There is ample experimental evidence supporting the hypothesis that the brain serotonergic system is involved in the control of chronic social defeat stress (CSDS), depression, and anxiety. The study ...aimed to analyze mRNA levels of the serotonergic genes in the raphe nuclei of midbrain that may be associated with chronic social defeats consistently shown by male mice in special experimental settings. The serotonergic genes were the
Tph2
,
Sert
,
Maoa
, and
Htr1a
. The
Bdnf
and
Creb
genes were also studied. The experimental groups were composed of male mice with experience of defeats in 21 daily encounters and male mice with the same track record of defeats followed by a no-defeat period without agonistic interactions (relative rest for 14 days). It has been shown that mRNA levels of the
Tph2
,
Maoa
,
Sert
,
Htr1a
,
Bdnf
, and
Creb
genes in the raphe nuclei of defeated mice are decreased as compared with the controls. The expression of the serotonergic genes as well as the
Creb
gene is not restored to the control level after the 2 weeks of relative rest. mRNA levels of
Bdnf
gene are not recovered to the control levels, although some upregulation was observed in rested losers. CSDS experience inducing the development of mixed anxiety/depression-like state in male mice downregulates the expression of serotonergic genes associated with the synthesis, inactivation, and reception of serotonin. The
Bdnf
and
Creb
genes in the midbrain raphe nuclei are also downregulated under CSDS. Period of relative rest is not enough for most serotonergic genes to recover expression to the control levels.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The concept of a major inhibitory role of serotonin in aggressive behavior is widely accepted by researchers. There were ample evidences that a pharmacologically-induced increase in serotonergic ...activity attenuates agonistic behavior, and the manipulations inhibiting the brain serotonergic system can elicit aggressiveness in animals. Ealier, experimental studies have demonstrated reduced metabolism in brain serotonergic system and specific changes in pharmacological sensitivity of 5-HT(1A) receptors in male mice with repeated experience of aggression. It has been shown that mRNA levels of the serotonergic genes in the midbrain raphe nuclei are reduced in aggressive males. After no-fight period expression of some genes is restored or becomes higher compared with the controls on the background of increased aggression. The review provides data supporting and contradicting the serotonin-deficiency hypothesis of increased aggressiveness, revealing non-specific role of serotonin in the control of aggressive behavior, and also provides information about the inhibition of serotonergic activity under repeated experience of aggression.
The total equivalent mass of the medical support system and safety system in the astronaut’s life support system is analyzed. For a prospective expedition to Mars, the life support systems (without ...the greenhouse) account for 27.4% of the mass and 26.4% of the volume of the habitable modules.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Whole-transcriptome data were used to study the changes in expression of genes coding proteins involved in the calcium regulation processes in the hippocampus of male mice with symptoms of depression ...caused by chronic social defeat stress. Cacna1g, Cacnb3, Camk1g, Camk2d, Camk2n2, Caly, Caln1, S100a16, and Slc24a4 genes were upregulated in the hippocampus of depressed mice compared to a control, while Cacna2d1, Cacng5, Grin2a, and Calm2 were downregulated. The greatest number of significant correlations was observed between the expression level of Calm2, which showed the highest transcriptional activity, and other differentially expressed genes. Calcium signaling in the hippocampus was assumed to be disrupted in mice exposed to chronic social defeat stress. The involvement of Calm2, Camk1g, Camk2d, and Camk2n2 genes in the process is discussed.
Whole-transcriptome data were used to study the changes in expression of genes coding proteins involved in the calcium regulation processes in the hippocampus of male mice with symptoms of depression ...caused by chronic social defeat stress.
Cacna1g
,
Cacnb3
,
Camk1g
,
Camk2d
,
Camk2n2
,
Caly
,
Caln1
,
S100a16
, and
Slc24a4
genes were upregulated in the hippocampus of depressed mice compared to a control, while
C-acna2d1
,
Cacng5
,
Grin2a
, and
Calm2
were downregulated. The greatest number of significant correlations was observed between the expression level of
Calm2
, which showed the highest transcriptional activity, and other differentially expressed genes. Calcium signaling in the hippocampus was assumed to be disrupted in mice exposed to chronic social defeat stress. The involvement of
Calm2
,
Сamk1g
,
Camk2d
, and
Camk2n2
genes in the process is discussed.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We present new low-frequency observations of the nearby radio galaxy Fornax A at 154 MHz with the Murchison Widefield Array, microwave flux-density measurements obtained from WMAP and Planck data, ...and gamma-ray flux densities obtained from Fermi data. We also compile a comprehensive list of previously published images and flux-density measurements at radio, microwave and X-ray energies. A detailed analysis of the spectrum of Fornax A between 154 and 1510 MHz reveals that both radio lobes have a similar spatially averaged spectral index, and that there exists a steep-spectrum bridge of diffuse emission between the lobes. Taking the spectral index of both lobes to be the same, we model the spectral energy distribution of Fornax A across an energy range spanning 18 orders of magnitude, to investigate the origin of the X-ray and gamma-ray emission. A standard leptonic model for the production of both the X-rays and gamma-rays by inverse-Compton scattering does not fit the multiwavelength observations. Our results best support a scenario where the X-rays are produced by inverse-Compton scattering and the gamma-rays are produced primarily by hadronic processes confined to the filamentary structures of the Fornax A lobes.
