Div

"Tokat Halk Edebiyatı Ürünlerinde Şamanizm Unsurları Son yıllarda edebiyatta Şamanist unsurlar, karşılaştırmalı edebiyatçıların dikkatinden kaçmıştır. Yine de Şamanizm unsurları hâlâ Türk edebiyatında çok önemli bir kavram olarak yer almaktadır. Özellikle halk edebiyatında olmak üzere, yazınsal modern Türk edebiyatında da sıkça mitolojik kültürümüzün izlerine rastlamaktayız, fakat bunları incelemede yetersiz kalmaktayız. Bu makalede, Tokat yöresinde varlığını devam ettiren veya Tokat’ta ortaya çıkan halk edebiyatı unsurları üzerinde Şamanist kavramların farklı yönleri üzerinde tek tek durulacak ve geçmişteki araştırmalarla karşılaştırılarak Tokat yöresinde halkın zihninde bugüne yansıyan tasarımları ortaya konulacaktır. Eskiden günümüze gelen temsillerde hangi tür semboller, hangi tür rolleri oynar; günümüzde oluşmuş semboller neden oluşmuştur ve fonksiyonları nedir, gibi sorulara da cevaplar arayacağız. Tüm bu değerlendirmeleri yaparken de ana kaynaklarımızı halk edebiyatı ürünleri oluşturacaktır."

Rett syndrome (RTT) is associated with mutations in the transcriptional repressor gene MeCP2. Although the clinical and neuropathological signs of RTT suggest disrupted synaptic function, the specific role of methyl-CpG binding protein 2 (MeCP2) in postmitotic ...

The development of the dendritic tree of a neuron is a complex process which is thought to be regulated strongly by signals from afferent fibers. In particular the synaptic activity of afferent fibers and activity-dependent signaling by neurotrophic factors are thought to affect dendritic growth. We have studied Purkinje cell dendritic arbor development in organotypic cultures under suppression of glutamate-mediated excitatory neurotransmission, achieved with multiple combinations of blockers of glutamate receptors. Despite the presence of either single receptor blockers or combinations of blockers predicted to fully suppress glutamate-mediated excitatory neurotransmission Purkinje cell dendritic arbors developed similar to those of control cultures. Furthermore, Purkinje cell dendritic arbors in organotypic cultures from brain-derived neurotrophic factor (BDNF) knockout mice or after pharmacological blockade of trk-receptors also developed in a way similar to control cultures. Our ...

We present a label-free in vitro method for testing the toxic potentials of chemical substances using primary neuronal cells. The cells were prepared from 16-day-old NMRI mouse embryos and cultured on silicon chips (www.bionas.de) under the influence of different parathion concentrations with sensors for respiration (Clark-type oxygen electrodes), acidification (pH-ISFETs) and cell adhesion (interdigitated electrode structures, IDES). After 12 days in vitro, the sensor readouts were simultaneously recorded for 350 min in the presence of parathion applying a serial 1:3 dilution. The parathion-dependent data was fitted by logistic functions. IC(50) values of approximately 105 μM, 65 μM, and 54 μM were found for respiration, acidification, and adhesion, respectively. An IC(50) value of approximately 36 μM was determined from the intracellular ATP-levels of cells, which were detected by an ATP-luminescence assay using micro-well plates. While the intracellular ATP level and cell adhesio...

... is involved in a number of central nervous system diseases, including stroke, head trauma (Arundine and Tymianski, 2004) and epilepsy (Wasterlain and Chen, 2008), while abnormal expression, function and regulation of NR may play a role in schizophrenia (Kristiansen et al ...

