Mechanism of the suppression of the spinal pain syndrome by serotonin derivatives

The ability of serotonin derivatives to stimulate cAMP accumulation in isolated nerve terminals and lumbar enlargement of the spinal cord of normal rats was compared. The effect of the compounds on the intensity of spinal pain syndrome was also assessed. It has been established that substitutes injected into NH2-group of serotonin in 5-OH position attenuate the ability to stimulate cAMP accumulation in synaptosomes, with the effect more pronounced with substitutes of larger volume. A certain correlation between the ability of serotonin derivatives to stimulate adenylate cyclase in vivo and in vitro, on the one hand, and their analgetic effect, on the other hand, is suggested.     

Effects of intranasally administered substance P in parkinsonian syndrome]

The effect of intranasal substance P injection on parkinsonian syndrome and the generator of pathologically enhanced excitation (GPEE) in caudate nuclei (CN) was investigated. MPTP or reserpine administration in old rats induced oligokinesia, rigidity and tremor followed by the high amplitude slow and rapid waves in both CN. The bilateral intranasal injection of substance P (25 micrograms/kg) resulted in an increase in motor activity and almost completely abolished the rigidity and tremor. The reduction of extrapyramidal symptoms was considered as a result of the inhibition of GPEE in CN. The possibility of substance P entry from nasal cavity into the brain was discussed. The changes of the substance P balance in nigrostriatal system was suggested to be on of the pathogenetic links of parkinsonian syndrome.     

Prolongation of sleep following creation of a generator of pathologically enhanced excitation in the orbital cortex

Acute experiments on cats showed that injection of tetanus toxin into the orbital cortex (which destroys various types of inhibition) resulted in the formation of a local generator of pathologically enhanced excitation in this cortex area. Chronic experiments showed that cats with such a generator in the orbital cortex developed pathological changes of sleep, expressed in reduction of the duration of wakefulness and development of the slow-wave and paradoxical sleep phases being, retained. The results of this investigation confirm the view on the participation of the orbitofrontal cortex in sleep induction. They are in favour of the general conception on the role of the determinant structure in the nervous system activity and the theory of the generator mechanisms of the neuropathological syndromes characterized by the hyperactivity of the system.     

Magnetic interaction of manganese with pheophytin anion-radical and chlorophyll cation-radical in reaction centers of the photosystem II

The influence of Mn on saturation curves of ESR spectra of Ph(-) and P(+)(680) at 1-200K in samples with different content of Mn has been studied. An analysis of these data and those on photoinduced changes of fluorescence yield of chlorophyll leads to the conclusion that the Mn-containing centre in Photosystem 2 is a cluster of 4 Mn atoms, two of which can be replaced by Mg(2+) or any other divalent metal. The distances between Mn Na Ph as well as between Mn and P(680) have been estimated.     

Mechanisms of transmission of excitation grnerated in the orbito-frontal cortex]

Experiments carried out on cats showed that interhemispheric generalization of strychnine spasmodic potentials from the orbito-frontal cortex were mainly brought about by the callosal pathway. In contrast to other projection and association zones of the cortex only the frontal portion of the corpus callosum (the rostrum) and not the whole corpus took part in transmitting strychnine commissures. The results of investigations carried out were consistent with the general conception of the principle of the determining dispatch station (DDS) in the nervous system integration activity. These results reveal that the appearance of the DDS induces secondary excitation foci which fully reproduce tha work regimen of the DDS. Switching of such "mirror" foci representing "the destination stations" from the DDS influence led to the elimination of the activity induced in them.     

Interaction of isolated synaptic vesicles with synaptic contacts in the rat brain

The effects of Mg-ATP, EGTA, EDTA and dicyclohexylcarbodiimide on the changes in the intensity of light scattering were studied in rat brain synaptic vesicles (SV) suspended in saccharose-buffer medium. Specific interactions between SV and isolated synaptic junctional complex were observed in the presence of Mg-ATP and calmodulin. An in vitro model of exocytosis is discussed.     

A new method of assessing anxiety-phobic states in rats]

A new multiparameter method for evaluating anxiety-phobic states in rats is elaborated. The method is based on the ranged scale consisting of parameters which characterize the species-specific rat response to the series of ethologically adequate test-stimuli inducing manifestation of the anxiety-phobic states. The method makes it possible to evaluate individual anxiety-phobic level in rats, to form experimental groups with rats of known individual anxiety-phobic level, to conduct repeated observations in the same animals. The method is easy to perform in laboratory and makes it possible to get the results quickly.     

Phylogeny of the order Rodentia inferred from structural analysis of short retrotransposon B1

A large-scale study of short retroposon (SINE) B1 has been conducted in the genome of rodents from most of the known families of this mammalian order. The B1 nucleotide sequences of rodents from different families exhibited a number of characteristic features including substitutions, deletions, and tandem duplications. Comparing the distribution of these features among the rodent families, the currently discussed phylogenetic relationships were tested. The results of analysis indicated (1) an early divergence of Sciuridae and related families (Aplodontidae and Gliridae) from the other rodents; (2) a possible subsequent divergence of beavers (Castoridae); (3) a monophyletic origin of the group Hystricognathi, which includes several families, such as porcupines (Hystricidae) and guinea pigs (Caviidae); (4) a possible monophyletic origin of the group formed by the remaining families, including six families of mouselike rodents (Myodonta). Various approaches to the use of short retroposons for phylogenetic studies are discussed.     

A new pentanucleotide STR-marker, located in the intron of the ING1 tumor suppressor gene and its allelic polymorphism

DNA samples of unrelated subjects from the Volga-Ural region of Russia were examined to study allele polymorphism of the pentanucleotide repeat (TTGTG)8 localized to an intron of the tumor suppressor gene ING1. STR marker was registered in the EMBL database with the accession number AJ277387. In a sample of 119 individuals, three pentanucleotide alleles consisting of seven, eight, and nine repeated monomers were revealed. The allele frequencies were 0.24, 0.74, and 0.02, respectively. Heterozygosity was 0.45. On the basis of these data, the repeat can be regarded as a polymorphic STR marker for the ING1 gene and used in population and clinical studies.