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Biomedical subjects

V V Sherstnev

Publications and source records attributed to V V Sherstnev.

At least 19 recordsLinked to original sources
PubMed2006

Hexapeptides HLDF-6 and PEDF-6 restore memory in rats after chronic intracerebroventricular treatment with beta-amyloid peptide Abeta(25-35).

Effects of homologous peptides HLDF-6 and PEDF-6 on behavior of animals with experimental Alzheimer's disease induced by chronic intracerebroventricular administration of beta-amyloid peptide Abeta(25-35) were studied in the zoosocial recognition test and Morris water maze. Peptides HLDF-6 and PEDF-6 possessed neuroprotective activity and counteracted the toxic effect of Abeta(25-35). Peptides HLDF-6 and PEDF-6 mainly improved long-term memory and working memory, respectively.

Amyloid beta-Peptides↗
PubMed2006

Biochemical markers of apoptosis in different parts of the brain during learning.

Caspase-3 activity and the levels of DNA fragments of 200-600 and >4000 b.p. were estimated in the cerebellar vermis, the hippocampus, and the prefrontal cortex of the brains of adult rats four and 24 months after training to extinction of the acoustic startle reaction and conditioned fear. Differently timed changes in the levels of biochemical markers of apoptosis were seen to different extents in these brain areas after training. These changes were characterized by a decrease in caspase-3 activity in the cerebellar vermis and the hippocampus, with decreases in DNA fragmentation in the hippocampus and cerebral cortex and increases in measures of programmed cell death in the hypothalamus. These experimental data support the view that the apoptosis of cells in the mature brain is involved in the mechanisms of learning and memory.

Acoustic Stimulation↗
PubMed2005

In vivo investigation of genome activity and synaptic plasticity of neurons in snails during learning.

The present report describes in vivo investigations of genome activity and its role in the mechanisms forming long-term synaptic plasticity in defensive behavior command neuron LPl1 during the acquisition of nociceptive sensitization by common snails. Transcription processes were recorded using SYTO 16, a specific fluorescent indicator of DNA activity, along with in vivo computer image analysis. Studies in control snails showed that application of nociceptive stimuli to the head led to biphasic changes in the bioelectrical responses of neurons to tactile and chemical stimulation--depression of responses in the short-term stage (during the 1 h after training) and their facilitation during the long-term stage of sensitization (more than 24 h). There were marked increases in fluorescence over the nucleus of the command neuron stained with SYTO 16 at 15-20 min from the start of training, this lasting 4-5 h. Acquisition of sensitization in the presence of the RNA synthesis inhibitor actinomycin D (20 microM) to the neuron led to the complete elimination of changes in fluorescence and synaptic facilitation in the responses of LPl1 to sensory stimulation in the long-term stage of sensitization but had no effect during the short-term stage of sensitization. Actinomycin D given 30 min after the end of acquisition of sensitization (1 h after the start) had no effect on the dynamics of fluorescence or synaptic facilitation. Thus, the acquisition of nociceptive sensitization is accompanied by a rapid (within 15-20 min) activation of the DNA of neuron LPl1 and subsequent (about 1 h) display of long-term synaptic facilitation. Induction of both processes was suppressed by the RNA synthesis inhibitor over a relatively short time period--1 h from the moment at which training started.

Action Potentials↗
PubMed2005

[Involvement of autoimmune mechanisms in development of ischemic brain damage].

Autoimmune processes take place during an acute phase of brain injury as well as during chronic vascular diseases. Cryoglobulinemia is a nonspecific marker of long-term stimulation of the immune system which reflects duration of autoimmune sensitization. It is characterized by production of abnormal temperature-dependent immunoglobulins named cryoglobulins. The highest cryoglobulinemia was found in patients with atherothrombotic stroke that corresponds to the results of previous studies reporting the greatest level of neurospecific antibodies during slow atherothrombosis development. It is shown that cryoglobulinemia is an important factor in pathogenesis of stroke which contributes to microcirculatory and hemorheological disorders, increases blood viscosity and results in the development of immunocomplex endovasculitis of small brain blood vessels in the ischemic lesion.

