or monoarthritis by intracapsular injection. Labelling was studied at survival times that corresponded either to the time points of maximum labelling in the spinal cord (4 h for the subcutaneous model, 24 h and two weeks for the monoarthritis model) or at survival times that corresponded to the chronic phase of monoarthritis evolution (six, nine and 15 weeks). Controls consisted of freely moving, unstimulated animals. Basal expression was observed for all immediate early genes and in a variety of structures, but always remained moderate. All immediate early gene-encoded protein expressions except c-Jun were evoked, but except for c-Fos, and to a lesser extent Jun D, intensities of staining always remained faint. The following results will be mainly based on c-Fos expression, as this protein proved to be the most effective marker for all the survival times studied. Somatic pain evoked c-Fos expression in a subset of discrete subregions of both the caudal medulla oblongata and transitional areas of the pontomesencephalic junction. In the caudal medulla oblongata, structures involved were the caudal intermediate reticular nucleus, the subnucleus reticularis dorsalis, the ventrolateral reticular formation and the lateral paragigantocellular nucleus. Structures involved at the pontomesencephalic junction level mostly included the superior and dorsal lateral subnuclei of the parabrachial area, the nucleus cuneiformis and the most caudal portions of the lateral central gray, also including the laterodorsal tegmental nucleus; labelling in other lateral subnuclei of the parabrachial area always remained moderate. Staining in the caudal reticular areas was evident only at short survival times (4 and 24 h survival times in subcutaneous and monoarthritis models, respectively). Staining in nuclei of the pontomesencephalic junction was evident in all cases except for the very long survival periods (six to 15 weeks) of monoarthritis. In all cases staining was bilateral with contralateral predominance with regard to the stimulated limb. The present work demonstrates that hindbrain structures involved in somatic pain processing can be effectively identified in behaving animals and that c-Fos is the most reliable activity marker in this case.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- M Lantéri-Minet
- Institut National de la Santé et de la Recherche Médicale Unité 161, Paris, France
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Lantéri-Minet M, Isnardon P, de Pommery J, Menétrey D. Spinal and hindbrain structures involved in visceroception and visceronociception as revealed by the expression of Fos, Jun and Krox-24 proteins. Neuroscience 1993; 55:737-53. [PMID: 8413935 DOI: 10.1016/0306-4522(93)90439-m] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have used the evoked expression of the immediate early gene-encoded proteins (Krox-24, c-Fos, Fos B, Jun D, Jun B, c-Jun) to monitor visceral processing in both the spinal cord and hindbrain structures of rats undergoing either mechanical colorectal or chemical intraperitoneal stimulation. Experiments were conducted under controlled volatile anaesthesia to suppress affective reactions that visceral stimulations may induce. The results refer to the effects of anaesthesia alone, and of both innocuous and noxious stimulations. Non-nociceptive and nociceptive stimulation but not anaesthesia were effective in evoking c-Fos, c-Jun, Jun B and Krox-24 expressions in the spinal cord. Intraperitoneal injections labelled cells mostly at the thoracolumbar junction levels, while colorectal distension labelled cells mostly at the lumbrosacral junction levels. Labelling was widely distributed throughout the gray matter including superficial layers, deep dorsal horn, lamina X and sacral parasympathetic columns. Krox-24- and, to a lesser degree, c-Jun-labelled cells were quite numerous in the superficial layers of the dorsal horn; Jun B, and especially c-Fos, were very effective in demonstrating inputs to all parts of the spinal cord. Both anaesthesia and noxious visceral stimulation were effective in evoking c-Fos, Krox-24 and Jun B expressions in discrete hindbrain subregions. The structures which are primarily labelled under anaesthesia are the rostral ventrolateral medulla, the external medial and lateral nuclei of the parabrachial area, the medial and dorsal subnuclei of the nucleus of the solitary tract, the area postrema, the central gray including pars alpha and nucleus O, the nucleus beta of the inferior olive, the locus coeruleus, and the inferior colliculi and adjacent parts of central gray. The structures which are primarily labelled following noxious visceral stimulation are the caudal intermediate reticular nucleus as part of the caudalmost ventrolateral medulla and the superior lateral nucleus of the rostrolateral parabrachial area. Labelling in the caudal intermediate reticular nucleus was maximal for colorectal distension. Labelling in the superior lateral nucleus was specific to peritoneal inflammation. The Edinger-Westphal nucleus is a structure in which noxious-evoked labelling was superposed onto the anaesthesia-evoked labelling. Nociception-evoked overexpression in this nucleus was maximal for intraperitoneal inflammation. The present work demonstrates that the central effects induced by either anaesthesia or visceroception including pain can be effectively monitored through the induction of an array of immediate early genes.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- M Lantéri-Minet
- Institut National de la Santé et de la Recherche Médicale Unité 161, Paris, France
