Involvement of Adult-born and Preexisting Olfactory Bulb and Dentate Gyrus Neurons in Single-trial Olfactory Memory Acquisition and Retrieval.

The production of new neurons and their incorporation into preexisting neuronal circuits occur throughout adulthood in the olfactory bulb and the hippocampal dentate gyrus of the mammalian brain. To determine whether the adult-born neurons are engaged in the acquisition and retrieval of olfactory associative memory, we developed and validated a single-trial olfactory fear conditioning protocol in mice which allows to detect activation of newborn neurons during a specific episode of memory acquisition. Using c-Fos mapping of neuronal activity, we then examined the activation of new and preexisting neurons during training and testing sessions.

Changes in Amnesia Parameters over Time after Long-Term Memory Disruption with Protein Kinase Mζ Inhibitor.

We studied the involvement of protein kinase Mζ (PKMζ) in the mechanisms of amnesia development within 10 days after disruption of conditioned food aversion memory with ZIP (a PKMζ inhibitor). Repeated training performed in 3 days after amnesia induction with ZIP, led to the formation of conditioned food aversion memory, but the number of combined presentations of food and reinforcer stimuli was lower than during the initial training. Repeated training performed in 10 days after amnesia induction also led to memory formation, but the number of combined presentations of the stimuli was similar to that during the initial training.

State of Stress-Marker Organs in Rats after a Single Exposure to Long-Term Stress and Treatment with Lipopolysaccharide.

We studied the effect of LPS on the state of stress-marker organs in rats at various periods after a single exposure to long-term stress on the model of 24-h immobilization. The animals were intraperitoneally injected with LPS in a dose of 100 μg/kg immediately after the negative emotiogenic exposure. Changes in physiological parameters were evaluated 3 h, 1 day, and 8 days after immune stimulation.

Correlation Connections between Individual-and-Typological Features, Indices of Performance of Goal-Directed Activity, and Heart Rate Variability Parameters.

Correlation analysis of the performance of goal-directed activity and heart rate variability parameters in people with different individually-typological features was conducted on the model of endosurgical training. It was found that people with low level of intro-extroversion and neuroticism, but high index of situational anxiety were more successful during goal-directed behavior. The subjects with low level of neuroticism finished the tasks more quickly, both at the beginning and at the end of the observations.

Urokinase receptor and tissue plasminogen activator as immediate-early genes in pentylenetetrazole-induced seizures in the mouse brain.

Epileptogenesis progressively leads to the rearrangement of normal neuronal networks into more excitable ones and can be viewed as a form of neuroplasticity, the molecular mechanisms of which still remain obscure. Here, we studied pentylenetetrazole seizure-induced regulation of genes for plasminogen activator system in the mouse brain. We found that expression of tissue plasminogen activator (tPA) and urokinase receptor (uPAR) mRNA was strongly increased in the mouse cerebral cortex, hippocampus, striatum and amygdala as early as 3 hr after pentylenetetrazole seizures.

Proteins or RNA synthesis inhibitors suppressed induction of amnesia developing under impairment of memory reconsolidation by serotonin receptors antagonist.

Studies have shown that retrieval of long-term memory can cause memory reconsolidation, and impaired reconsolidation leads to amnesia development. However, the mechanisms of amnesia induction due to impaired memory reconsolidation remains poorly described. Using experiments involving grape snails trained to conditioned food aversion, we studied the role of translation and transcription processes and the role of serotonin receptors in the mechanisms of amnesia induction.

Endogenous Opioid Dependence Induced in Rats by Periodic Intake of 5% Ethanol Solution.

We studied the possibility of formation of endogenous opioid dependence in rats during periodic intake of 5% ethanol solution. In the control group, both drinking bottles contained water. In the experimental group, the second bottle was filled with 5% ethanol solution for 12 h per day; in the following 12 h, these rats were deprived of food and ethanol.

Administration of Protein Synthesis Inhibitor before Reminder Reverses Amnesia Induced by Memory Reconsolidation Impairment with 5-HT Receptors Antagonist.

