Clinical Neuroscience

[HISTOCHEMISTRY OF THE EXTRACELLULAR MATRIX IN THE SNAIL CENTRAL NERVOUS SYSTEM]

SERFŐZŐ Zoltán, ELEKES Károly

MARCH 20, 2007

Clinical Neuroscience - 2007;60(03-04)

[Even tough the central nervous system (CNS) of gastropods has long been used as a model for studying different neuronal networks underlying behaviors, there is only little information on the molecular components of the extracellular matrix (ECM) of the nervous tissue. Therefore, the aim of the present study was to identify some of the ECM molecules by acid-base histochemistry. Staining with alcian blue at strong acidic pH, and with acridine orange at different pH and salt concentrations was carried out on cryostat sections taken from CNS preparations of adult specimens of the terrestrial snail, Helix pomatia, and the aquatic species, Lymnaea stagnalis, in order to visualize mild (carboxyl) and strong (sulphate) acidic groups, which are characteristic for different glucosaminoglycans. According to our findings, sulphated proteoglycans were abundant in the periganglionic sheath of both species, and they also occurred in the neuropil of Helix, whereas they were absent in Lymnaea. The interperikaryonal space contained mainly carboxyl residues, which might refer to the presence of hyaluronic acid. It is concluded that the ECM of the snail CNS, similarly to that in vertebrates, is partly composed of polymer macromolecules of different chemical properties. It is suggested that adaptation to environmental conditions and/or altered neuronal plasticity are responsible for the differences found in chemical characters of the ECM molecules between the two snail species.]

COMMENTS

0 comments

Further articles in this publication

Clinical Neuroscience

[PROTECTIVE ACTION OF SNAKE VENOM NAJA NAJA OXIANA AT SPINAL CORD HEMISECTION]

ABRAHAMYAN S. Silva, MELIKSETYAN B. Irina, CHAVUSHYAN A. Vergine, ALOYAN L. Mery, SARKISSIAN S. John

[Based on data accumulated regarding the neuroprotective action of Proline-Rich-Peptide-1 (PRP-1, a fragment of neurophysin vasopressin associated hypothalamic glycoprotein consisting of 15 amino acid residues) on neurons survival and axons regeneration and taking into the account that LVV-Hemorphin-7 (LVV-H7, an opioid peptide, widely distributed in different cell types of various tissues of intact rats, including those of the nervous and immune systems) derived from the proteolitic processing of hemoglobin in response to adverse environmental and physiological conditions, possesses the anti-stressor properties, we used histochemistry, immunohistochemistry and electrophysiology to investigate the putative neuroprotective action of Central Asian Cobra Naja naja oxiana snake venom (NOX) on trauma-injured rats. ABC immunohistochemical method and histochemical method on detection of Ca2+- dependent acid phosphatase activity were used for the morpho-functional study. By recording the electrical activity of the signals from the single neurons in and below the SC injury place, NOX venom has been shown to result in the complete restoration of hypothalamic-spinal projections originated from ipsi- and contra-lateral PVN and SON to neurons of SC lumbar part. NOX prevented the scar formation, well observed two months after SC injury in the control rats, resulted in the regeneration of nerve fibers growing through the trauma region, survival of the PRP-1- and LVV-H7-immunoreactive (Ir) neurons, and increase of the PRP-1- and LVV-H7-Ir nerve fibers and astrocytes in the SC lesion region. NOX was suggested to exert the neuroprotective effect, involving the PRP-1 and LVV-H7 in the underlying mechanism of neuronal recovery.]

Clinical Neuroscience

[CENTRAL ATRIAL NATRIURETIC PEPTIDE IN DEHYDRATION]

BAHNER Udo, GEIGER Helmut, PALKOVITS Miklós, LENKEI Zsolt, LUFT C. Friedrich, HEIDLAND August

[To test the effect of dehydration on brain atrial natriuretic peptide (ANP) concentrations in areas important to salt appetite, water balance and cardiovascular regulation, we subjected rats to dehydration and rehydration and measured ANP concentration in 18 brain areas, as well as all relevant peripheral parameters. Water deprivation decreased body weight, blood pressure, urine volume, and plasma ANP, while it increased urine and plasma osmolality, angiotensin II, and vasopressin. ANP greatly increased in 17 and 18 brain areas (all cut cerebral cortex) by 24 h. Rehydration for 12 h corrected all changes evoked by dehydration, including elevated ANP levels in brain. We conclude that chronic dehydration results in increased ANP in brain areas important to salt appetite and water balance. These results support a role for ANP as a neuroregulatory substance that participates in salt and water balance.]

