Neuroimaging Study of Alpha and Beta EEG Biofeedback Effects on Neural Networks

Neural networks interaction was studied in healthy men (20–35 years old) who underwent 20 sessions of EEG biofeedback training outside the MRI scanner, with concurrent fMRI–EEG scans at the beginning, middle, and end of the course. The study recruited 35 subjects for EEG biofeedback, but only 18 of them were considered as “successful” in self-regulation of target EEG bands during the whole course of training. Results of fMRI analysis during EEG biofeedback are reported only for these “successful” trainees. The experimental group (N?=?23 total, N?=?13 “successful”) upregulated the power of alpha rhythm, while the control group (N?=?12 total, N?=?5 “successful”) beta rhythm, with the protocol instructions being as for alpha training in both. The acquisition of the stable skills of alpha self-regulation was followed by the weakening of the irrelevant links between the cerebellum and visuospatial network (VSN), as well as between the VSN, the right executive control network (RECN), and the cuneus. It was also found formation of a stable complex based on the interaction of the precuneus, the cuneus, the VSN, and the high level visuospatial network (HVN), along with the strengthening of the interaction of the anterior salience network (ASN) with the precuneus. In the control group, beta enhancement training was accompanied by weakening of interaction between the precuneus and the default mode network, and a decrease in connectivity between the cuneus and the primary visual network (PVN). The differences between the alpha training group and the control group increased successively during training. Alpha training was characterized by a less pronounced interaction of the network formed by the PVN and the HVN, as well as by an increased interaction of the cerebellum with the precuneus and the RECN. The study demonstrated the differences in the structure and interaction of neural networks involved into alpha and beta generating systems forming and functioning, which should be taken into account during planning neurofeedback interventions. Possibility of using fMRI-guided biofeedback organized according to the described neural networks interaction may advance more accurate targeting specific symptoms during neurotherapy.     

Glandular trichomes of <Emphasis Type="Italic">Tussilago Farfara</Emphasis> (Senecioneae,Asteraceae)

Main conclusion

The glandular trichomes are developed on the aerial organs of Tussilago farfara ; they produce phenols and terpenoids. Smooth endoplasmic reticulum and leucoplasts are the main organelles of the trichome secretory cells. The aim of this study was to characterise the morphology, anatomy, histochemistry and ultrastructure of the trichomes in Tussilago farfara as well as to identify composition of the secretory products. Structure of trichomes located on the peduncles, bracts, phyllaries, and leaves were studied by light and electron microscopy. The capitate glandular trichomes consist of a multicellular head and a biseriate long stalk. Histochemical tests and fluorescence microscopy reveal phenols and terpenoids in the head cells. During secretory stage, the head cells contain smooth and rough endoplasmic reticulum, Golgi apparatus, diversiform leucoplasts with opaque contents in lamellae, chloroplasts, mitochondria, and microbodies. In the capitate glandular trichomes of T. farfara subcuticular cavity is absent, unlike glandular trichomes in other Asteraceae species. For the first time, content of metabolites in the different vegetative and reproductive organs as well as in the isolated capitate glandular trichomes was identified by GC–MS. Forty-five compounds, including organic acids, sugars, polyols, phenolics, and terpenoids were identified. It appeared that metabolite content in the methanol extracts from peduncles, bracts and phyllaries is biochemically analogous, and similar to the metabolites from leaves, in which photosynthesis happens. At the same time, the metabolites from trichome extracts essentially differ and refer to the above-mentioned secondary substances. The study has shown that the practical value of the aerial organs of coltsfoot is provided with flavonoids produced in the capitate glandular trichomes.

