bluuebunny/crossref_metadata_2025_split huggingface dataset:
AMPA and NMDA Glutamate Receptor Subunits in Midbrain Dopaminergic Neurons in the Squirrel Monkey: An Immunohistochemical andIn SituHybridization Study
Authors: Paquet Maryse , Tremblay Martine , Soghomonian Jean-Jacques , Smith Yoland 
Published: April 2018

The objective of the present study was to analyze the cellular and subcellular localization of ionotropic glutamate receptor subunits in midbrain dopaminergic neurons in the squirrel monkey. This was achieved by means of immunohistochemistry at light and electron microscopic levels andin situhybridization histochemistry.Colocalization studies show that nearly all dopaminergic neurons in both the ventral and dorsal tiers of the substantia nigra compacta (SNc-v, SNc-d) and the ventral tegmental area (VTA) are immunoreactive for AMPA (GluR1, GluR2/3, and GluR4) and NMDAR1 receptor subunits, but not for NMDAR2A/B subunits. The immunoreactivity of the receptor subunits is associated mainly with perikarya and dendritic shafts. Apart from the intensity of immunolabeling for the GluR4 subunit, which is quite similar for the different groups of midbrain dopaminergic neurons, the overall intensity of immunostaining for the other subunits is higher in the SNc-v and SNc-d than in the VTA. In line with these observations,in situhybridization shows that the average level of labeling for the GluR2 and NMDAR1 subunit mRNAs is significantly higher in the SNc-v than in the VTA, and for the NMDAR1 subunit, higher in the SNc-v than in the SNc-d. In contrast, no significant difference was found for the level of GluR1 mRNA labeling among the three groups of midbrain dopaminergic neurons. At the subcellular level in the SNc-v, AMPA (GluR1 and GluR2/3) and NMDAR1 receptor subunit immunoreactivity is preferentially associated with the postsynaptic densities of asymmetric synapses, but occasionally some immunoreactivity is found along nonsynaptic portions of plasma membranes of dendrites. A small number of preterminal axons, axon terminals, and glial cell processes are also immunoreactive.Our observations indicate that the different groups of midbrain dopaminergic neurons in primates exhibit a certain degree of heterogeneity with regard to the level of expression of some ionotropic glutamate receptor subunits. The widespread neuronal and glial localization of glutamate receptor subunits suggests that excitatory amino acids may act at different levels to control the basal activity and, possibly, to participate in the degeneration of midbrain dopaminergic neurons in Parkinson’s disease.
Control of Neurotransmitter Release by Presynaptic Waveform at the Granule Cell to Purkinje Cell Synapse
Authors: Sabatini Bernardo L. , Regehr Wade G. 
Published: April 2018

The effect of changes in the shape of the presynaptic action potential on neurotransmission was examined at synapses between granule and Purkinje cells in slices from the rat cerebellum. Low concentrations of tetraethylammonium were used to broaden the presynaptic action potential. The presynaptic waveform was monitored with voltage-sensitive dyes, the time course and amplitude of presynaptic calcium entry were determined with fluorescent calcium indicators, and EPSCs were measured with a whole-cell voltage clamp. Spike broadening increased calcium influx primarily by prolonging calcium entry without greatly affecting peak presynaptic calcium currents, indicating that the majority of calcium channels reach maximal probability of opening in response to a single action potential and that spike broadening increases the open time of these channels. EPSCs were exquisitely sensitive to elevations of calcium influx produced by spike broadening; there was a high power relationship between calcium influx and release such that a 23% increase in spike width led to a 25% increase in total calcium influx, which in turn doubled synaptic strength.The finding that even small changes in spike width influence neurotransmitter release suggests that altering the presynaptic waveform may be an important means of modifying the strength of this synapse. Waveform changes do not, however, contribute significantly to presynaptic modulation via activation of adenosine A1or GABABreceptors. Furthermore, greatly reducing presynaptic calcium influx did not alter the presynaptic waveform, indicating that calcium channels and calcium-activated channels do not participate in shaping the presynaptic waveform.
ε Subunit-Containing Acetylcholine Receptors in Myotubes Belong to the Slowly Degrading Population
Authors: Sala Carlo , O’Malley James , Xu Rufeng , Fumagalli Guido , Salpeter Miriam M. 
Published: April 2018