Clinical Neuroscience

[OXYGEN-GLUCOSE DEPRIVATION-INDUCED CHANGES IN ORGANOTYPIC CULTURES OF THE RAT HIPPOCAMPUS]

BALI Balázs, NAGY Zoltán, KOVÁCS J. Krisztina

[Introduction - (-)Deprenyl is an irreversible inhibitor of type B monoamine oxidase (MAO-B), which is now used for treatment of Parkinson’s or Alzheimer’s diseases. Evidence suggests that the neuroprotective effect of deprenyl may not be related exclusively to the inhibition of the enzyme MAO-B. Methods - To test the impact of deprenyl on ischemiainduced changes in vitro, we followed the time course of propidium iodide (PI) uptake as an indicator of neuronal cell death as well as the expression of apoptotic factors in organotypic hippocampal slice cultures exposed to oxygen- glucose deprivation (OGD) for 45 min. Results - The first signs of neuronal death were detected 2 hours after OGD and were extended to all subfields of the hippocampus by 24 hours post-injury. Presence of deprenyl (10-9 M) significantly delayed the cell death induced by the insult. Exposure of control cultures to deprenyl significantly increased the abundance of Bcl-2 and Bcl-xl mRNAs as revealed by RT-PCR. OGD resulted in an elevation of anti-apoptotic factors, while the expression of pro-apoptotic bax remained unchanged. Conclusion - These data suggest that deprenyl is neuroprotective in an in vitro model of ischemia. Although deprenyl upregulates the expression of Bcl-2 under basal conditions, its effect on anti-apoptotic factors is not significantly manifested during OGD.]

Clinical Neuroscience

[EFFECT OF LOCAL (INTRACEREBRAL AND INTRACEREBROVENTRICULAR) ADMINISTRATION OF TYROSINE HYDROXYLASE INHIBITOR ON THE NEUROENDOCRINE DOPAMINERGIC NEURONS AND PROLACTIN RELEASE]

BODNÁR Ibolya, HECHTL Dániel, SZÉKÁCS Dániel, OLÁH Márk, NAGY M. György

[Background and purpose - Hypothalamic dopamine (DA), the physiological regulator of pituitary prolactin (PRL) secretion, is synthesized in the neuroendocrine DAergic neurons that projects to the median eminence and the neurointermediate lobe of the pituitary gland. The rate-limiting step of DA biosynthesis is catalyzed by the phosphorylated, therefore activated, tyrosine hydroxylase (TH) that produces L-3,4-dihydroxy- phenylalanine from tyrosine. The aims of our present study were to investigate 1. the effect of local inhibition of the DA biosynthesis in the hypothalamic arcuate nucleus on PRL release, and to get 2. some information whether the phosphorylated TH is the target of enzyme inhibition or not. Methods - A TH inhibitor, α-methyl-p-tyrosine was injected either intracerebro-ventricularly or into the arcuate nucleus of freely moving rats and plasma PRL concentration was measured. Immunohistochemistry, using antibodies raised against to native as well as phosphorylated TH were used to compare their distributions in the arcuate nucleus-median eminence region. Results - Intracerebro-ventricular administration of α-methyl-p-tyrosine has no effect, unlike the intra-arcuatus injection of enzyme inhibitor resulted in a slight but significant elevation in plasma PRL. Parallel with this, the level of DA and DOPAC were reduced in the neurointermediate lobe while no change in norepinephrine concentration can be detected indicating a reduced biosynthesis of dopamine following TH inhibition. On the other hand, systematic application of the α-methyl-p-tyrosine that inhibits TH activity located in DA terminals of the median eminence and the neurointermediate lobe, resulted in the most significant elevation of PRL. Conclusion - Our results suggest that α-methyl-p-tyrosine administered close to the neuroendocrine DAergic neurons was able to inhibit only a small proportion of the TH. Moreover, it also indicate that the majority of the activated TH can be found in the axon terminals of DAergic neurons, therefore, the DA released into the pituitary portal circulation is synthesized at this site.]