Autoantibodies↗
PubMed2004

Autoimmune responses to amyloid structures of Abeta(25-35) peptide and human lysozyme in the serum of patients with progressive Alzheimer's disease.

We have found an increased level of serum antibodies to the prefibrillar structures of both Abeta(25-35) peptide and human lysozyme in Alzheimer's disease (AD) patients compared to age-matched controls, indicating that autoimmunity is implicated in AD. In the serum of AD patients with a long-term duration (>15 years) the titer of serum antibodies to aggregates of Abeta(25-35) peptide increased by approximately 5-fold, whilst the antibody titer to lysozyme protofilaments decreased by approximately 8-fold compared to patients with AD duration of <5 years. The content of immunoglobulins of the A, G and M types declined, particularly in AD duration of >15 years. An increase in the concentration of immune complexes and higher lysozyme activity was detected in the serum of all patients and this was suggestive of an inflammatory reaction. We propose that the autoimmune response to different amyloid structures in AD can be viewed as a clearance pathway targeting amyloid development. Autoimmune response can be exploited as a marker of ongoing protein aggregation and hence be used as a diagnostic feature of AD.

Aged↗
PubMed2004

Specificity of postsynaptic excitations of different sensory modality in neurons of edible snail during learning.

The development of sensitization in edible snails during intracellular injection of oligonucleotides specifically inhibiting C/EBP transcription factors results in selective suppression of synaptic facilitation in responses of LPl1 neurons evoked by chemical stimulation of the head. At the same time, facilitation of the responses to tactile stimulation of the head or foot developed as in control sensitized animals. The data are interpreted from the viewpoint of P. K. Anokhin hypothesis that integrative function of cerebral neurons involved in construction of biologic functional systems is based on peculiar pre- and postsynaptic chemical processes selectively projected onto the genome of neural cell.

Animals↗
PubMed2004

Selective effects of antibodies to protein SMP-69 on the activity of defensive behavior command neurons in the common snail.

The effects of antibodies to the serotonin-modulated protein SMP-69 on the activity of defensive behavior command neurons LP11 and RP11 in semi-intact preparations from common snails were studied. Antibody to SMP-69 increased membrane excitability and facilitated neuron responses to chemical sensory stimulation by application of dilute quinine solution to the animal's head, these effects being seen at 1-1.5 h. The synaptic effects of the antibodies were specific, as they had no influence on responses induced by tactile stimulation of the head. The neuronal effects of antibody SMP-69 were similar to changes in the activity of cells LP11 and RP11 induced by serotonin and cAMP, and to changes seen when snails acquired nociceptive sensitization. It seems likely that a protein homologous to mammalian SMP-69 is involved in the mechanisms controlling excitability and long-term specific plasticity of the synaptic inputs to neurons LP11 and RP11 from chemoreceptors on the snail's head.

Action Potentials↗
PubMed2004

[Vital investigation of the genome activity and neuronal synaptic plasticity in snail in the course of learning].

Vital investigation of genome activity and its role in mechanisms of long-term synaptic plasticity formation were studied in LP11 neuron (command neurone of defence behaviour) during sensitisation (simple form of learning) in semi-intact preparation of snail Helix lucorum. Genome activity was investigate by means of specific fluorescent dye SYTO 16 and image analysis system. It was found that application of sensitizing stimulation (10% quinine solution) onto the snail head initiate two-phase changes in neural responses evoked by tactile or chemical stimulation. Depression of neural responses was obtained during short-term phase (during 1 hour after sensitization) and facilitation of neural responses--during long-term phases (over 1 hour). At the same time (15-20 min after learning), a significant increase in SYTO 16 fluorescent level was found in nucleus site LP11 neurone. Initial SYTO 16 fluorescence level was registered in 4-5 hours after sensitization. If the sensitization was produced during actinomycin D application (inhibitor of RNA synthesis, 20 microM) then facilitation of neural responses evoked by sensory stimulation were suppressed during long-term phase of sensitization and was the same as in control sensitized snails during short-term phase of learning. Increase in SYTO 16 fluorescence level in nucleus region site of LP11 neurone was completely prevented in sensitization during actinomycin D application. If actinomycin D was applied 30 min after sensitization (1 hour after first sensitizing stimulation) then synaptic facilitation and fluorescent dynamics was the same as in control sensitized snails. Our experimental data showed that nociceptive sensitization development was followed by quick (15-20 min) DNA activation and long-term synaptic facilitation (1 hour after sensitization), while induction of the processes was suppressed by inhibitor of RNA synthesis during short time interval (during 1 hour of learning).

