Clinical Neuroscience

[SYNAPTIC CONNECTIONS OF GLUTAMATERGIC NERVE FIBRES IN THE RAT SUPRACHIASMATIC NUCLEUS]

KISS József, CSÁKI Ágnes, CSABA Zsolt, HALÁSZ Béla

MARCH 20, 2007

Clinical Neuroscience - 2007;60(03-04)

[Background and purpose - The hypothalamic suprachiasmatic nucleus functioning as the principal circadian pacemaker in mammals, has a rich glutamatergic innervation. Nothing is known about the terminations of the glutamatergic fibres. The aim of the present investigations was to study the relationship between glutamatergic axon terminals and vasoactive intestinal polypeptide (VIP), GABA and arginine-vasopressin (AVP) neurons in the cell group. Methods - Double label immunocytochemistry was used and the brain sections were examined under the electron microscope. Vesicular glutamate transporter type 2 was applied as marker of the glutamatergic elements. Results - Glutamatergic fibers were detected in synaptic contact with GABAergic, VIP- and AVP-positive neurons forming asymmetric type of synapses. Conclusion - The findings are the first data on the synaptic contacts of glutamatergic axon terminals with neurochemically identified neurons in the suprachiasmatic nucleus.]

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Clinical Neuroscience

[Editor’s note]

RAJNA Péter

Clinical Neuroscience

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

SERFŐZŐ Zoltán, ELEKES Károly

[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.]

Clinical Neuroscience

[THE GHRELIN SYSTEM: PHYSIOPATHOLOGICAL INVOLVEMENT IN THE CONTROL OF BODY GROWTH AND ENERGY METABOLISM]

JACQUES Epelbaum

[This short review will summarize some recent findings on the physiopathology of the endogenous ghrelin/obestatin system by focussing on experimental studies aiming at blocking the effects of endogenous ghrelin and clinical studies investigating genotype/phenotype correlations concerning the genes encoding for ghrelin and its cognate receptor.]

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

[IMMOBILIZATION INDUCED FOS EXPRESSION IN THE MEDIAL AND LATERAL HYPOTHALAMIC AREAS: A LIMITED RESPONSE OF HYPOCRETIN NEURONS]

KISS Alexander

[Induction of Fos, a proto-oncogene c-fos protein product, was immunohistochemically examined in the rat hypothalamic neurons 3 h after a single (1×120 min) or repeated (7×120 min) immobilization (IMO) stress. The aim of the present study was to reveal a possible parallelism in the cell activation between the medial and lateral hypothalamic neurons, especially between the stress responsive neurons in the hypothalamic paraventricular nucleus (PVN) and hypocretin (Hcrt) synthesizing neurons, i.e. suspected stress active neurons of the lateral hypothalamus. After IMO, the animals were perfused and their brains processed with immunohistochemistry for Fos or Fos/Hcrt proteins. Acute IMO elicited extensive Fos expression in both the examined areas. Excessive Fos expression was mainly seen in the PVN, while Hcrt neurons failed to show a broad response (appr. 5%) to single IMO. Clear occurrence of Fos signal was also seen in both hypothalamic areas of IMO-habituated rats. However, in these animals, in both areas examined, the number of Fos neurons was considerably suppressed, including the PVN. These results indicate that IMO is able to evoke a concurrent activation of Fos in many medial and lateral hypothalamic neurons. However, the scanty response of Hcrt neurons to acute IMO does not allow to assort them to a distinct IMO stress-responsive neuronal phenotypes of the brain.]

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[GLUTAMATERGIC PHENOTYPE OF HYPOTHALAMIC NEUROSECRETORY SYSTEMS: A NOVEL ASPECT OF CENTRAL NEUROENDOCRINE REGULATION]

HRABOVSZKY Erik, LIPOSITS Zsolt

[While three decades ago, the co-existence of classical neurotransmitters and peptide neuromodulators in a single neuronal cell was considered to be rather exceptional, the phenomenon that neurons have a complex transmitter phenotype now appears to be the general rule. Parvicellular and magnocellular neurosecretory systems consist of neuronal cells which are specialized in secreting peptide neurohormones into the blood-stream to regulate hypophyseal functions. This mini-review, dedicated to the memory of Mariann Fodor, summarizes the current knowledge about the classical neurotransmitter content of different hypothalamic neurosecretory systems, with a special focus on the occurrence and putative functions of glutamate in parvicellular and magnocellular neurosecretory cells.]