Clinical Neuroscience

[USING BRAIN SLICE CULTURES OF MOUSE BRAIN TO ASSESS THE EFFECT OF GROWTH FACTORS ON DIFFERENTIATION OF BONE MARROW DERIVED STEM CELLS]

BRATINCSÁK András, LONYAI Anna, SHAHAR Tal, HANSEN Arne, TÓTH E. Zsuzsanna, MEZEY Éva

[Bone marrow derived stem cells (BMDSCs) have been reported to form neurons and supportive cells in the brain. We describe a technique that combines the simplicity of in vitro studies with many of the advantages of in vivo experiments. We cultured mouse brain slices, deposited GFPtagged BMDSCs evenly distributed on their surfaces, and then added test factors to the culture medium. Addition of both SDF-1 and EGF resulted in morphological changes of BMDSC and in the induction of islet-1, a marker of neuroepithelial progenitors. We conclude that organotypic tissue culture (OTC) may allow us to detect the effects of exogenous factors on the differentiation of BMDSCs (or any other type of stem cells) in an environment that may resemble the CNS after brain injury. Once such factors have been identified they could be evaluated for tissue regeneration in more complex, whole animal models.]

All articles in the issue

Related contents

Clinical Neuroscience

[Prognostic significance of invasion in glioblastoma]

SZIVÓS László, VIRGA József, HORTOBÁGYI Tibor, ZAHUCZKY Gábor, URAY Iván, JENEI Adrienn, BOGNÁR László, ÁRKOSY Péter, KLEKNER Álmos

[Glioblastoma is the most common malignant CNS tumor, its surgical removal is hindered by the tumors invasive nature, while current anti-tumor therapies show limited effectiveness – mean overall survival is 16-24 months. Some patients show minimal response towards standard oncotherapy, however there are no routinely available prognostic and predictive markers in clinical practice to identify the background of mentioned differences in prognosis. This research aims to identify the prognostic significance of invasion-related extracellular (ECM) components. Patient groups with different prognoses were created (OS: group A <16 months, group B > 16 months), and internationally recognized prognostic markers (IDH1 mutation and MGMT promoter hyper-methylation) were tested in the flash-frozen tumor samples. Furthermore, the mRNA levels of 46 invasion-related ECM molecules were measured. Clinical data of the patients who have been operated on at the University of Debrecen Clinical Center Department of Neurosurgery and treated at the Department of Clinical Oncology showed no significant differences except for survival data (OS and PFS), and reoperation rate. All samples were IDH wild type. MGMT promoter hypermethylation rate showed significant differences (28.6% vs 68.8%). The expressional pattern of the invasion-related ECM molecules, i.e. the invasion spectrum also showed major differences, integrin β2, cadherin-12, FLT4/VEGFR-3 and versican molecules having signficantly different mRNA levels. The accuracy of the inivasion spectrum was tested by statistical classifier, 83.3% of the samples was sorted correctly, PPV was 0.93. The difference found in the reoperation rate when comparing different prognostic groups aligns with literature data. MGMG promoter region methylation data in Hungarian samples has not been published yet, and further confirming current knowledge urges the implementation of MGMT promoter analysis in clinical practice. Studying the invasion spectrum provides extra information on tumors, as a prognostic marker it helps recognizing more aggressive tumors, and calls attention to the necessity of using anti-invasive agents in GBM therapies in the future.]

Lege Artis Medicinae

[Tuberculous meningoencephalitis in a toddler child]

REISZ Zita, GÁL Péter, TAJTI Zsanett, TERHES Gabriella, URBÁN Edit, KISS Ildikó, BARZÓ Pál, KIS Dávid, SENONER Zsuzsanna, SZABÓ Nóra, SZAPPANOS Norbert, TISZLAVICZ László

[INTRODUCTION - Central nervous system complications occur in 1% of patients with Mycobacterium tuberculosis infection, but the mortality is very high, about 50 percent. CASE REPORT - A 1-year-old child in tenebrous condition was admitted to the hospital with suspicion of meningitis. MRI detected disseminated encephalitis and dilated ventricles. Examination of the serum and cerebrospinal fluid didn’t bring any results. The microscopic examination of the brain biopsy raised the possibility of tuberculous meningoencephalitis, and the culture and PCR from the brain tissue revealed meningoencephalitis caused by Mycobacterium tuberculosis Beijing. DISCUSSION - Tuberculous meningitis is a very rare, but severe consequence of extrapulmonary tuberculosis. Due to the high mortality, early diagnosis and whenever suspected, the use of empiric antituberculotic therapy are the only chances of recovery.]