Two types of muscle acetylcholine receptors (AChRs) can be distinguished on the basis of their degradation rates and sensitivities to innervation, muscle activity, and agents elevating intracellular cAMP. The first type (Rs), is present in a stable form (degradationt½= ∼10 d) at the adult innervated neuromuscular junctions (NMJs). Rs can also exist in a less stable form (called accelerated Rs;t½= ∼3–5 d) at denervated NMJs and in aneurally cultured myotubes; agents that increase intracellular cAMP reversibly modulate Rs stability. The second type of AChR is a rapidly degrading receptor (Rr) expressed only in embryonic and noninnervated muscles. Rr can be stabilized by ATP and not by cAMP. This study tested the hypothesis that the degradation properties unique to the Rs are attributable to the presence of the ε subunit.Immunoprecipitation and Western blot analysis of AChRs extracted from rat muscle cells in tissue culture showed that AChRs recognized by antibodies against the ε subunit degraded as a single population with a half-life similar to that of the slow component, Rs, in these cells. In addition, as for Rs receptors in denervated NMJs and cultured muscle cell, the degradation rate of these ε-containing AChRs was stabilized by dibutyryl-cAMP. The data indicate that the ε-containing AChRs behave like Rs. Thus, the presence of the ε subunit is sufficient for selecting an AChR molecule to the Rs pool.
Neurons Produce a Neuronal Cell Surface-Associated Chondroitin Sulfate Proteoglycan
Authors: Lander Cynthia , Zhang Hong , Hockfield Susan 
Published: April 2018

Monoclonal antibody Cat-315 recognizes a chondroitin sulfate proteoglycan (CSPG) expressed on the surface of subsets of neurons in many areas of the mammalian CNS (Lander et al., 1997). The cell type-specific expression exhibited by the Cat-315 CSPG and other perineuronal net CSPGs imparts a distinct molecular surface identity to a neuron (Celio and Blumcke, 1994; Lander et al., 1997). The cell type(s) producing these surface-associated proteins and yielding this cellular diversity has remained in question. The expression of the Cat-315 CSPG in primary rat cortical cultures has permitted an examination of the cellular source of the Cat-315 antigen, as well as a determination of its spatial relationship to the neuronal surface.Live-cell labeling of primary neuronal cultures demonstrates that the Cat-315 CSPG is on the extracellular surface of neurons. Furthermore, extraction experiments demonstrate that the Cat-315 CSPG lacks a transmembrane domain and that the entire molecule is extracellular and, therefore, can be considered a constituent of brain extracellular matrix. Several lines of evidence indicate that neurons with cell surface staining produce the Cat-315 CSPG. First, neurons with cell surface staining also show intracellular Cat-315 immunoreactivity. Second, β-xyloside or monensin, reagents that inhibit the synthesis and transport of CSPGs, increase intracellular Cat-315 immunoreactivity within neurons that express cell surface Cat-315 immunoreactivity. Third, double labeling with Cat-315 and a polyclonal antibody for the Golgi complex demonstrates a precise colocalization of the intracellular Cat-315 immunoreactivity with the Golgi. Together, these observations demonstrate that neurons contribute to the extracellular matrix of brain and that the Cat-315 CSPG is produced by the neurons that carry Cat-315 cell surface immunoreactivity.
Internalization of D1 Dopamine Receptor in Striatal NeuronsIn Vivoas Evidence of Activation by Dopamine Agonists
Authors: Dumartin Brigitte , Caillé Isabelle , Gonon Francois , Bloch Bertrand 
Published: April 2018

