Journal fur Hirnforschung最新文献_第4页

Validation of a four-vessel occlusion model for transient global cerebral ischemia in dogs. 犬短暂性全脑缺血四血管闭塞模型的验证。

Journal fur Hirnforschung Pub Date : 1999-01-01

M Pomfy, J Franko

{"title":"Validation of a four-vessel occlusion model for transient global cerebral ischemia in dogs.","authors":"M Pomfy, J Franko","doi":"","DOIUrl":"","url":null,"abstract":"A new model of transient global cerebral ischemia in dogs with minimal measures of intervention is described together with a simple scale for evaluation of functional outcome. During pentobarbital anesthesia, a global cerebral ischemia lasting seven minutes was induced by a four-vessel occlusion and a controlled systemic hypotension. The reperfusion phase begun after removal of arterial clamps, and the animals were sacrificed by perfusion fixation 24 hours latter. The efficiency of controlled systemic hypotension in diminishing collateral blood flow was validated in two experimental groups with different cerebral filling pressure (CFP). Severe ischemia group (CFP 1.0-1.5 kPa) underwent near-complete ischemia as indicated by rCBF, electroencephalography, and histologically documented ischemic neuronal changes. Mild ischemia group (CFP 2.5-3 kPa) animals experienced reduction in cerebral blood flow well above the ischemic threshold, had better functional outcome as well as no ischemic neuronal changes on light microscopy. This model consistently produces global cerebral ischemia in dogs with minimal surgical intervention and pharmacological support, and without intracranial hypertension, cardiac arrest or asphyxia. We recommend this model for outcome-oriented studies of complete forebrain ischemia in dogs.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 4","pages":"465-71"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21686406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrastructural study of the effects of 6-hydroxydopamine on the sinuatrial and atrioventricular nodes of the heart of the monkey (Macaca fascicularis). 6-羟多巴胺对猕猴心脏窦房结和房室结影响的超微结构研究。

Journal fur Hirnforschung Pub Date : 1999-01-01

M M Aye, G Singh, S S Tay

{"title":"Ultrastructural study of the effects of 6-hydroxydopamine on the sinuatrial and atrioventricular nodes of the heart of the monkey (Macaca fascicularis).","authors":"M M Aye, G Singh, S S Tay","doi":"","DOIUrl":"","url":null,"abstract":"The present study examined the ultrastructural changes in the sinuatrial and atrioventricular nodes of the heart of the monkey (Macaca fascicularis) after 6-hydroxydopamine (6-OHDA) at survival times of 1, 3, 5, 7 and 14 days. Changes ranged from dissolution of the cytoplasm to amorphous appearance and darkening of the nodal cells. Initially, the ultrastructural changes were quite similar in both sinuatrial (SA) and atrioventricular (AV) nodal cells but in the later stage, especially at fourteen days, affected SA nodal cells showed empty-looking appearance while affected AV nodal cells displayed a darkened appearance. The cardiac neurons also showed ultrastructural changes such as diffuse accumulation of glycogen particles, distended cisternae of the rough endoplasmic reticulum and increased lipofuscin granules. Some of the vacuolated axonal profiles containing large dense-cored vesicles were in close association with the somata of the cardiac neurons. There were also changes in the non-neuronal cells such as darkening and vacuolation of the cells capping the neurons. Macrophages and Schwann cells were activated to engulf the degenerating nodal cells and axonal profiles. The ultrastructural changes in the nodal cells and the cardiac neurons reflect a disturbance in the cell metabolism presumably brought about by the impairment of the sympathetic nervous system.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 4","pages":"503-11"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21686996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The activity of a transient potassium current in retinal glial (Müller) cells depends on extracellular calcium. 视网膜胶质细胞(m<s:1> ller)中瞬时钾电流的活性取决于细胞外钙。