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Abstract
In utero ethanol exposure impairs the development of several neurotransmitter systems, including the serotonergic system. However, at present the mechanism by which in utero ethanol exposure damages the developing brain is unknown. This research examined the possibility that ethanol directly impairs the development of serotonergic neurons. This hypothesis was assessed by examining the content of serotonin (5-HT), 5-HT uptake, and 5-HT immunopositive neurons in cultures of fetal rhombencephalic neurons that were exposed to ethanol for 4 days in vitro. In addition, the effects of in vitro ethanol exposure on protein and DNA content of cultured rhombencephalic neurons were determined. These studies demonstrated that a 4-day exposure of cultured rhombencephalic neurons to 50 to 300 mg ethanol/dl did not affect 5-HT content, 5-HT uptake, or the proportion of 5-HT immunopositive neurons. In addition, this ethanol exposure had no significant effect on protein or DNA content. Additional studies, using a 4-day exposure to 450 mg ethanol/dl also did not detect significant differences in 5-HT uptake or in protein or DNA content. The marked differences in the findings of the present in vitro and previous in vivo studies may be due to the fact that the ethanol exposure in vivo was longer than that in vitro, and included the period of early development of serotonergic neurons and their progenitors. Alternatively, the differences may be due to ethanol-associated alterations in maternal or fetal factors (e.g., hormones, amino acids, and growth factors) that are necessary for the normal development of the serotonergic system in vivo. Normal concentrations of such factors in the serum-containing media may have protected the cultured neurons from the damaging effects of ethanol.
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Affiliation(s)
- D K Lokhorst
- Neuroscience Program, Loyola University of Chicago, Stritch School of Medicine, Maywood, Illinois 60153
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Abstract
Various orders of binomial spatial modulation of magnetization sequences up to (1 4 6 4 1) have been tested to find the optimum sequence for clinical application. Stripe width, stripe sharpness and the tolerance of the sequences to radiofrequency non-linearity have been investigated. The (1 3 3 1) sequence was found to be a good compromise between competing design criteria, and its application to viewing pulsatile cerebrospinal fluid motion is described.
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Affiliation(s)
- S C Wayte
- Department of Clinical Physics and Bioengineering, Walsgrave Hospital, Coventry, UK
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Abstract
Hamsters were exposed to intense tones (10 kHz) at levels and durations sufficient to cause stereocilia lesions. The purpose was to determine how the tonotopic map of the dorsal cochlear nucleus (DCN) readjusts to loss of receptor sensitivity. Neural population thresholds and tonotopic organization was mapped over the surface of the DCN in normal unexposed animals and those showing tone-induced lesions. The results indicate that cochlear lesions characterized mainly by loss of stereocilia in a restricted portion of the organ of Corti cause changes in a corresponding region of the tonotopic map which reflect primarily changes in the shape and thresholds of neural tuning curves. In many cases the center of the lesion was represented in the DCN as a distinct characteristic frequency (CF) gap in the tonotopic map in which responses were either extremely weak or absent. In almost all cases the map area representing the center of the lesion was bordered by an expanded region of near-constant CF, a feature superficially suggestive of map reorganization. These expanded map areas had abnormal tip thresholds and showed other features suggesting that their CFs had been shifted downward by distortion and deterioration of their original tips. Such changes in neural tuning are similar to those observed by others in the auditory nerve following acoustic trauma, and thus would seem to have a peripheral origin. Thus, it is not necessary to invoke plastic changes in the cochlear nucleus to explain the changes observed in the tonotopic map.
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Affiliation(s)
- J A Kaltenbach
- Department of Audiology, Wayne State University School of Medicine, Detroit, Michigan 48201
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Abstract
This reply to John F Catherwood's criticism of brain-related criteria for death argues that brainstem criteria are neither reductionist nor do they presuppose a materialist theory of mind. Furthermore, it is argued that brain-related criteria are compatible with the majority of religious views concerning death.
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Abstract
Five children with severe developmental delay had intractable fits of various types but tonic, often extensor, seizures were prominent from an early stage. Onset was in the neonatal period in 4 cases. EEGs were severely abnormal and showed a "burst-suppression" pattern in the first months of life. There were no metabolic or consistent neuroradiological abnormalities. A distinctive form of dentato-olivary dysplasia was found in all cases. Inferior olives were hook-shaped, coarse and lacking undulations, while dentate nuclei showed a compact arrangement of interconnected islands. The clinico-pathological findings form a novel nosological entity.
