Metabotropic receptor of the group I of the 5th subtype (ImGluR5) in honeybee associative olfactory learning

The work deals with study of character of localization in the honeybee head ganglion of metabotropic receptor ImGluR5 and its role in memory formation. With aid of pharmacological method (injections of antisense oligonucleotide and of selective receptor agonist and antagonist) and of behavioral criterion (formation and testing of preservation in memory of conditioned alimentary reflex for olfactory stimulus), there has been shown for the first time the participation of the studied receptor in formation of the honeybee long-term memory. By using the immunohistochemical method, there is first revealed the predominant expression of the ImGluRS receptor in the mushroom body Canyon cells responsible for the insect integrative activity. The present study, together with the previous ones, allows concluding about the presence in the honeybee head ganglion of the group I of metabotropic glutamate receptors with two subtypes 1 and 5 (ImGluRl,5) that have similar with mammals pharmacological properties favoring preservation of the individually acquired experience in the long-term memory.     

Granulocyte-CSF induced inflammation-associated cardiac thrombosis in iron loading mouse heart and can be attenuated by statin therapy

Background  

Granulocyte colony-stimulating factor (G-CSF), a hematopoietic cytokine, was recently used to treat patients of acute myocardial infarction with beneficial effect. However, controversy exists as some patients developed re-stenosis and worsened condition post G-CSF delivery. This study presents a new disease model to study G-CSF induced cardiac thrombosis and delineate its possible mechanism. We used iron loading to mimic condition of chronic cardiac dysfunction and apply G-CSF to mice to test our hypothesis.     

Use of bacterial DNA-methylases for structuro-functional analysis of the eukaryotic genome

Bacterial DNA-methylases with known recognition sites (RS) were used as probes for structural-and-functional analysis of eukaryotic genome. Adenine and cytosine DNA-methylases recognizing 4 to 6-member unique and degenerative nucleotide sequences having a symmetrical and asymmetrical structure were used for probing. The use of a set of methylases enabled the selection of a probe that was the most sensitive for the given pathology. Thus, severe hypothyrosis was found to be associated with changes in the acceptor capacity of liver DNA in the heterologous++ methylation reaction as could be evidenced from testing by two probes, CCCC and GAATGC. In the cells of chicken liver hepatoma MC29, the acceptor capacity of DNA during GGA methylation appeared to be altered in the greatest degree. DNA-methylases with degenerative SR are weakly specific probes for the study of structural changes (methylation) of the animal genome.     

Incidence of dominant lethals in the progeny of young male house mice (Mus musculus L.) after exposure to excretory products of mature males of the same species

The influence of biologically active substances of excretory products (EP) of house mouse adult males on reproductive function of young males was studied with the help of the dominant lethal test. Mortality of the progeny and frequency of nonpregnant females were analysed on the 6th and 8th weeks after EP exposure. Preimplantation and postimplantation mortality frequency increased significantly (P less than 0.05) at 6th and 8th weeks after 2 h EP exposure. Frequency of dominant lethals and nonpregnant females is also increased. Thus, inhibition of reproductive function of young males after EP action has been demonstrated. Possible mechanisms of the effects revealed and their importance for house mouse populations are discussed.     

Study of the conditions of activation and stabilization of DNA-methylases from Shigella sonnei 47 during fractionation, purification and storage

A comparative study of activation factors and stabilization conditions of partially purified and individual fractions of DNA-methylases of Shigella sonnei 47 was carried out. The stability of DNA-methylases in the course of storage was examined. The influence of activating factors and stabilization conditions differed significantly depending on the degree of purification and composition of methylase preparations. It was shown that glycerol is ineffective as a stabilizing agent. The activating effect of Ca2+ on Shigella sonnei 47 DNA-methylases was found to be universal, while albumin was shown to exert a more potent stabilizing action. The inactivating effect of proteases on DNA methylation enzymes during storage was demonstrated. A phenomenon of spontaneous fluctuations in the methylating activity of enzymatic preparations of Shigella sonnei 47 upon storage was observed.     

The regulatory effect of dipeptides on cell proliferation in mammalian nerve tissue culture and olfactory associative learning in insects

The study addresses the effects of dipeptides AspPro and AspSer and their constituent amino acids (aspartic acid—Asp, proline—Pro, and serine—Ser) on proliferative activity of rat brain cortical and subcortical tissue explants and functional activity of the honeybee central nervous system. The area index was calculated as a ratio of the total explant area to the area of its central zone. The number of bees which exhibited a conditioned response, namely proboscis extension towards the odorized solution, 1 min (short-term memory) and 180 min (long-term memory) after single trial learning was also measured. Both dipeptides, as well as aspartate itself, stimulated the expansion of the growth zone of rat subcortical tissue explants and increased the number of bees that retained in their short-term/long-term memory the acquired conditioned response, regardless of the effect of the second component of the dipeptide. The similarity of these effects suggests that common mechanisms of reception and signal transduction have evolved in insects and mammals, and this requires further study.     

The effect of salinity on the grazing rate and survival of Daphnia magna females adapted to different salinities

Aquatic Ecology - The cladoceran Daphnia magna inhabits lakes with salinities up to 10 g L?1. We compared the effects of different salinities (up to 9 g L?1) on the...