We have investigated the ability of certain dietary flavonoids, known to exert beneficial effects on the central nervous system, to affect neuronal apoptosis. We used cerebellar granule cells undergoing apoptosis due to potassium deprivation in a serum-free medium in either the absence or presence of the flavonoids genistein and daidzein, which are present in soy, and of catechin and epicatechin, which are present in cocoa. These compounds were used in a blood dietary concentration range. We found that genistein and daidzein, but not catechin and epicatechin, prevented apoptosis, with cell survival measured 24 h after the induction of apoptosis being higher than that of the same cells incubated in flavonoid free medium (80% and 40%, respectively); there was no effect in control cells. A detailed investigation of the effect of these compounds on certain mitochondrial events that occur in cells en route to apoptosis showed that genistein and daidzein prevented the impairment of glucose oxidation and mitochondrial coupling, reduced cytochrome c release, and prevented both impairment of the adenine nucleotide translocator and opening of the mitochondrial permeability transition pore. Interestingly, genistein and daidzein were found to reduce the levels of reactive oxygen species, which are elevated in cerebellar granule cell apoptosis. These findings strongly suggest that the prevention of apoptosis depends mainly on the antioxidant properties of genistein and daidzein. This could lead to the development of a flavonoid-based therapy in neuropathies.GEN and DZN reduce the level of ROS, the release of cytochrome c, the impairment of ANT, the opening of mPT and the apoptotic death in CGCs.

The Lewis(x) (Le(x)) epitope (Gal(beta1-4)[Fuc(alpha1-3)]GlcNAc-R) has been associated with the development of the central nervous system of diverse species including human and rodents. In this work, Le(x) has been found in the tetanus neurotoxin insensitive vesicle-associated membrane protein (TI-VAMP) compartment of rat hippocampus neurons in culture, at 7 days in vitro (DIV), when neurite extension is abundant. The TI-VAMP compartment is known to be associated with neurite outgrowth. Le(x) was found predominantly in neurites but also in somata and in growth cones. Abundant Le(x)-carrier glycoproteins specific to neurons have been identified at this stage of differentiation. At a later stage of differentiation, at 14 DIV, Le(x) appeared in extrasynaptic sites of GABAergic neurons, and in synaptic sites of glutamatergic neurons.

The current study revisited the question of whether there are brain mechanisms specific to divided attention that differ from those used in selective attention. Increased neuronal activity required to simultaneously process two stimulus dimensions as compared with each separate dimension has often been observed, but rarely has activity induced by a divided attention condition exceeded the sum of activity induced by the component tasks. Healthy participants performed a selective-divided attention paradigm while undergoing functional ...

While excitotoxicity is a major contributor to the pathophysiology of acute spinal injury, its time course and the extent of cell damage in relation to locomotor network activity remain unclear. We used two in vitro models, that is, the rat isolated spinal cord and spinal organotypic cultures, to explore the basic characteristics of excitotoxicity caused by transient application of the glutamate analogue kainate followed by washout and analysis 24 h later. Electrophysiological records showed that fictive locomotion was slowed down by 10 microM kainate (with no histological loss) and fully abolished by 50 microM, while disinhibited bursting with unchanged periodicity persisted. Kainate concentrations (> or =50 microM) larger than those necessary to irreversible suppress fictive locomotion could still elicit dose-dependent motoneuron pool depolarization, and dose-dependent neuronal loss in the grey matter, especially evident in central and dorsal areas. Motoneuron numbers were larg...

Synaptosomal associated protein of 25 kDa (SNAP-25) is a component of the soluble N-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) complex which plays a central role in synaptic vesicle exocytosis. We have previously demonstrated that adult rat hippocampal GABAergic synapses, both in culture and in brain, are virtually devoid of SNAP-25 immunoreactivity and are less sensitive to the action of botulinum toxin type A, which cleaves this SNARE protein [Neuron 41 (2004) 599]. In the present study, we extend our findings to the adult mouse hippocampus and we also provide demonstration that hippocampal inhibitory synapses lacking SNAP-25 labeling belong to parvalbumin-, calretinin- and cholecystokinin-positive interneurons. A partial colocalization between SNAP-25 and glutamic acid decarboxylase is instead detectable in developing mouse hippocampus at P0 and, at a lesser extent, at P5. In rat embryonic hippocampal cultures at early developmental stages, ...