To investigate how dopamine influences the subcellular localization of the dopamine receptors in the striatal dopaminoceptive neurons, we have used immunohistochemistry to detect D1 dopamine receptors (D1R) after modifications of the dopamine environment. In normal rats, D1R are located mostly extrasynaptically at the plasma membrane of the cell bodies, dendrites, and spines. The intrastriatal injection of the full D1R agonist SKF-82958 and the intraperitoneal injection of the same molecule or of amphetamine (which induces a massive release of dopamine in the striatum) induce modifications of the pattern of D1R immunoreactivity in the dorsal and ventral striatum. Whereas normal rats display homogenous staining of the neuropile with staining of the plasma membrane of the cell bodies, either treatment provokes the appearance of an intense immunoreactivity in the cytoplasm and the proximal dendrites. The labeling pattern is heterogeneous and more intense in the striosomes than in the matrix. Analysis of semithin sections and electron microscopy studies demonstrates a translocation of the labeling from the plasma membrane to endocytic vesicles and endosomes bearing D1R immunoreactivity in the cytoplasm of cell bodies and dendrites. Injection of D1R antagonist (SCH-23390) alone or injection of D1R antagonist, together with amphetamine or SKF-82958, do not provoke modification of the immunoreactivity, as compared with normal rat.Our results demonstrate that,in vivo, the acute activation of dopamine receptors by direct agonists or endogenously released dopamine provokes dramatic modifications of their subcellular distribution in neurons, including internalization in the endosomal compartment in the cytoplasm. This suggests that modifications of the localization of neurotransmitter receptors, including extrasynaptic ones, may be a critical event that contributes to the postsynaptic responsein vivo.
Parallel Projection of Amplitude and Phase Information from the Hindbrain to the Midbrain of the African Electric FishGymnarchus niloticus
Authors: Kawasaki Masashi , Guo Yuan-Xing 
Published: April 2018

Two distinct sensory cues in electrosensory signals, amplitude modulation and differential phase modulation, are essential for an African wave-type electric fish,Gymnarchus, to perform the jamming avoidance responses. Individual neurons in the first brain station for central processing, the electrosensory lateral line lobe (ELL), were investigated by thein vivowhole-cell recording and labeling technique for their physiological responses, location, morphology, and projection areas.Neurons in the dorsal zone of the ELL responded selectively to amplitude modulation. Neurons in the outer cell layer of the medial zone were categorized physiologically into two groups: amplitude-sensitive and differential phase-sensitive. All but one neuron in the inner cell layer of the medial zone responded exclusively to differential phase modulation. All neurons recorded and labeled in the ELL had pyramidal morphology with large and extensive apical dendrites and less extensive basal dendrites. They were found to project to two midbrain nuclei: the nucleus praeeminentialis and the torus semicircularis. Amplitude-sensitive neurons in the dorsal zone projected exclusively to the lateral posterior subdivision, the torus semicircularis. Neurons in the medial zone projected to the medial dorsal and lateral anterior subdivisions of the torus semicircularis.Although some neurons in the ELL responded to both amplitude and differential phase modulation, they did not differentiate between temporal patterns of the two cues that encode necessary information for the jamming avoidance response. Overlapping projection of amplitude and differential phase-sensitive neurons to the torus semicircularis suggests integration of the two sensory cues in this nucleus.
Subcellular Redistribution of m2 Muscarinic Acetylcholine Receptors in Striatal InterneuronsIn Vivoafter Acute Cholinergic Stimulation
Authors: Bernard Véronique , Laribi Ouahiba , Levey Allan I. , Bloch Bertrand 
Published: April 2018

The purpose of our work was to investigate how the cholinergic environment influences the targeting and the intracellular trafficking of the muscarinic receptor m2 (m2R)in vivo. To address this question, we have used immunohistochemical approaches at light and electron microscopic levels to detect the m2R in control rats and rats treated with muscarinic receptor agonists.In control animals, m2Rs were located mostly at postsynaptic sites at the plasma membrane of perikarya and dendrites of cholinergic and NPY–somatostatin interneurons as autoreceptors and heteroreceptors, respectively. Presynaptic receptors were also detected in boutons. The m2Rs were usually detected at extrasynaptic sites, but they could be found rarely in association with symmetrical synapses, suggesting that the cholinergic transmission mediated by m2R occurs via synaptic and nonsynaptic mechanisms. The stimulation of muscarinic receptors with oxotremorine provoked a dramatic alteration of m2R compartmentalization, including endocytosis with a decrease of the density of m2R at the membrane (−63%) and an increase of those associated with endosomes (+86%) in perikarya. The very strong increase of m2R associated with multivesicular bodies (+732%) suggests that oxotremorine activated degradation. The slight increase in the Golgi apparatus (+26%) suggests that the m2R stimulation had an effect on the maturation of m2R. The substance P receptor located at the membrane of the same neurons was unaffected by oxotremorine.Our data demonstrate that cholinergic stimulation dramatically influences the subcellular distribution of m2R in striatal interneuronsin vivo. These events may have key roles in controlling abundance and availability of muscarinic receptors via regulation of receptor endocytosis, degradation, and/or neosynthesis. Further, the control of muscarinic receptor trafficking may influence the activity of striatal interneurons, including neurotransmitter release and/or electric activity.
Early Visual Experience Shapes the Representation of Auditory Space in the Forebrain Gaze Fields of the Barn Owl
Authors: Miller Greg L. , Knudsen Eric I. 
Published: April 2018

