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The study of the pathogenesis of febrile seizures and their consequences frequently necessitates gene expression analysis. The primary methodology employed for such analysis is reverse transcription with quantitative polymerase chain reaction (RT-qPCR). To ensure the accuracy of data obtained by RT-qPCR, it is crucial to utilize stably expressed reference genes. The objective of this study was to identify the most suitable reference genes for use in the analysis of mRNA production in various brain regions of rats following prolonged neonatal febrile seizures. The expression stability of eight housekeeping genes was evaluated using the online tool RefFinder in the dorsal and ventral hippocampal regions and in the temporal and medial prefrontal cortex of the brain. The Ppia gene exhibited the greatest stability of expression. Conversely, the genes with the least stable expression levels were Actb and Ywhaz; thus, it is not recommended to use them for normalization in a febrile seizure model. Additionally, the majority of housekeeping genes demonstrate age-related, region-specific fluctuations. Therefore, it is crucial to employ the appropriate housekeeping genes for each brain structure under investigation when examining the expression dynamics of genes of interest in a febrile seizure model. [ABSTRACT FROM AUTHOR]

The role of astroglial and microglial cells in the pathogenesis of epilepsy is currently under active investigation. It has been proposed that the activity of these cells may be regulated by the agonists of peroxisome proliferator-activated nuclear receptors (PPARs). This study investigated the effects of a seven-day treatment with the PPAR β/δ agonist GW0742 (Fitorine, 5 mg/kg/day) on the behavior and gene expression of the astroglial and microglial proteins involved in the regulation of epileptogenesis in the rat brain within a lithium–pilocarpine model of temporal lobe epilepsy (TLE). TLE resulted in decreased social and increased locomotor activity in the rats, increased expression of astro- and microglial activation marker genes (Gfap, Aif1), pro- and anti-inflammatory cytokine genes (Tnfa, Il1b, Il1rn), and altered expression of other microglial (Nlrp3, Arg1) and astroglial (Lcn2, S100a10) genes in the dorsal hippocampus and cerebral cortex. GW0742 attenuated, but did not completely block, some of these impairments. Specifically, the treatment affected Gfap gene expression in the dorsal hippocampus and Aif1 gene expression in the cortex. The GW0742 injections attenuated the TLE-specific enhancement of Nlrp3 and Il1rn gene expression in the cortex. These results suggest that GW0742 may affect the expression of some genes involved in the regulation of epileptogenesis. [ABSTRACT FROM AUTHOR]

The closed-loop control of pathological brain activity is a challenging task. In this study, we investigated the sensitivity of continuous epileptiform short discharge generation to electrical stimulation applied at different phases between the discharges using an in vitro 4-AP-based model of epilepsy in rat hippocampal slices. As a measure of stimulation effectiveness, we introduced a sensitivity function, which we then measured in experiments and analyzed with different biophysical and abstract mathematical models, namely, (i) the two-order subsystem of our previous Epileptor-2 model, describing short discharge generation governed by synaptic resource dynamics; (ii) a similar model governed by shunting conductance dynamics (Epileptor-2B); (iii) the stochastic leaky integrate-and-fire (LIF)-like model applied for the network; (iv) the LIF model with potassium M-channels (LIF+KM), belonging to Class II of excitability; and (v) the Epileptor-2B model with after-spike depolarization. A semi-analytic method was proposed for calculating the interspike interval (ISI) distribution and the sensitivity function in LIF and LIF+KM models, which provided parametric analysis. Sensitivity was found to increase with phase for all models except the last one. The Epileptor-2B model is favored over other models for subthreshold oscillations in the presence of large noise, based on the comparison of ISI statistics and sensitivity functions with experimental data. This study also emphasizes the stochastic nature of epileptiform discharge generation and the greater effectiveness of closed-loop stimulation in later phases of ISIs. [ABSTRACT FROM AUTHOR]