Clinical Neuroscience

Cyanocobalamin and cholecalciferol synergistically improve functional and histopathological nerve healing in experimental rat model

ALBAY Cem, ADANIR Oktay, AKKALP Kahraman Asli, DOGAN Burcu Vasfiye, GULAEC Akif Mehmet, BEYTEMUR Ozan

Introduction - Peripheral nerve injury (PNI) is a frequent problem among young adults. Hopefully, regeneration can occur in PNI unlike central nervous system. If nerve cut is complete, gold standard treatment is surgery, but incomplete cuts have been tried to be treated by medicines. The aim of the study was to evaluate and compare clinical and histopathological outcomes of independent treatment of each of Vitamin B12 (B12) and Vitamin D3 (D3) and their combination on sciatic nerve injury in an experimental rat model. Materials and methods - Experimental animal study was performed after the approval of BEH Ethics Committee No. 2015/10. 32 rats were grouped into four (n=8) according to treatment procedures, such as Group 1 (controls with no treatment), Group 2 (intraperitoneal 1 mg/kg/day B12), Group 3 (oral 3500 IU/kg/week D3), Group 4 (intraperitoneal 1 mg/kg/day B12+ oral 3500 IU/kg/week D3). Sciatic Functional Index (SFI) and histopathological analysis were performed. Results - SFIs of Group 2, 3, 4 were statistically significantly higher than controls. Group 2 and 3 were statistically not different, however Group 4 was statistically significantly higher than others according to SFI. Axonal degeneration (AD) in all treatment groups were statistically significantly lower than in Group 1. AD in Group 4 was significantly lower than in Group 2 and 3; there was no significant difference between Group 2 and 3. There was no significant difference between Group 1,2 and 3 in Axonolysis (A). But A of Group 4 was significantly very much lower than all others. Oedema- inflammation (OE-I) in all treatment groups were significantly lower than in Group 1; there was no significant difference between Group 2 and group 4. OE-I in Group 2 and 4 were significantly lower than in Group 3. There were no significant differences between Group 1, 2 and 3 in damage level scores; score of Group 4 was significantly lower than of Group 1. Conclusions - B12 and D3 were found effective with no statistically significant difference. But combined use of B12 and D3 improve nerve healing synergistically. We recommend combined use of B12 and D3 after PNI as soon as possible.

Hypertension and nephrology

[Association between cyclothymic affective temperament and hypertension]

NEMCSIK János, BATTA Dóra, KŐRÖSI Beáta, RIHMER Zoltán

[Affective temperaments (cyclothymic, hypertymic, depressive, anxious, irritable) are stable parts of personality and after adolescent only their minor changes are detectable. Their connections with psychopathology is well-described; depressive temperament plays role in major depression, cyclothymic temperament in bipolar II disorder, while hyperthymic temperament in bipolar I disorder. Moreover, scientific data of the last decade suggest, that affective temperaments are also associated with somatic diseases. Cyclothymic temperament is supposed to have the closest connection with hypertension. The prevalence of hypertension is higher parallel with the presence of dominant cyclothymic affective temperament and in this condition the frequency of cardiovascular complications in hypertensive patients was also described to be higher. In chronic hypertensive patients cyclothymic temperament score is positively associated with systolic blood pressure and in women with the earlier development of hypertension. The background of these associations is probably based on the more prevalent presence of common risk factors (smoking, obesity, alcoholism) with more pronounced cyclothymic temperament. The scientific importance of the research of the associations of personality traits including affective temperaments with somatic disorders can help in the identification of higher risk patient subgroups.]

Clinical Neuroscience

Isolated hypoglossal nerve palsy due to a jugular foramen schwannoma

ÖZTOP-CAKMAK Özgür, VANLI-YAVUZ Ebru, AYGÜN Serhat, BASTAN Birgül, EGEMEN Emrah, SOLAROGLU Ihsan, GURSOY-OZDEMIR Yesemin

Introduction – Although the involvement of the hypoglossal nerve together with other cranial nerves is common in several pathological conditions of the brain, particularly the brainstem, isolated hypoglossal nerve palsy is a rare condition and a diagnostic challenge. Case presentation – The presented patient arrived to the hospital with a history of slurred speech and an uncomfortable sensation on his tongue. Neurological examination showed left-sided hemiatrophy of the tongue with fasciculations and deviation towards the left side during protrusion. Based on the clinical and MRI findings, a diagnosis of hypoglossal nerve schwannoma was made. Discussion – Hypoglossal nerve palsy may arise from multiple causes such as trauma, infections, neoplasms, and endocrine, autoimmune and vascular pathologies. In our case, the isolated involvement of the hypoglossal nerve was at the skull base segment, where the damage to the hypoglossal nerve may occur mostly due to metastasis, nasopharyngeal carcinomas, nerve sheath tumors and glomus tumors. Conclusion – Because of the complexity of the region’s anatomy, the patient diagnosed with hypoglossal nerve schwannoma was referred for gamma knife radiosurgery.