     

Morphologic changes in the pineal gland of rats exposed to continuous darkness

We examined the pineal structure of rats exposed to constant darkness (DD) at light microscopic level. Two groups of rats were exposed to 12:12 light/dark cycle (LD) or DD from their prenatal ontogenesis and then for 3 months after birth. The gland structure of DD rats was observed to have an active appearance. Some of the observed pinealocytes with light nuclei from DD rats were determined to contain double nucleoli. Nuclear area and perimeter of both dark and light types were greater in rats kept in DD than in LD. Rats exposed to DD had more cells with light nuclei and lesser cells with dark ones than rats kept in LD. No significant differences in nuclear characteristics of intermediate type were found between rats kept in LD and those kept in DD. The activity of mammalian pineal can be altered by light conditions to which the animal is exposed.     

HSP70-inducible hNIS-IRES-eGFP reporter imaging: response to heat shock

A retroviral vector pQHSP70/hNIS-IRES-eGFP (pQHNIG70) was constructed containing the hNIS-IRES-eGFP dual-reporter genes under the control of an inducible human heat shock protein (HSP)70 promoter and RG2-pQHSP70/hNIS-IRES-eGFP (RG2-pQHNIG70) transduced cells were generated. Heat-induced expression of both reporter genes in RG2-pQHNIG70 cells was validated by enhanced green fluorescent protein (eGFP) fluorescence-activated cell sorter, in vitro radiotracer assays, and immunoblot and immunocytochemistry. A 2.2- to 6.1-fold ((131)I(-)), a 6.1- to 14.4-fold ((99m)TcO(4)(-)), and a 5.1- to 39-fold (fluorescence) increase above baseline was observed in response to graded hyperthermia (39-43 degrees C). Increases in eGFP fluorescence and radiotracer uptake were first noted at 6 hours, reached a maximum at 24 hours, and fell toward baseline at 72 hours. A stable ratio of radiotracer uptake to eGFP fluorescence and to heat shock protein (HSP)70 protein was demonstrated over a wide range of expression levels, induced by different levels of heating. We also demonstrate that the local application of heat on RG2-pQHNIG70 xenografts can effectively induce hNIS and eGFP gene expression in vivo and that this expression can be efficiently visualized by fluorescence, scintigraphic, and micro-positron emission tomography imaging. Endogenous HSP70 protein and reporter expression was confirmed by postmortem tissue evaluations (immunoblot and immunohistochemistry). The pQHNIG70 reporter system can be used to study stress and drug responses in transduced cells and tissues.     

Iron-shortage-induced increase in citric acid content and reduction of cytosolic aconitase activity in Citrus fruit vesicles and calli

Aconitase, which catalyses the conversion of citrate into isocitrate, requires Fe for its activity. The yeast and animal enzyme loses its enzymatic activity under Fe shortage and binds to RNA of genes involved in Fe homeostasis, altering their expression. Thus, the enzyme provides a regulatory link between organic acid metabolism and Fe cellular status. Roots and leaves of Fe-deficient plants show induction in organic acids, especially citrate. Although no RNA-binding activity has been so far demonstrated for the plant aconitase, whether alternations in enzyme activity by Fe could play a role in this induction remain unanswered. This question was investigated in lemon fruit [ Citrus limon (L.) Burm var Eureka ], characterized by the accumulation of citrate to about 0.3 M in the juice vesicles cells (pulp). Calli and isolated juice vesicles showed two- to three-fold induction in citrate level when subjected to Fe shortage. The mRNA level of aconitase exhibited no changes under reduced Fe concentrations. Analysis of aconitase isozymes demonstrated that out of two aconitase isozymes, typically detected in citrus fruit, only the cytosolic form displayed a reduced activity under low Fe concentrations. Our data support the notion of a limited Fe-availability-induced reduction in cytosolic aconitase, resulting in a slower rate of citrate breakdown and a concomitant increase in citrate levels.     

A polymer with a backbone of 3-deoxy-D-glycero-D-galacto-non-2-ulopyranosonic acid, a teichuronic acid, and a beta-glucosylated ribitol teichoic acid in the cell wall of plant pathogenic Streptomyces sp. VKM Ac-2124.

