Search results for "Transmission"

ORGANIZATION OF HIGHER-LEVEL CHROMATIN STRUCTURES (CHROMOMERE, CHROMONEMA AND CHROMATIN BLOCK) EXAMINED USING VISIBLE LIGHT-INDUCED CHROMATIN PHOTO-S…

2002

The method of chromatin photo-stabilization by the action of visible light in the presence of ethidium bromide was used for investigation of higher-level chromatin structures in isolated nuclei. As a model we used rat hepatocyte nuclei isolated in buffers which stabilized or destabilized nuclear matrix. Several higher-level chromatin structures were visualized: 100 nm globules—chromomeres, chains of chromomeres—chromonemata, aggregates of chromomeres—blocks of condensed chromatin. All these structures were completely destroyed by 2 M NaCl extraction independent of the matrix state, and DNA was extruded from the residual nuclei (nuclear matrices) into a halo. These results show that nuclear …

Cellular Mechanisms of Subplate-Driven and Cholinergic Input-Dependent Network Activity in the Neonatal Rat Somatosensory Cortex

2008

Early coordinated network activity promotes the development of cortical structures. Although these early activity patterns have been recently characterized with respect to their developmental, spatial and dynamic properties, the cellular mechanisms by which specific neuronal populations trigger coordinated activity in the neonatal cerebral cortex are still poorly understood. Here we characterize the cellular and molecular processes leading to generation of network activity during early postnatal development. We show that the somatosensory cortex of newborn rats expresses cholinergic-driven calcium transients which are synchronized within the deeply located subplate. Correspondingly, endogen…

Haploinsufficiency of Tsc2 Leads to Hyperexcitability of Medial Prefrontal Cortex via Weakening of Tonic GABAB Receptor-mediated Inhibition.

2020

Abstract Loss-of-function mutation in one of the tumor suppressor genes TSC1 or TSC2 is associated with several neurological and psychiatric diseases, including autism spectrum disorders (ASDs). As an imbalance between excitatory and inhibitory neurotransmission, E/I ratio is believed to contribute to the development of these disorders, we investigated synaptic transmission during the first postnatal month using the Tsc2+/− mouse model. Electrophysiological recordings were performed in acute brain slices of medial prefrontal cortex. E/I ratio at postnatal day (P) 15–19 is increased in Tsc2+/− mice as compared with wildtype (WT). At P25–30, facilitated GABAergic transmission reduces E/I rati…

Active spike transmission in the neuron model with a winding threshold manifold

2012

International audience; We analyze spiking responses of excitable neuron model with a winding threshold manifold on a pulse stimulation. The model is stimulated with external pulse stimuli and can generate nonlinear integrate-and-fire and resonant responses typical for excitable neuronal cells (all-or-none). In addition we show that for certain parameter range there is a possibility to trigger a spiking sequence with a finite number of spikes (a spiking message) in the response on a short stimulus pulse. So active transformation of N incoming pulses to M (with M>N) outgoing spikes is possible. At the level of single neuron computations such property can provide an active "spike source" comp…

Synthesis of Hierarchically Grown ZnO@NT-WS2 Nanocomposites

2009

A chemically specific and facile method for growth of ZnO nanorods on WS2 nanotubes (NT-WS2) is reported. The modification strategy is based on the chalcophilic affinity of Zn, which serves as an anchor to immobilize ZnO colloids onto the WS2 nanotubes. The surface bound ZnO colloids have been used as a seed to grow ZnO nanorods on WS2 nanotubes. The immobilization of ZnO colloids was monitored by UV−vis spectroscopy and photoluminescence spectroscopy whereas the growth of ZnO nanorods was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

The fine structural organization of sternal glands of pseudergates and workers in termites (Isoptera): a comparative survey

2008

1873-5495 (Electronic) Comparative Study Journal Article; Thirty-nine species belonging to different families of termites are studied to give a comprehensive view of the evolution of the sternal glands. Several modifications occurring at cuticular and cytological levels are described in neuter castes. The outer epicuticle is always pierced by epicuticular pores. In advanced termites the epicuticular filaments greatly increase in number and length creating a thick layer. The pore canals gradually enlarge while the cuticle changes into a lattice structure lining an extracellular space in which the secretion is stored. Two classes of cells are present in basal termites (Mastotermitidae, Hodote…

Conflict between parasites with different transmission strategies infecting an amphipod host

2005

Competition between parasites within a host can influence the evolution of parasite virulence and host resistance, but few studies examine the effects of unrelated parasites with conflicting transmission strategies infecting the same host. Vertically transmitted (VT) parasites, transmitted from mother to offspring, are in conflict with virulent, horizontally transmitted (HT) parasites, because healthy hosts are necessary to maximize VT parasite fitness. Resolution of the conflict between these parasites should lead to the evolution of one of two strategies: avoidance, or sabotage of HT parasite virulence by the VT parasite. We investigated two co-infecting parasites in the amphipod host, G…

S1/4 Domain compliance and elastic power transmission in FOF1F0F1-ATPase

2008

Preparation and characterisation of Ce:YAG -polycarbonate composites for white LED

2016

Ce:YAG-polycarbonate composites were prepared with several amounts of Ce:YAG in the range 0.1-5 wt.% by using melt compounding. The structure and morphology of the composites were investigated by means of X-ray diffractometry and transmission electron microscopy. The optical properties of the composites were studied by using photoluminescence spectroscopy. The intermolecular interaction between the polymer and the filler surface was investigated using 13C cross-polarization magic-angle spinning NMR spectroscopy (13C {1H} CP-MAS NMR). The results showed that the dispersion of the particles in the polymer, and the optical properties, depend on the Ce:YAG amount. The composites were combined w…

Table Compression

2016

Data Compression Techniques for massive tables are described. Related methodological results are also presented.