Administration of 5-HT receptor antagonist to snails trained in conditioned food aversion prior to reminding of the conditioning stimulus caused amnesia. At the early period of amnesia (day 3), injections of protein synthesis inhibitor cycloheximide without reminder or reminder alone were ineffective. At the same time, injections of the inhibitor combined with reminder led to memory recovery; this effect in most animals persisted for at least 10 days.

Neurological Deficit and Structural Changes in Lymphoid Structures of the Tracheal Wall in the Immediate Stage of Experimental Hemorrhagic Stroke in Rats with Different Behavioral Activity.

Specific features of neurological deficit and changes in the cellular composition of tracheal lymphoid structures during the immediate stage (day 1) of hemorrhagic stroke were studied in rats with various behavioral parameters. Modeling of hemorrhage in the left caudate nucleus of the brain was followed by the development of motor disturbances in the forelimb use asymmetry test and corner rotation paradigm. These animals preferred to use the left forelimb (ipsilateral to the side of hemorrhage) to lean on the cylinder wall.

Physiology and Pharmacology of Positive Reinforcement.

An original concept of a two-stage mechanism of positive reinforcement is proposed. The first stage, "virtual" reinforcement, is formed in parallel with the action result acceptor when the result is still not achieved. At this stage, the importance of the planned result and the probability of its achievement are assessed.

Mapping the Neural Substrates of Recent and Remote Visual Imprinting Memory in the Chick Brain.

Social attachment formed by filial imprinting in newborn chicks undergoes a process of memory consolidation that involves rearrangement of its neural storage substrates. In the first 3 h after imprinting it depends on the integrity of the intermediate medial mesopallium (IMM) and beyond that time on unidentified memory storage structures dubbed S'. To search for the S' memory system in the chick brain, we mapped and compared patterns of activity induced by retrieval of filial attachment memory before and after this critical transition.

Suppressed neurogenesis without cognitive deficits: effects of fast neutron irradiation in mice.

This study assessed the effects of combined low-dose neutron and γ-ray irradiation on hippocampal neurogenesis and hippocampal-dependent memory. Neural progenitor cell division and survival were evaluated in brain sections and whole hippocampal preparations following head irradiation at a dose of 0.34 Gy for neutron radiation and 0.

Blood Cytokine Profile in Rats with Different Behavioral Characteristics after Metabolic Stress.

Changes in the blood cytokine profile in rats with various parameters of behavior were studied under conditions of 5-day starvation not followed by the recovery period or with subsequent normalization of food intake. Metabolic stress had no effect on the content of most cytokines. The concentration of pro- and anti-inflammatory cytokines in blood plasma of rats was shown to increase significantly by the end of a 5-day recovery period after food deprivation.

The Arc gene: Retroviral heritage in cognitive functions.

Stabilization of neuronal plastic changes is mediated by transient gene expression, including transcription of the activity-regulated cytoskeleton-associated gene (Arc), also known as Arg 3.1. Arc is implicated in several types of synaptic plasticity, including synaptic scaling, long-term potentiation, and long-term depression.

Radiation Induces Distinct Changes in Defined Subpopulations of Neural Stem and Progenitor Cells in the Adult Hippocampus.

While irradiation can effectively treat brain tumors, this therapy also causes cognitive impairments, some of which may stem from the disruption of hippocampal neurogenesis. To study how radiation affects neurogenesis, we combine phenotyping of subpopulations of hippocampal neural stem and progenitor cells with double- and triple S-phase labeling paradigms. Using this approach, we reveal new features of division, survival, and differentiation of neural stem and progenitor cells after exposure to gamma radiation.

Correlation-and-Spectral Analysis of Time Series for Microcirculatory Parameters in Vessels of Symmetrical Organs.

The correlation relationships between microcirculatory parameters were studied in vessels of symmetrical organs in humans. Parameters of microcirculation in healthy volunteers were measured by the method of laser Doppler flowmetry (LDF). LDF-signal transducers were placed symmetrically on the lower parts of the right and left shoulders (3 cm above the elbow bend).

Effect of Antibodies to Glutamate on Age-Related Memory Changes in C57Bl/6 Mice.