Structures of cell wall anionic polymers of the strain Streptomyces sp. VKM Ac-2124, a causative agent of potato scab, which is phylogenetically the closest to plant pathogenic species S. setonii and S. caviscabies, were studied. The strain contains three anionic glycopolymers, viz., a teichuronic acid with a disaccharide repeating unit -->6)-alpha-d-Glcp-(1-->4)-beta-d-ManpNAc3NAcA-(1-->, a beta-glucosylated polymer of 3-deoxy-d-glycero-d-galacto-non-2-ulopyranosonic acid (Kdn), and a beta-glucosylated 1,5-poly(ribitol phosphate). The strain studied is the second representative of plant pathogenic streptomycetes inducing potato scab disease, the cell wall anionic polymers of which were shown to contain a Kdn-polymer. Presumably, the presence of Kdn-containing structures in the surface regions of pathogens is essential for their efficient attachment to host plant cells.     

Limited Proteolysis of Bacillus thuringiensis CryIG and CryIVB δ-Endotoxins Leads to Formation of Active Fragments That Do Not Coincide with the Structural Domains

Bacillus thuringiensis true toxins consist of three domains: the N-terminal, -helical domain followed by two -structural domains. Their limited proteolysis does not proceed at the domain boundaries, but is directed to the loops within the domains. There are at least two patterns of the limited proteolysis of true toxins. The first pattern, observed for CryIA and CryIVD -endotoxins, results in the proteolysis of the loops connecting -strands of the second domain. The second pattern, detected for CryIG and CryIVB proteins, consists in the cleavage of the loop connecting the fifth and the sixth -helixes of the first domain. The choice between the routes depends on the size, sequence, and dynamics of the loop that define its accessibility to a proteinase. Bioassay of CryIG and CryIVB -endotoxin fragments indicates that only two -helixes, the sixth and the seventh within the first domain, followed by the two -structural domains are sufficient for the insecticidal activity.     

Limited Proteolysis of Bacillus thuringiensis CryIG and CryIVB δ-Endotoxins Leads to Formation of Active Fragments That Do Not Coincide with the Structural Domains

Bacillus thuringiensis “true” toxins consist of three domains: the N-terminal, α-helical domain followed by two β-structural domains. Their limited proteolysis does not proceed at the domain boundaries, but is directed to the loops within the domains. There are at least two patterns of the limited proteolysis of “true” toxins. The first pattern, observed for CryIA and CryIVD δ-endotoxins, results in the proteolysis of the loops connecting β-strands of the second domain. The second pattern, detected for CryIG and CryIVB proteins, consists in the cleavage of the loop connecting the fifth and the sixth α-helixes of the first domain. The choice between the routes depends on the size, sequence, and dynamics of the loop that define its accessibility to a proteinase. Bioassay of CryIG and CryIVB δ-endotoxin fragments indicates that only two α-helixes, the sixth and the seventh within the first domain, followed by the two β-structural domains are sufficient for the insecticidal activity.     

Sudies of O-specific polysaccharide chains of Pseudomonas solanacearum lipopolysaccharides consisting of structually different repeating units.

The structure of the O-antigenic ploysaccharide chains of lipopolysaccharides of a number of Pseudomonas solanacearum strains were elucidated mainly with the help of methylation analysis and ¹³CNMR spectroscopy, including a computer-assisted ¹³CNMR-based analysis. Six structually distinct but related polysaccharides were identified. They have a backbone which is built up of three -rhammoyranosyl resides and one 2-acetamido-2-deoxy- -glucopyranosyl residue, and is unsubtituted or substituted with a residue of -xylopyranose or -rhamnopyranose as a monosaccharide side chain. The lipopolysaccharides of most of the strains contain polysaccharide chains consisting of at least two structually different types of repeating units. Three of the polysaccharides are common to more than one strain.     

Correction: NPP-ID: Non-Pollen Palynomorph Image Database as a research and educational platform

Vegetation History and Archaeobotany -