Auditory spatial information is processed in parallel forebrain and midbrain pathways. Sensory experience early in life has been shown to exert a powerful influence on the representation of auditory space in the midbrain space-processing pathway. The goal of this study was to determine whether early experience also shapes the representation of auditory space in the forebrain.Owls were raised wearing prismatic spectacles that shifted the visual field in the horizontal plane. This manipulation altered the relationship between interaural time differences (ITDs), the principal cue used for azimuthal localization, and locations of auditory stimuli in the visual field. Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls.Prism rearing altered the representation of ITD in the AAr. In prism-reared owls, unit tuning for ITD was shifted in the adaptive direction, according to the direction of the optical displacement imposed by the spectacles. Changes in ITD tuning involved the acquisition of unit responses to adaptive ITD values and, to a lesser extent, the elimination of responses to nonadaptive (previously normal) ITD values. Shifts in ITD tuning in the AAr were similar to shifts in ITD tuning observed in the optic tectum of the same owls.This experience-based adjustment of binaural tuning in the AAr helps to maintain mutual registry between the forebrain and midbrain representations of auditory space and may help to ensure consistent behavioral responses to auditory stimuli.
A mikro-RNS-ek patogenetikai szerepe és expressziós mintázata praeeclampsiában
Authors: Biró Orsolya , Rigó Jr. János 
Published: April 2018

Abstract: Preeclampsia is the leading cause of maternal and fetal morbidity and mortality that affects 3–8% of pregnancies worldwide. Its main symptoms include new onset of high blood pressure and proteinuria after 20 weeks of pregnancy. The cause of the disease is still debated. microRNAs are short, non-coding RNA molecules that play a pivotal part in the posttranscriptional regulation of eukaryotic genes. They are involved in fine-tuning of vital physiological processes such as cell cycle, proliferation, differentiation and cell death. In genomic studies, hundreds of microRNAs were detected in the placenta, which are supposed to regulate placental development and contribute to uncomplicated pregnancy. Several studies have reported changes in the expression of microRNAs in pregnancy. Abnormal microRNA expression may have a role in the development of preeclampsia as it affects the proliferation, migration, and invasion of the trophoblast cells, spiral artery remodeling, and angiogenesis. Some placental microRNAs (e.g., the C19MC microRNA cluster) are able to reach the maternal circulation through their release via exosomes from the trophoblast layer. These ‘circulating’ microRNA molecules can be applied as biomarkers for the detection of various placental disorders owing to their stability and specificity. Orv Hetil. 2018; 159(14): 547–556.
Participants’ experiences of a mixed-ability yoga series
Authors: Bevis Alexandra , Waterworth Kate , Mudge Suzie 
Published: April 2018