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Affiliation(s)
- B N Harding
- Department of Neuropathology, Hospital for Sick Children, London, U.K
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Abstract
We report two patients with posterior fossa neoplasms who demonstrated asymmetrically impaired horizontal ocular pursuit documented with electrooculography. One patient had impaired pursuit contralateral to a pontomedullary lesion, whereas the second patient had impaired pursuit ipsilateral to a pontocerebellar lesion. These patients demonstrate that posterior fossa lesions may impair ocular pursuit either contralaterally or ipsilaterally unlike cerebral hemispheric lesions, which impair ocular pursuit ipsilaterally or bilaterally.
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Affiliation(s)
- J M Furman
- Department of Otolaryngology, University of Pittsburgh School of Medicine, PA
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Abstract
Temporal integration functions were measured, before and after a sound-induced hearing loss, in 5 cats using trains of electrical pulses applied to auditory nuclei in the brainstem. The 8 stimuli ranged from 1 pulse (0.25 ms duration) to 16 pulses (0.25 ms pulses spaced over 240 ms). The stimuli were applied to inferior colliculus or cochlear nucleus via permanently implanted electrodes. One electrode was tested extensively in each animal to obtain 10 sets of behaviorally-measured electrical detection thresholds counterbalanced across stimuli. The animal was then exposed to a 110 dB SPL, 2 kHz tone for 48 h and pre- and post-exposure audiograms were measured. The mean permanent threshold shift for acoustic stimuli was 48.5 dB. Another 10 thresholds for each of the 8 electrical stimuli were then measured. In the normal hearing animals, the mean slope of the temporal integration function for electrical stimulation was -7.6 dB per factor of 10 pulses. Alternatively, the mean time constant was 139 ms. In the hearing impaired animals, the slope was reduced to -1.5 dB per factor of 10 pulses, which corresponded to a mean time constant of 17 ms. In addition, the hearing impaired animals showed a decreased threshold for the electrical stimuli (stimulation hypersensitivity) as well as reduced variability across electrical stimulation thresholds. The results suggest that a major contribution to temporal integration occurs in inferior colliculus or higher. In addition, the results suggest that the reduction in temporal integration that follows hearing impairment is a peripherally-induced, central effect.
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Affiliation(s)
- G M Gerken
- Department of Otorhinolaryngology, University of Texas Southwestern Medical Center, Dallas
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Abstract
Thresholds of neurons to sounds were compared as a function of central auditory structure [ventral cochlear nucleus (VCN), dorsal cochlear nucleus (DCN), and inferior colliculus (IC)] in young and middle-aged C57BL/6J mice (multiple- and single-unit recordings) and in young and old CBA/J mice (single-unit recordings). Middle-aged C57 mice show progressive loss of sensitivity to high frequencies and noise due to cochlear pathology; CBA mice show little loss of sensitivity through most of their lifespan. Multiple-unit threshold curves (MTCs) for tones indicated that neurons in the C57 VCN suffered a greater degree of age-related loss of sensitivity than neurons in the IC (from an earlier study). Furthermore, whereas the low frequency portions of MTCs in IC neurons in high frequency tonotopic regions typically become 'sensitized' in middle-aged C57 mice (i.e., lower thresholds than young mice), such was not the case for VCN neurons. In contrast to VCN neurons, MTCs of the population of DCN neurons studied were statistically indistinguishable from those of the IC. Measurements of single-unit response areas in C57 mice corroborated the MTCs. In CBA mice, little effect of age was found in comparing single-unit response areas of young and old mice. The findings indicate that sensorineural impairment in middle-aged C57 mice is accompanied by threshold changes that are more severe in the VCN than in the IC or DCN. Because the VCN and DCN are believed to play different roles in hearing, the functions they support should, likewise, be affected to different extents by age-related hearing loss.