Animals↗
PubMed2004

[Protein HLDF and antibodies to it as molecular pathogenetic factors and new markers of acute cerebral blood circulation disturbances].

Clinic-experimental complex investigation and ELISA determination of protein HLDF as also primary antibodies (Abs) to HLDF values in blood and cerebro-spinal fluid (CSF) of patients with hypertensive crises and acute aterotrombotic ischemic stroke were performed. Statistically improved difference in serum HLDF and Abs content in examined patients in comparison with age-matched controls as also significant intergroup's differences in protein and Abs dynamic content were determined. Correlation between content and dynamics of investigated factors in CSF and blood serum with determined clinical and instrumental parameters was revealed. Pathogenetic and prognostic significance of revealed changes in molecular factors was viewed.

Acute Disease↗
PubMed2003

Heterochronous involvement of neurotrophic factors in the neurochemical organization of learning and memory processes in adult organisms.

Studies were performed on the involvement of neurotrophic factors in the neurochemical mechanisms of the integrative functions of the brain. The effects of various intrahippocampal doses of antibodies to neurotrophic factors--protein S100 and lectin CSL--were studied on the formation, retention, and reproduction of a habituated acoustic startle response and conditioned fear in adult rats. S100b contents in the hippocampus, hypothalamus, frontal cortex, and cerebellar hemispheres and vermis, and in the basal nuclei were measured in rat brains 0.5, 1, 2, 4, 6, 8, 24, and 48 h after long-term habituation to the startle response. Antibodies to neurotrophic factors had selective and dose-dependent effects on the different memory and learning processes underlying these types of behavior. Changes in S100b in brain structures were seen, which were specific in terms of quantitative levels and dynamics, after acquisition of the behavioral habit. The results obtained here, along with previously reported data on the effects of antibodies to S100b and CSL given into the cerebellum, are discussed as experimental support for the hypothesis of the heterochronous neurochemical organization of integrative brain activity.

Analysis of Variance↗
PubMed2003

S100B protein in pro- and antiapoptotic doses produces different effects on defensive behavior in adult rats.

We studied the effects of S100b protein in doses stimulating (500 and 50 ng) or inhibiting (5 ng) apoptosis in nerve cells on acquisition, retention, and retrieval of extinction of the acoustic startle response and conditioned fear in adult rats. After application to the vermis of the cerebellum S100b protein in doses of 500 and 50 ng impaired, while in a dose of 5 ng facilitated acquisition of both forms of defensive behavior. Different behavioral effects of S100b protein are probably related to its pro- and antiapoptotic effects on cerebellar cells relevant to the studied forms of behavior. Our results suggest that regulators of apoptosis are involved in the mechanisms of learning and memory.

Acoustic Stimulation↗
PubMed2003

[Selective effect of the antibody to protein SMP-69 on activity of the defence behavior command neurons in grape snail].

Effects of antibody against serotonin-modulated protein SMP-69 on defence behavior command neurons L-RP11 were studied in semi-intact preparation of snail Helix lucorum. An increase in membrane excitability as well as selective facilitation of neural responses evoked with chemical sensory stimulation of the snail head (0.25-0.5% quinine solution) were determined 1-1.5 hours after antibody application to the neurons. The antibody did not change neural responses evoked with tactile stimulation of the snail head. These effects were similar to those found in L-RP11 neurons after serotonin or cAMP applications as well as after nociceptive sensitization of the snail. It was suggested that protein homologically related the SMP-69 in mammalians was involved in mechanisms of excitability as well as long-term specific plasticity regulation of L-RP11 neurons synaptic inputs from the head chemoreceptors in snail Helix lucorum.