Epilepsy is known to cause alterations in neural networks. However, many details of these changes remain poorly understood. The objective of this study was to investigate changes in the properties of hippocampal CA1 pyramidal neurons and their synaptic inputs in a rat lithium–pilocarpine model of epilepsy. In the chronic phase of the model, we found a marked loss of pyramidal neurons in the CA1 area. However, the membrane properties of the neurons remained essentially unaltered. The results of the electrophysiological and morphological studies indicate that the direct pathway from the entorhinal cortex to CA1 neurons is reinforced in epileptic animals, whereas the inputs to them from CA3 are either unaltered or even diminished. In particular, the dendritic spine density in the str. lacunosum moleculare, where the direct pathway from the entorhinal cortex terminates, was found to be 2.5 times higher in epileptic rats than in control rats. Furthermore, the summation of responses upon stimulation of the temporoammonic pathway was enhanced by approximately twofold in epileptic rats. This enhancement is believed to be a significant contributing factor to the heightened epileptic activity observed in the entorhinal cortex of epileptic rats using an ex vivo 4-aminopyridine model. [ABSTRACT FROM AUTHOR]

Reverse transcription followed by quantitative polymerase chain reaction (RT-qPCR) is a commonly used tool for gene expression analysis. The selection of stably expressed reference genes is required for accurate normalization. The aim of this study was to identify the optimal reference genes for RT-qPCR normalization in various brain regions of rats at different stages of the lithium–pilocarpine model of acquired epilepsy. We tested the expression stability of nine housekeeping genes commonly used as reference genes in brain research: Actb, Gapdh, B2m, Rpl13a, Sdha, Ppia, Hprt1, Pgk1, and Ywhaz. Based on four standard algorithms (geNorm, NormFinder, BestKeeper, and comparative delta-Ct), we found that after pilocarpine-induced status epilepticus, the stability of the tested reference genes varied significantly between brain regions and depended on time after epileptogenesis induction (3 and 7 days in the latent phase, and 2 months in the chronic phase of the model). Pgk1 and Ywhaz were the most stable, while Actb, Sdha, and B2m demonstrated the lowest stability in the analyzed brain areas. We revealed time- and region-specific changes in the mRNA expression of the housekeeping genes B2m, Actb, Sdha, Rpl13a, Gapdh, Hprt1, and Sdha. These changes were more pronounced in the hippocampal region during the latent phase of the model and are thought to be related to epileptogenesis. Thus, RT-qPCR analysis of mRNA expression in acquired epilepsy models requires careful selection of reference genes depending on the brain region and time of analysis. For the time course study of epileptogenesis in the rat lithium–pilocarpine model, we recommend the use of the Pgk1 and Ywhaz genes. [ABSTRACT FROM AUTHOR]

This paper studies the composition and properties of shells of bivalve mollusks (Crenomytilus grayanus, Callista brevisiphonata, and Mizuhopecten yessoensis) from coastal discharges with a view to the possibility of their use in photocatalytic water treatment systems. The clam shells are considered in terms of application in the form of a powder material as a precursor for creating photocatalysts, and also as a carrier of photocatalytic coatings. It was shown that the main phase composing the shell material was calcium carbonate in two crystallographic modifications—calcite and aragonite. The presence of inorganic impurities in all studied clam shells did not exceed one mass percent. The main share was made up of elements included in the composition of calcium carbonate, which confirmed the high bio-indifference of the materials under study. Depending on the physiological and environmental features of the structure of clam shells, different contents of the organic component in their composition were observed. The granulometric characteristics of crushed clam shells (average diameter, specific surface area, and distribution modality) were studied. It was shown that the maximum values of bending strength of 5 MPa and compressive strength of 2 MPa are characterized by Mizuhopecten yessoensis shells with the lowest porosity of 2.91%. The features of sorption and photosorption processes of both whole and crushed shells in relation to four organic dyes at different temperatures and degrees of illumination were studied. Based on crushed shells of Mizuhopecten Yessoensis and titanium dioxide, functional materials (CaxTiyOz) were obtained, and their morphology and photocatalytic properties were studied. An example of the practical use of clam shells as a carrier of a photocatalytic coating is given. [ABSTRACT FROM AUTHOR]