Lege Artis Medicinae

[Central nervous system hemorrhage in Wegener’s granulomatosis]

SZABOLCSI Orsolya, SZÁNTÓ Antónia, ZEHER Margit

[In our case a 41-year-old man with following symptoms: non-productive coughing, fever, difficulty in breathing and weight loss was examined in February 2007, and on the basis of chest X-ray, CT and bronchoscopy, the possibility of neoplasm or tuberculosis cropped up. After the applied therapy (steroid, antibiotics, tuberculostatic drugs) the symptoms became more severe, i.e. hematuria and epistaxis were manifested. A tissue biopsy was carried out during bronchoscopy and the histological examination revealed granulomatous reaction. Meanwhile, the presence of c-ANCA was proved, and Wegener’s granulomatosis (WG) was diagnosed. In March 2007, sudden somnolence and left side hemiplegia developed, and a large haemorrhage was recognised on CT scan in the right fronto-temporal region, with regard to the haemorrhage, the patient had to undergo a neurosurgical operation. We started to treat him in April 2007 by intravenous steroid and 600 mg of cyclophosphamide (Cyc), and he regained the ability to walk again. In October 2007, the Cyc treatment was terminated, and we administered a maintenance therapy with methotrexat. During the regular medical check-up, a chest X-ray indicated a second attack in March 2008, which was confirmed by the chest CT, the clinical symptoms, increased anti-PR3 levels and c-ANCA positivity as well. The flair of the disease was established. Consequently, in April 2008 we decided on plasmapheresis therapy synchronised with Cyc. After that, we started an azathioprine maintenance therapy and he got rid of all the activation symptoms. We can say that with the adequate therapy started in good time and with the regular medical check up of the patient a good result can be achieved. It is true even in the case of WG disease associated by severe complication, for example central nervous hemorrhage.]

Lege Artis Medicinae

[PLEIOTROPIC FUNCTIONS OF ERYTHROPOIETIN]

NAGY Judit, KISS István

[Erythropoietin produced by the foetal liver and the adult kidney is the major stimulator of erythropoiesis. Erythropoietin production is regulated by hypoxic activation of erythropoietin gene transcription. Recently, new sites of erythropoietin production have been found mainly in the central nervous system and in the cardiovascular system. These tissues have a paracrine and/or autocrine system of erythopoietin. The pleiotropic function of erythropoietin in these systems is tissue and cell protection by several mechanisms including inhibition of apoptosis, attenuation of ischaemic or reperfusion injury, anti-inflammatory and antioxidative effects. Furthermore, it promotes vascular recovery and enhances neoangiogenesis. In vivo and in vitro studies have proved that systemically administered human erythropoietin can also provide tissue protection. However, adverse effects of erythropoietin treatment such as hypertension, hyperviscosity and thrombosis may override the beneficial effect of systemic erythropoietin treatment. There are preliminary data that erythropoietin analogues, e.g., asyaloerythropoietin or carbamylated erythropoietin can provide tissue protection without stimulating erythropoiesis.]

Clinical Neuroscience

[Extracellular matrix of intracerebral tumors with different invasion activity]

KLEKNER Álmos, VARGA Imre, BOGNÁR László, HUTÓCZKI Gábor, KENYERES Annamária, TÓTH Judit, HANZÉLY Zoltán, SCHOLTZ Beáta

[Objectives - Ineffective surgical and radiotherapy of glioblastoma is mainly due to its intensive infiltrating behavior. Contrarily, brain metastases of anaplastic carcinomas are well-circumscribed intracerebral lesions that can be easily exstirpated in most cases. The molecules of the extracellular matrix (ECM) play a pivotal role in the peritumoral infiltration. In this study the mRNA expression of the ECM components was investigated in two types of intracerebral malignoma with different invasion activity. Our aim was to identify the ECM molecules that are responsible for the different intensity of peritumoral infiltration of tumors from different origin. Methods - The mRNA expression of twenty-three ECM molecules was determined by quantitative reverse transcriptase polymerase chain reaction. Four pieces of glioblastoma and four pieces of intracerebral lung adenocarcinoma metastasis from neurosurgical operation were investigated. Immunohistochemical investigations were performed in case of five molecules. Results - The mRNA expression of nine molecules (brevican, neurocan, neuroglycan-C, syndecan-1,2,4, tenascin-C, versican and matrix-metalloproteinase-[MMP]2) differed significantly by comparison of the two tumor types. By immunohistochemistry, neurocan, syndecan, versican and MMP-2 showed alteration in staining intensity according to the mRNA expression, while MMP-9 showed higher staining intensity in the metastatic tumor. Conclusions - The identified molecules can play an important role in the different infiltration activity of tumors from different origin. Thus these ECM-components could serve as targets for anti-invasion therapy in the future.]