Journal fur Hirnforschung Pub Date : 1999-01-01

A Bringmann, S Schopf, F Faude, S N Skatchkov, V Enzmann, A Reichenbach

{"title":"The activity of a transient potassium current in retinal glial (Müller) cells depends on extracellular calcium.","authors":"A Bringmann, S Schopf, F Faude, S N Skatchkov, V Enzmann, A Reichenbach","doi":"","DOIUrl":"","url":null,"abstract":"The modulating effects of varying extracellular concentrations of Ca2+ ([Ca2+]e) and of other divalent cations on the fast transient (A-type) K+ current (I(A)) of freshly isolated Muller glial cells from rabbit and human retinae were studied with the whole-cell patch-clamp method. The I(A) of Miller cells was voltage-independently blocked by extracellular 4-aminopyridine (4AP) with a 50 % reduction achieved at 0.94 mM 4AP. The I(A) amplitude was elevated by increased extracellular [K+]. Elevation of the [Ca2+]e had three effects on the glial I(A): (i) it concentration-dependently shifted both the activation and inactivation curves towards less negative membrane potentials, (ii) it increased the peak current amplitude, and (iii) it slowed down the activation and inactivation kinetics. Particularly at depolarized membrane potentials, the I(A) was enlarged and broadened when the [Ca2+]e was increased. Various divalent cations also exerted these effects, although at different concentrations. While Zn2+, Cd2+, Cu2+ and Pb2+ modulated the I(A) in the micromolar range, Mg2+ and Ba2+ had effects in the millimolar range. Extracellular acidification produced a positive shift in the voltage dependence of I(A) gating. However, alterations of the extracellular pH did not abolish the Ca2+ effects on I(A); this indicates that protons and Ca2+ ions mediate their effects on glial K(A) channels by different mechanisms or binding sites, respectively. Physiological (i.e., activity-dependent) changes of the extracellular concentration of divalent cations and of the extracellular pH should influence the retinal excitability via modulation of glial K+ currents. The activation of glial I(A) by divalent cations at depolarized voltages supports a repolarization and, therefore, the maintainance of a hyperpolarized glial membrane potential during periods of increased neuronal activity.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 4","pages":"539-50"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"21687000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of chloroquine on the pineal gland of postnatal rats. 氯喹对出生后大鼠松果体的影响。

Journal fur Hirnforschung Pub Date : 1998-01-01

C Kaur

{"title":"Effects of chloroquine on the pineal gland of postnatal rats.","authors":"C Kaur","doi":"","DOIUrl":"","url":null,"abstract":"1-day old postnatal rats were given daily intraperitoneal injections of chloroquine and sacrificed at various time intervals thereafter. In rats killed at 7 and 14 days of age a large number of cytoplasmic lamellar bodies were induced in the pinealocytes. The macrophages/microglia among the pinealocytes showed the presence of large dense bodies in their cytoplasm. In chloroquine injected rats killed at 21 days of age, the lamellar bodies had vanished. The macrophages/microglia were comparable to those in the control animals. Cytoplasmic lamellar bodies were not observed in the pinealocytes of the control rats in any age group and in rats killed at 2 and 4 days of age following chloroquine injections. The pineal macrophages/microglia in these rats showed the presence of only some small dense granules in their cytoplasm. The immunoreactivity of the macrophages/microglia with OX-42, OX-18, OX-6 and ED1 which detect the complement-type 3 receptors, major histocompatibility complex class I and class II antigens and monocyte/macrophage antigens respectively was comparable in chloroquine injected and control rats. The labelling of the macrophages/microglia with rhodamine isothiocyanate (RhIC) in 7 days old chloroquine injected rats was also comparable to the labelling of cells in the corresponding control rats. It is concluded from this study that although repeated chloroquine administration induces acute structural alteration of the pinealocytes and macrophages/microglia in the pineal gland, its effects are reversible since the cells regained their normal ultrastructural features following discontinuation of the drug. The immune functions and phagocytic activity of the macrophages/microglia shown by their immunoreactivity with various antibodies and RhIC labelling respectively are not altered by chloroquine.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 1","pages":"87-94"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20589895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Journal fur Hirnforschung Pub Date : 1998-01-01

