Opera Medica et Physiologica

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Printed May 31, 2019;
Published ahead of print May 20, 2019; Printed May 31, 2019; OM&P 2019 Volume 5 Supplement S 1, pages 7-11
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Function and plasticity of synapses.pdf475.73 KB

Printed May 31, 2019;
Published ahead of print May 20, 2019; Printed May 31, 2019; OM&P 2019 Volume 5 Supplement S 1, pages 12-16
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Printed May 31, 2019;
Published ahead of print May 20, 2019; Printed May 31, 2019; OM&P 2019 Volume 5 Supplement S 1, pages 17-23
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Neuron-glia interactions.pdf500.76 KB

Printed May 31, 2019;
Published ahead of print May 20, 2019; Printed May 31, 2019; OM&P 2019 Volume 5 Supplement S 1
Abstract Full Text
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author index.pdf284.76 KB

Printed May 31, 2019;
Published ahead of print May 20, 2019; Printed May 31, 2019; OM&P 2019 Volume 5 Supplement S 1, pages 1-6
Abstract Full Text

Printed March 30, 2019;
Published ahead of print March 29, 2019; Printed March 30, 2019; OM&P 2019 Volume 5 Issue 1, pages 7-16; doi:10.20388/omp2019.001.0063
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Computational models for two neuron/astrocyte networks are developed to explore mechanisms underlying the astrocytes’ role in maintaining neuronal firing patterns. For the first network, a single neuron receives periodic excitatory inputs at varying frequencies. We consider the role played by several astrocytic dendritic processes, including the Na+-K+ ATPase pump, K+  channels and gap junctions in maintaining extracellular ion homeostasis so that the neuron can faithfully sustain spiking in response to the excitatory input. The second network includes two neurons coupled through mutual inhibitory synapses. Here we consider the role of astrocytic dendritic processes in maintaining anti-phase or synchronous oscillations. Dynamical systems methods, including bifurcation theory and fast/slow analysis, is used to systematically reduce the complex model to a simpler set of equations. In particular, the first network, consisting of differential equations for the neuron and astrocyte membrane potentials, channel state variables and intracellular and extracellular Na+ and K+ concentrations, is reduced to a one dimensional map. Fixed points of the map determine whether the astrocyte can maintain extracellular K+ homeostasis so the neuron can respond to periodic input. 

 

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omp2019.001.0063.pdf3.65 MB

Printed March 30, 2019;
Published ahead of print March 29, 2019; Printed March 30, 2019; OM&P 2019 Volume 5 Issue 1, pages 1-6; doi:10.20388/omp2019.001.0062
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Axo-axonal interactions of neuronal cells play an important role in functional development during embryogenesis. Axons of the cells formed on early stages of the brain development provide a template for the growing axons of later axons. However, the mechanisms of the guiding of younger axons by already formed axons are not well understood. In this study, we present a method to study such axo-axonal interactions in vitro using microfluidics methods and culturing neocortical cells. We studied the dynamics of axon growth in microchannels perpendicularly intersecting with other microchannels. This study provides fundamental understanding of the axonal navigation in microfluidic structures, which further facilitate the design of  experimental in vitro model for studying the role of already formed axons in the development of neuronal system.

 

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omp2019.001.0062_corrected.pdf21.78 MB

Printed December 24, 2018;
Published ahead of print December 20, 2018; Printed December 24, 2018; OM&P 2018 Volume 4 Issue 3, 4, pages 86-96; doi:10.20388/omp2018.003.0060
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In this study we examined the intersection of two molecular pathways both known to regulate dentate development – the Emx2 transcription factor and the Sonic Hedgehog (Shh) morphogenic scignaling pathway. We confirmed that Emx2 mutant mice have a markedly reduced dentate gyrus and studied evidence of changes in Shh signaling and Shh expression in these mutants. Our results indicate that loss of Emx2 affects the numbers and distribution of Gli+ ventrally derived dentate neural stem cells that are responsible for populating the perinatal dentate gyrus. Accompanying this, we find that Emx2 mutants have reduced expression of Shh in the amygdalo-hippocampal region. In addition, there are ectopic Shh responsive progenitors that fail to properly populate the dentate. Taken together our results indicate that Emx2 regulates dentate development in part by altering availability and signaling of Shh.

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omp2018.003.0060.pdf2.86 MB

Printed December 24, 2018;
Published ahead of print December 10, 2018; Printed December 24, 2018; OM&P 2018 Volume 4 Issue 3, 4, pages 97-99
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For many decades synaptic circuits have been associated solely with cell-cell neuronal connections represented by the presynaptic terminal, which releases a neurotransmitter, and the postsynaptic neuronal specialization, a site where the neurotransmitter can activate synaptic receptors. However, due to technical limitations these studies usually were linked only to the postsynaptic site. For a long while, the widespread techniques that rapidly advanced neurophysiology have been little used in understanding the way how Ca2+-dependent release of the excitatory neurotransmitter glutamate from neuronal axons can be measured directly. Only with the advance of live cell imaging, it became possible to detect internal Ca2+ dynamics in presynaptic boutons with the high temporal resolution.

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popov proof v2.pdf411.64 KB

Printed December 24, 2018;
Published ahead of print December 10, 2018; Printed December 24, 2018; OM&P 2018 Volume 4 Issue 3, 4, pages 78-85; doi:10.20388/omp2018.003.0061
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omp2018.003.0061.pdf2.06 MB

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