The practice of yoga encourages individuals to work within their own bodies to bring balance and health to the mind, body and spirit, providing relief for symptoms of chronic conditions. The purpose of this study was to explore the experiences of individuals participating in a series of mixed-ability yoga classes. Barriers and facilitators to their participation were also explored. Seven participants were recruited from the mixed physical and mental ability yoga classes. Semi–structured interviews were used to collect data. Thematic analysis was used to analyse the data and develop themes. Prominent themes were Engagement Partnerships, Physical Activity Beliefs, Supported Participation and Concepts of Disability. These themes provided insight into the experiences of participants and the facilitators and barriers that influenced their participation. Additionally, themes were supported by literature on group cohesion and self-efficacy that highlight the potential for change to group exercise classes with cross over into rehabilitation classes. The importance of appropriate adaptation through skilled instructors was key to the success of the mixed-ability yoga series, as was the promotion of inclusion and understanding of perceptions of disability. Participants experienced health benefits from the mixed-ability yoga class. The fundamental concepts of the class can be applied in physiotherapy practice to promote physical activity for all.
IMPROVEMENT OF MATHEMATICAL MODELS FOR ESTIMATION OF TRAIN DYNAMICS
Authors: Ursulyak L. V. , Shvets A. O. 
Published: April 2018

Purpose. Using scientific publications the paper analyzes the mathematical models developed in Ukraine, CIS countries and abroad for theoretical studies of train dynamics and also shows the urgency of their further improvement. Methodology. Information base of the research was official full-text and abstract databases, scientific works of domestic and foreign scientists, professional periodicals, materials of scientific and practical conferences, methodological materials of ministries and departments. Analysis of publications on existing mathematical models used to solve a wide range of problems associated with the train dynamics study shows the expediency of their application. Findings. The results of these studies were used in: 1) design of new types of draft gears and air distributors; 2) development of methods for controlling the movement of conventional and connected trains; 3) creation of appropriate process flow diagrams; 4) development of energy-saving methods of train driving; 5) revision of the Construction Codes and Regulations (SNiP ΙΙ-39.76); 6) when selecting the parameters of the autonomous automatic control system, created in DNURT, for an auxiliary locomotive that is part of a connected train; 7) when creating computer simulators for the training of locomotive drivers; 8) assessment of the vehicle dynamic indices characterizing traffic safety. Scientists around the world conduct numerical experiments related to estimation of train dynamics using mathematical models that need to be constantly improved. Originality. The authors presented the main theoretical postulates that allowed them to develop the existing mathematical models for solving problems related to the train dynamics. The analysis of scientific articles published in Ukraine, CIS countries and abroad allows us to determine the most relevant areas of application of mathematical models. Practicalvalue. The practical value of the results obtained lies in the scientific validity and applied orientation of theoretical studies using mathematical models, the improvement of which will expand the range of problems to be solved, and increase the level of reliability of the results obtained.
Changes in Serum Iron, Total Iron Binding Capacity and Transferrin Saturation Percent in Sudanese Females Newly Diagnosed with Breast Cancer at Khartoum Oncology Hospital: A case- control study
Authors: Mustafa Rufaida Mustafa Ahmed , Husain Nazik Elmalaika Obaid Seid Ahmed 
Published: April 2018

Background:Iron is a vital constituent of cells but in excess may be harmful and is associated with a raised risk for some malignant diseases including breast cancer. We aimed to study changes in iron profile in Sudanese females newly diagnosed with breast cancer.Methods: A case- control study in which serum iron, Total Iron Binding Capacity (TIBC), and transferrin saturation percent were measured for fifty females with breast cancer referred to Khartoum Oncology Hospital and seventy apparently healthy females, using manual method (IRON-FERROZINE). Results: Mean age was 47years and 42years in cases and control, respectively and the mean of parity was 4 in both groups. Mean of serum iron ±SD in case group was 244.30 ± 151.598(µg/dL)and in control group was 57.59 ± 43.191(µg/dL) (P. value = 0.000). Mean of TIBC ±SD in cases was 412.98 ± 177.460(µg/dL)and in controls it was 403.71 ± 168.765(µg/dL) (P.value = 0.838). The mean of transferrin saturation percent ± SD in cases was 61.08 % ±41.523 and in controls was 223.23 % ±149.195 (P.value=0.000). The mean of TIBC in grade I 343.00(µg/dL), 467.10(µg/dL) in grade II and 321.25(µg/dL) in grade III (P.value 0.019).Conclusion: There is a statistically significant increase in the mean of serum iron and decrease in transferrin saturation percent in women with breast cancer. TIBC vary significantly according to histopathological grade. Serum iron and transferrin saturation percent may be helpful as biochemical risk markers for breast cancer and TIBC may act as a predictor of disease grade.