Action Potentials↗
PubMed2002

Effects of antibodies against protein S100b on synaptic transmission and long-term potentiation in CA-1 hippocampal neurons in rats.

Effects of idiotypic and antiidiotypic antibodies against protein S100b on synaptic transmission and long-term potentiation of CA1 pyramidal neurons in rat hippocampus were studied. Idiotypic antibodies against protein S100b inhibited synaptic transmission from Schaffer collateral axons to pyramidal neurons, but had no effect on neuronal responses to antidromic stimulation. Antiidiotypic antibodies against protein S100b facilitated neuronal responses to orthodromic stimulation. Idiotypic antibodies against protein S100b suppressed changes in neuronal responses to orthodromic stimulation during long-term potentiation, while antiidiotypic antibodies facilitated these effects. Our findings suggest that the effects of idiotypic and antiidiotypic antibodies to protein S100b are associated with their regulatory influences on synaptic transmission. These mechanisms differ from mechanisms of synaptic plasticity involved in long-term potentiation.

Animals↗
PubMed2002

[Neurotrophic factors and autoantibodies to them as molecular predictors of cerebral dysfunctions].

A complex of clinical and immunochemical studies was made in patients with chronic brain ischemia and ischemic stroke and in neonatal infants with CNS dysfunctions and retarded intrauterine development. Enzyme immunoassay was used to measure the levels of brain proteins with trophic properties--S100b, the major protein myelin, lectins CSL, R1, and the levels of primary and antiidiotypic antibodies to these proteins in the biological fluids of the patients. The findings suggest that the study brain proteins and autoimmune processes against these factors are involved in the mechanisms of the pathogenesis of the diseases in question and they enable changes and variations in the levels of neurotropic factors and their autoantibodies to be considered as predictors of brain ischemia and perinatal cerebral lesions.

Autoantibodies↗
PubMed2001

[Heterochronic effects of neurotrophic factors in neurochemical organization of learning and memory in the adult organism].

Following elaboration of long-term habituation to a startle-response, antibodies to neurotrophic factor protein S100b exerted selective and dose-dependent influence on different learning processes and memory of learned behavioural patterns in adult rats. S100b increased at all stages of behavioural skill development in hippocampus, hypothalamus, frontal cortex, cerebellar hemispheres and vermis, basal ganglia.

Acoustic Stimulation↗
PubMed2000

A tunable single-mode 3.2 microm laser based on an InAsSb/InAsSbP double heterostructure with drive-current tuning range of 10 cm(-1).

A new type of semi-conductor laser with composition InAsSb/InAsSbP is described. This laser was produced for the absorption spectroscopy of atmospherically important molecules in the 3100 cm(-1) region and tested using a closed-cycle He-cryostat in the temperature range 30-80 K. The optimal characteristics of the laser were found to be a heatsink temperature of 62 K and a drive current range of 50-350 mA. Under these conditions, the laser emits single-mode radiation in an exceptionally large wavenumber range of > 10 cm(-1). To test the laser, several experiments were carried out in which the rovibrational absorption spectra of CH3Cl, NH3, OCS and H2O were measured.

Gases↗
PubMed1999

[Involvement of neurotrophic factors in central mechanisms of behavior in adult animals].

The effect of antibodies against some neurotrophic factors (S-100b protein, CSL, etc.) on elaboration, storage, and retrieval of acoustic startle habituation and concomitant freezing behaviour, was found to be dose-dependent in adult rats. Thus, the 5-mcg dose impaired the consolidation and/or storage process, whereas 2 mcg only impaired the storage of long-term acoustic startle habituation, and 0.5 mcg exerted no effect at all. The habits retrieval displayed no dependence on the antibodies effect.

Acoustic Stimulation↗