Type III solar radio bursts are the Sun's most intense and frequent nonthermal radio emissions. They involve two critical problems in astrophysics, plasma physics, and space physics: how collective ...processes produce nonthermal radiation and how magnetic reconnection occurs and changes magnetic energy into kinetic energy. Here magnetic reconnection events are identified definitively in Solar Dynamics Observatory UV-EUV data, with strong upward and downward pairs of jets, current sheets, and cusp-like geometries on top of time-varying magnetic loops, and strong outflows along pairs of open magnetic field lines. Type III bursts imaged by the Murchison Widefield Array and detected by the Learmonth radiospectrograph and STEREO B spacecraft are demonstrated to be in very good temporal and spatial coincidence with specific reconnection events and with bursts of X-rays detected by the RHESSI spacecraft. The reconnection sites are low, near heights of 5-10 Mm. These images and event timings provide the long-desired direct evidence that semi-relativistic electrons energized in magnetic reconnection regions produce type III radio bursts. Not all the observed reconnection events produce X-ray events or coronal or interplanetary type III bursts; thus different special conditions exist for electrons leaving reconnection regions to produce observable radio, EUV, UV, and X-ray bursts.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Midbrain raphe nuclei (MRNs) contain a large number of serotonergic neurons associated with the regulation of numerous types of psychoemotional states and physiological processes. The aim of this ...work was to study alterations of the MRN transcriptome in mice with prolonged positive or negative fighting experience and to identify key gene networks associated with the regulation of serotonergic system functioning. Numerous genes underwent alterations of transcription in the MRNs of male mice that either manifested aggression or experienced social defeat in daily agonistic interactions. The expression of the
gene encoding the rate-limiting enzyme of the serotonin synthesis pathway correlated with the expression of many genes, 31 of which were common between aggressive and defeated mice and were downregulated in the MRNs of mice of both experimental groups. Among these common differentially expressed genes (DEGs), there were genes associated with behavior, learning, memory, and synaptic signaling. These results suggested that, in the MRNs of the mice, the transcriptome changes associated with serotonergic regulation of various processes are similar between the two groups (aggressive and defeated). In the MRNs, more DEGs correlating with
expression were found in defeated mice than in the winners, which is probably a consequence of deeper
downregulation in the losers. It was shown for the first time that, in both groups of experimental mice, the changes in the transcription of genes controlling the synthesis and transport of serotonin directly correlate with the expression of genes
and
, which control the synthesis of corticotrophin- and thyrotropin-releasing hormones. Our findings indicate that CRH and TRH locally produced in MRNs are related to serotonergic regulation of brain processes during a chronic social conflict.
There is experimental evidence that chronic social defeat stress is accompanied by the development of an anxiety, development of a depression-like state, and downregulation of serotonergic genes in ...midbrain raphe nuclei of male mice. Our study was aimed at investigating the effects of chronic lithium chloride (LiCl) administration on anxiety behavior and the expression of serotonergic genes in midbrain raphe nuclei of the affected mice. A pronounced anxiety-like state in male mice was induced by chronic social defeat stress in daily agonistic interactions. After 6 days of this stress, defeated mice were chronically treated with saline or LiCl (100 mg/kg, i.p., 2 weeks) during the continuing agonistic interactions. Anxiety was assessed by behavioral tests. RT-PCR was used to determine Tph2, Htr1a, Htr5b, and Slc6a4 mRNA expression. The results revealed anxiolytic-like effects of LiCl on social communication in the partition test and anxiogenic-like effects in both elevated plus-maze and social interaction tests. Chronic LiCl treatment upregulated serotonergic genes in midbrain raphe nuclei. Thus, LiCl effects depend on the treatment mode, psycho-emotional state of the animal, and experimental context (tests). It is assumed that increased expression of serotonergic genes is accompanied by serotonergic system activation and, as a side effect, by higher anxiety.
Chronic social defeat stress leads to the development of anxiety- and depression-like states in male mice and is accompanied by numerous molecular changes in brain. The influence of 21-day period of ...social stress on ribosomal gene expression in five brain regions was studied using the RNA-Seq database. Most Rps, Rpl, Mprs, and Mprl genes were upregulated in the hypothalamus and downregulated in the hippocampus, which may indicate ribosomal dysfunction following chronic social defeat stress. There were no differentially expressed ribosomal genes in the ventral tegmental area, midbrain raphe nuclei, or striatum. This approach may be used to identify a pharmacological treatment of ribosome biogenesis abnormalities in the brain of patients with “ribosomopathies.”
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FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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