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Affiliation(s)
- J F Willott
- Department of Psychology, Northern Illinois University, DeKalb 60115
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Abstract
The cardioarrhythmogenic potential of epileptic foci induced at mesencephalic and rhombencephalic levels was analyzed in hemispherectomized rats. Topical application of penicillin-G onto the mesencephalic quadrigeminal lamina or onto the fourth ventricle induced paroxysmal activity at the mesencephalic or bulbar neurone level. At the mesencephalic levels, the paroxysmal activity was characterized by a significant increase in the spontaneous frequency of the neurones, with the appearance of multiunit activity and rhythmical outbursts. The simultaneous recording of myocardial electrical activity and blood pressure showed that the paroxysmal activity triggered short-latency sinus bradyarrhythmias with wandering of the sinus pacemaker, the appearance of biphasic or negative P waves, some premature ventricular contractions and non-significant reduction of systolic and diastolic pressures. When the paroxysmal activity stopped, the cardiac rhythm and blood pressure returned to basal values. At the bulbar level, the paroxysmal activity appeared with longer latency and usually the rhythmical outbursts were not observed. Following bulbar paroxysmal activity only short-lasting episodes of sinus bradyarrhythmias appeared. Midcollicular transection eliminated paroxysmal activity at the bulbar level, and blood pressure and cardiac rhythm resumed basal values. After transection, an additional application of convulsant drug (penicillin-G or pentylenetetrazole) onto the fourth ventricle did not induce the reappearance of paroxysmal activity and the consequent cardiovascular alterations. The results showed the existence of a cardioarrhythmogenic trigger localized at the mesencephalic level which spreads paroxysmal activity upwards. A hypothesis to explain the appearance of fetal haemodynamic modifications and life-threatening arrhythmias has been proposed.
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Affiliation(s)
- O Mameli
- Institute of Human Physiology, University of Sassari, Italy
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Abstract
Recordings were made in vitro from cochlear nuclei of Gunn rats, a strain with a recessive mutation that predisposes rats to hyperbilirubinemia at birth. Delays between shocks to the auditory nerve and earliest synaptic responses of the cochlear nuclear neurons were on average longer in Gunn rats than in heterozygotes. Injections of sulfonamide further increased average synaptic delays in jaundiced rats. Responses to injected current in rats were like those in mice.
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Affiliation(s)
- S Zhang
- Department of Neurophysiology, University of Wisconsin, Madison 53706
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Abstract
This study examined the involvement of caudal brainstem projections of the hypothalamic paraventricular nucleus (PVN) in the medial hypothalamic (MH) hyperphagia-obesity syndrome. Experiment 1 demonstrated that a unilateral parasagittal knife cut in the MH combined with a contralateral coronal knife cut in either the ventrolateral pons (vP) or ventrolateral medulla (vM) significantly increased food intake and body weight in adult female rats. Overeating and overweight were also produced by a unilateral MH knife cut combined with a contralateral oblique cut under the nucleus of the solitary tract and dorsal motor nucleus of the vagus complex (NST/DX). In contrast, an MH cut x dorsolateral medullary cut combination did not increase food intake or body weight compared to a MH cut alone or sham surgery. Experiment 2 demonstrated that the hyperphagia/obesity effect of MH x vP knife cuts was comparable to that obtained with bilateral PVN lesions, but less than that produced by bilateral MH knife cuts. Bilateral vP cuts also increased body weight but the effect was less than that obtained with the other experimental treatments. Feeding the rats a high-fat diet rather than chow potentiated the hyperphagia and obesity syndromes produced by the various lesion conditions. Taken together, these findings suggest that the medial hypothalamic hyperphagia and obesity syndrome is due, in part, to damage to PVN projections to the caudal brainstem, the NST/DX complex in particular. The functional significance of this PVN-hindbrain "feeding" pathway and the identity of extra-PVN components of the hyperphagia-obesity syndrome remain to be established.
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Affiliation(s)
- A L Kirchgessner
- Health Science Center, Brooklyn State University of New York 11203
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Abstract
The author reports findings from recent psychophysiological and biochemical research on Vietnam combat veterans with chronic posttraumatic stress disorder. Applying these data and the analogy of the known functional and structural defects in the peripheral (cranial) sensory system consequent to high-intensity stimulation, he hypothesizes that cortical neuronal and synaptic changes occur in posttraumatic stress disorder as the consequence of excessive and prolonged sensitizing stimulation leading to depression of habituating learning. He postulates that the "constant" symptoms of the disorder are due to the changes in the agonistic neuronal system which impair cortical control of hindbrain structures concerned with aggressive expression and the sleep-dream cycle.
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Abstract
We report a case of Listeria rhombencephalitis in a previously healthy 60-year-old man. Listeria rhombencephalitis is a rare but well-defined clinical syndrome of lower brain-stem involvement caused by Listeria monocytogenes. Contrary to other listerioses, rhombencephalitis has been mainly observed in patients without predisposing conditions. In our case, however, findings of a detailed immunologic study, performed three months and one year, respectively, after clinical onset of Listeria rhombencephalitis manifestations, showed a transient cellular immunity defect, not associated with any other apparent disease.
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