Low-frequency electrical stimulation is used to treat some drug-resistant forms of epilepsy. Despite the effectiveness of the method in suppressing seizures, there is a considerable risk of side effects. An optogenetic approach allows the targeting of specific populations of neurons, which can increase the effectiveness and safety of low-frequency stimulation. In our study, we tested the efficacy of the suppression of ictal activity in entorhinal cortex slices in a 4-aminopyridine model with three variants of low-frequency light stimulation (LFLS): (1) activation of excitatory and inhibitory neurons (on Thy1-ChR2-YFP mice), (2) activation of inhibitory interneurons only (on PV-Cre mice after virus injection with channelrhodopsin2 gene), and (3) hyperpolarization of excitatory neurons (on Wistar rats after virus injection with archaerhodopsin gene). Only in the first variant did simultaneous LFLS of excitatory and inhibitory neurons replace ictal activity with interictal activity. We suggest that LFLS caused changes in the concentration gradients of K+ and Na+ cations across the neuron membrane, which activated Na-K pumping. According to the mathematical modeling, the increase in Na-K pump activity in neurons induced by LFLS led to an antiepileptic effect. Thus, a less specific and generalized optogenetic effect on entorhinal cortex neurons was more effective in suppressing ictal activity in the 4-aminopyridine model. [ABSTRACT FROM AUTHOR]

Molecular-beam epitaxial growth of Si-doped GaAs single-crystal layers on (110)-oriented GaAs substrates has been studied. The surface morphology of grown films was analyzed by scanning electron microscopy and atomic force microscopy, and the crystal structure of grown films was estimated by X-ray grazing incidence diffraction, in-plane pole figures, reciprocal space mapping, and photoluminescence spectroscopy. The type, concentration, and mobility of charge carriers in films were measured by the four-probe method in van der Pauw geometry at temperatures of 300 and 77 K. The possible existence of two areas in growth conditions, where increased concentration and mobility of electrons are achieved, was shown: the first, main area with the highest concentration and mobility values is Tg = 450–500 °C and V/III ratio γ = 20–40, the second, minor one is Tg = 600–680 °C and γ = 40–70. The hole conductivity was obtained at a growth temperature of 580 °C and a low γ value of 16. It was also shown that the defect-free crystal structure of the films grown at high temperatures is not necessarily accompanied by a smooth surface. [ABSTRACT FROM AUTHOR]

Maternal hyperhomocysteinemia (HCY) is a common pregnancy complication caused by high levels of the homocysteine in maternal and fetal blood, which leads to the alterations of the cognitive functions, including learning and memory. In the present study, we investigated the mechanisms of these alterations in a rat model of maternal HCY. The behavioral tests confirmed the memory impairments in young and adult rats following the prenatal HCY exposure. Field potential recordings in hippocampal slices demonstrated that the long-term potentiation (LTP) was significantly reduced in HCY rats. The whole-cell patch-clamp recordings in hippocampal slices demonstrated that the magnitude of NMDA receptor-mediated currents did not change while their desensitization decreased in HCY rats. No significant alterations of glutamate receptor subunit expression except GluN1 were detected in the hippocampus of HCY rats using the quantitative real-time PCR and Western blot methods. The immunofluorescence microscopy revealed that the number of synaptopodin-positive spines is reduced, while the analysis of the ultrastructure of hippocampus using the electron microscopy revealed the indications of delayed hippocampal maturation in young HCY rats. Thus, the obtained results suggest that maternal HCY disturbs the maturation of hippocampus during the first month of life, which disrupts LTP formation and causes memory impairments. [ABSTRACT FROM AUTHOR]