Chronic intranasal administration of antibodies to glutamate to aging C57Bl/6 mice improved passive avoidance conditioning, had no effect on horizontal and vertical locomotor activity, but slowed locomotion in the open-field test. Administration of antibodies to glutamate increased the content of dopamine and its metabolites in mouse hippocampus, but had no effect on the metabolism of neurotransmitter amino acids. In the frontal cortex, antibodies to glutamate did not affect neurotransmitter metabolism, but increased the level of both excitatory and inhibitory amino acids without changing their ratio.

Effects of early-life stress and HDAC inhibition on maternal behavior in mice.

Despite the well-established fact that maternal care plays a pivotal role in the offspring development, little is known about the effects of disruption of maternal care early in life on the development of this behavior in the offspring. Using brief repeated maternal separation (45 min/day on postnatal Days 3-6), which represents a model of early life stress, we found behavioral changes in adult female mice offspring. The decrease in home cage exploratory behavior (both pup-directed and nonpup-directed) was revealed later in adulthood without changes in maternal care level.

Prenatal Sensory Stimulation Induces BDNF Gene Expression in the Brain and Potentiates the Development of Species-Specific Predisposition in Newborn Chicks.

We studied the effects of light and non-specific sound stimulation of domestic chick embryos on their filial preference as well as on the expression of two transcriptional factors c-Fos and Egr-1 and neurotrophin BDNF in the embryo brain. Prenatal light stimulation increased preference of the "natural" object, thus producing a priming effect. In the brain of E19 embryos, c-Fos and Egr-1 were expressed at a high basal level and neither light nor sound stimulation affected the number of cells expressing these factors.

Recovery of Impaired Memory: Expression of c-Fos and Egr-1 Transcription Factors during Restoration of Damaged Engram in the Chick Brain.

Impairment of protein synthesis in the brain during learning prevents memory consolidation and results in amnesia, which until recently has been regarded irreversible. However, in some cases impaired memory could be restored by various "reminder" stimuli. The present study is based on the hypothesis that even in behaviorally profound amnesia, some disintegrated fragments of the engram are preserved in the brain and could be re-integrated into the whole system by specific types of stimuli.

Peculiarities of Participation of DNA Methyltransferases in the Mechanisms of Storage, Impairment, and Recovery of Conditioned Food Aversion Memory.

We studied the participation of DNA-methylation processes in the mechanisms of memory storage and reconsolidation, amnesia induction, and in recovery of the conditioned food aversion memory in edible snails. It was found that daily injections of DNA methyltransferases inhibitor over 3 days combined with a reminder of a conditioned food stimulus did not affect memory storage. The administration of DNA methyltransferase inhibitors did not suppress induction of amnesia caused the NMDA receptor antagonist/reminder.

Dynamics of Metabolic Parameters in Rats during Repeated Exposure to Modulated Low-Intensity UHF Radiation.

Metabolic parameters in rats were studied at various stages of repeated exposure to modulated low-intensity UHF radiation. The volume of O consumption and level of heat release were reduced by day 4 of intermittent irradiation and remained low over the next 2 days in the absence of a source for electromagnetic radiation. The amount of expired CO slightly increased over the first 3 sessions of irradiation, but significantly decreased in the recovery period on days 5 and 6.

Method for Studies of Orientation and Exploratory Behavior in Humans. Effects of Emotional Stress.

We developed a new experimental model for studies of orientation and exploratory behavior in humans. This method allows analysis of variants of orientation and exploratory behavior in humans, including risky behavior, and cognitive and individual typological parameters. The model allows distinguishing examinees with high and low orientation and exploratory activity, which helps to determine their psychoemotional status.

Influence of Caffeine Consumption by Pregnant Rats on Behavior and Learning in Their Offspring.

We studied the effect of long-term prenatal administration of caffeine on the behavior and learning of rats in postnatal ontogeny. Experiments were carried out on male rats born by females receiving caffeine solution as the only source of fluid throughout gestation. The control group consisted of pups obtained from females receiving drinking water throughout pregnancy.