D R Thal, W Härtig, R Schober

{"title":"Stage-correlated distribution of type 1 and 2 dystrophic neurites in cortical and hippocampal plaques in Alzheimer's disease.","authors":"D R Thal, W Härtig, R Schober","doi":"","DOIUrl":"","url":null,"abstract":"Two types of dystrophic neurites have been described in neuritic plaques in Alzheimer's disease (AD). Type 1 dystrophic neurites display tau-positive paired helical filaments (PHF) while those of type 2 are swollen and positive for both amyloid precursor protein and Chromogranin A. To determine the role of these two types of dystrophic neurites in the development of neuritic plaques, we examined their distribution in CA 1, CA 4, the entorhinal and the temporal cortex throughout all Braak-stages. Fourty cases with AD-related neurofibrillary changes were evaluated semi-quantitatively. The frequency of neuritic plaques displaying both types of dystrophic neurites seemed to increase from stage I to stage IV and to remain stable or slightly decrease in later stages. Staining combinations detecting type 1 (Gallyas, immunohistochemistry against hyperphosphorylated tau-protein) and type 2 dystrophic neurites simultaneously (immunohistochemistry against the amyloid precursor protein or Chromogranin A) showed coexpression of the type 1 and type 2 pattern in single neurites of neuritic plaques. In the entorhinal and temporal cortex, occasional neuritic plaques displayed tau-immunopositive changes in the absence of swollen type 2 neurites. Since amyloid precursor protein is expressed in distal ends of neurites after various brain lesions we suggest that amyloid precursor protein-positive neurites in neuritic plaques indicate dysfunctional axonal transport due to type 1 neurofibrillary changes.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 2","pages":"175-81"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20897233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Ultrastructural localization of thiamine pyrophosphatase in plasma membranes of brain phagocytes long time after cardiac arrest. 心脏骤停后长时间脑吞噬细胞细胞膜中硫胺素焦磷酸酶的超微结构定位。

Journal fur Hirnforschung Pub Date : 1998-01-01

M Walski, B Gajkowska

引用次数: 0

Immunoreactivity to synaptosomal-associated protein-25 in developing rat retinas: effects of a glutamate agonist and retinal transplantation to a host brain. 发育中的大鼠视网膜对突触体相关蛋白-25的免疫反应性:谷氨酸激动剂和视网膜移植到宿主脑的作用。

Journal fur Hirnforschung Pub Date : 1998-01-01

S T Chen, L J Garey, L S Jen

{"title":"Immunoreactivity to synaptosomal-associated protein-25 in developing rat retinas: effects of a glutamate agonist and retinal transplantation to a host brain.","authors":"S T Chen, L J Garey, L S Jen","doi":"","DOIUrl":"","url":null,"abstract":"In the postnatal rat retina immunoreactivity to synaptosomal-associated protein-25 (SNAP-25) was expressed primarily in the photoreceptors, inner and outer plexiform layers, and optic nerve fibres in a highly specific and age related manner. Of special interest are observations of characteristic changes of intracellular immunostaining in photoreceptors and distinct immunoreactive sublaminae in the inner plexiform layer during early postnatal stages. The overall pattern of immunoreactivity in the photoreceptor and plexiform layers remained unchanged after neonatal intravitreal injection of the glutamate agonist 2-amino-4-phosphonobutyric acid or optic tract lesion, and after adult intraorbital optic nerve section. However, a significant reduction in immunostaining in the inner plexiform and optic nerve fibre layers was observed several weeks after transplantation of the retina to a neonatal host brain. These results provide new insights into the role of SNAP-25 in membrane remodelling in relation to specific cell types and functions, and into intraretinal regulatory mechanisms that seem to be independent of the levels of glutamate and the influence of retinal ganglion cells.","PeriodicalId":14790,"journal":{"name":"Journal fur Hirnforschung","volume":"39 2","pages":"253-62"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20898367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Distribution of SPR-like immunoreactivity in the medullary visceral zone of the rat and changes following acute myocardial ischemia induced by intravenous injection of vasopressin. 静脉注射加压素急性心肌缺血后大鼠髓质内脏区spr样免疫反应性的分布及变化。

Journal fur Hirnforschung Pub Date : 1998-01-01

W Gao, H Liu, Z Rao, G Ju

引用次数: 0

Complementary distributions of calbindin, parvalbumin and calretinin in the cerebellar vermis of the adult cat. 钙结合蛋白、小白蛋白和钙凝蛋白在成年猫小脑蚓部的互补分布。

Journal fur Hirnforschung Pub Date : 1998-01-01

X X Yan, L J Garey

引用次数: 0

Axonal ramification of neurones in the nuclei raphe pallidus and obscurus projecting to the cerebellar paramedian lobule. A fluorescent double labelling study in the rabbit. 投射到小脑旁小叶的苍白核和隐核内神经元的轴突分支。兔荧光双重标记的研究。

Journal fur Hirnforschung Pub Date : 1998-01-01

E Sikora

引用次数: 0