Individual typological features in the EEG of athletes after acute hypoxic treatment

In athletes with different types of physical training and various temperaments, variability of the main rhythms of the EEG (??, ??, and ??) and the parameters of the desynchronization response of the ??-rhythm, the individual extent of the decrease in the power of the ??-rhythm during eye opening under the conditions of hypoxia growing from 20.9 to 10% of O₂ were studied. Twenty-four 18- to 26-year-old athletes, including 11 swimmers and 13 skiers, were involved in the study. We found that, in contrast to normoxia conditions, hypoxia was associated with the instability of the spectrum of the EEG rhythms and phasic changes during a 25-min hypoxia. The EEG response during hypoxia depended on individual typological features estimated using Strelau??s temperament questionnaire. Negative correlation between the psychological construct ??endurance?? measured using the FCB-TI questionnaire (Formal Characteristics of Behavior-Temperament Inventory) and the power of the EEG ??-rhythm was found. The parameters of training and the features of the respiration pattern that appeared as a consequence of training modulated the sensitivity of brain structures to hypoxia, which was reflected in the changes in the EEG ??-rhythm under hypoxia conditions.     

Individual factors in nasal chemesthesis

Population variability in nasal irritant (chemesthesic) sensitivity has been postulated by both clinicians and epidemiologists studying indoor and ambient air pollution. Among experimentalists, however, limited attention has been paid to variance in this trait. Candidate susceptibility markers include age, gender, presence or absence of nasal allergies or olfactory dysfunction, cognitive bias and self-reported pollutant reactivity. For most of these markers, conflicting data exist. This review distinguishes between functional subcomponents of nasal irritant sensitivity (sensory acuity versus physiologic reactivity), catalogs psychophysical and physiological methods for their study and examines the current evidence for variation in this trait. In general, interindividual variability has been an under-studied phenomenon.     

States of productive and reproductive imagination reflected in the local synchronization of alpha and theta EEG frequencies

Healthy subjects (n = 83) performed a task involving reproductive imagination (remembrances): they were asked to remember and to have an imaginary walk along a well-known road (a real walk, the reproductive imagination state, RIS). Then the subjects performed a task involving productive imagination: they were asked to imagine a city that does not actually exist and to have an imaginary walk through it (a fictitious walk, productive imagination state, PIS). The reference values were measured at rest with the eyes open (REO). Monopolar EEGs were recorded from 19 areas of the scalp surface (10–20 system). An increase in EEG power in the α₂ frequency range during RIS and even more pronounced increase during PIS as compared with REO were considered to reflect the internalization of attention. We also observed multidirectional dynamics of EEG power in the θ and α1 ranges during PIS and RIS as compared with REO, which suggests the dominance of free associative manipulation of visual images in PIS in contrast to RIS, where algorithmically ordered operations with visual images stored in the memory were dominant.     

Individual bacteria in structured environments rely on phenotypic resistance to phage

Bacteriophages represent an avenue to overcome the current antibiotic resistance crisis, but evolution of genetic resistance to phages remains a concern. In vitro, bacteria evolve genetic resistance, preventing phage adsorption or degrading phage DNA. In natural environments, evolved resistance is lower possibly because the spatial heterogeneity within biofilms, microcolonies, or wall populations favours phenotypic survival to lytic phages. However, it is also possible that the persistence of genetically sensitive bacteria is due to less efficient phage amplification in natural environments, the existence of refuges where bacteria can hide, and a reduced spread of resistant genotypes. Here, we monitor the interactions between individual planktonic bacteria in isolation in ephemeral refuges and bacteriophage by tracking the survival of individual cells. We find that in these transient spatial refuges, phenotypic resistance due to reduced expression of the phage receptor is a key determinant of bacterial survival. This survival strategy is in contrast with the emergence of genetic resistance in the absence of ephemeral refuges in well-mixed environments. Predictions generated via a mathematical modelling framework to track bacterial response to phages reveal that the presence of spatial refuges leads to fundamentally different population dynamics that should be considered in order to predict and manipulate the evolutionary and ecological dynamics of bacteria–phage interactions in naturally structured environments.

Bacteriophages represent a promising avenue to overcome the current antibiotic resistance crisis, but evolution of phage resistance remains a concern. This study shows that in the presence of spatial refuges, genetic resistance to phage is less of a problem than commonly assumed, but the persistence of genetically susceptible bacteria suggests that eradicating bacterial pathogens from structured environments may require combined phage-antibiotic therapies.     

Individual dynamics of the EEG running wave under various conditions of activity

In 25 healthy subjects at resting with their eyes closed and open, a current phase structure of the EEG was measured, i.e. a trajectory and velocity of oscillation spreading over the head surface in temporal-occipital area. Visual computer multiplication revealed stable individual specifics of the EEG "running wave" dynamics which were then confirmed independently proceeding from the statistical significance criteria. Some subjects had characteristic transversal modulations of the EEG waves (from the left fo the right and vice versa), other subjects manifested longitudinal modulations along the diagonal from the cortex left anterior areas to the right posterior those (in some of them) or along the same diagonal in the opposite direction (in others). When opening the eyes, the character of the EEG "running wave" undergoes dramatic changes. Among other parameters, a growth of the trajectory share occurs in occipital area along with acceleration of the "running wave" spreading on all other trajectories. Both effects are bound to each other and the sharper dynamics is specific for subjects characterised as sympathotonic those as compared with para-sympathotonic.     

Psychosomatic factors of resistance to hypoxia

During formation of human long-term adaptation to cold-hypoxic influence, the some dynamics of psychological mechanisms contribution was revealed. On the first step of adaptation process, emotional-volitional personal peculiarities are significantly contributing; on further steps, communicability and general learning abilities are gaining importance. Anxiety, tenseness, diffidence and too strong self-control limit the hypoxic resistance far before restriction of physiological markers of the organism's functional abilities. Adaptation to cold-hypoxic effect contributing to organism stress-limiting system is believed to help experiencing extreme somatic and psychic loads by the people from psychological risk group.     

Individual typological features reflected in different stages of learning and related changes in dopamine transport in the mesolimbic brain

A hypothesis is proposed according to which there is a strong similarity between the individual typological features of animals (humans) and different stages of learning processes. The hypothesis is supported by the results of comparisons of psychophysiological and neurochemical indices of different stages of conditioning and various typologies of higher nervous activity. Such comparisons reveal a high similarity between the generalization phase and impulsivity, the phase a learned conditioned reflex and self-controlled behaviour, and overlearned CR and a state of "psychosis". Functional states close to pathology and possibilities of development and manifestation of several psychotic states depending on psychophysiological and neurochemical organization of learning processes are also considered.     

Individual variation in somatic mutations of the glycophorin-A gene in neonates in relation to pre-natal factors

The frequency of somatic mutations of the glycophorin-A (GPA) gene was measured in red blood cells from a series of newborn babies and related to various epidemiological and lifestyle factors in order to identify those factors that might influence the mutation rate before birth. Although there was substantial variation in the mutation frequencies between individual babies, no specific associations were found with any of the factors explored including smoking, age and social class of the parents, and gender and birth weight of the babies. It is concluded that these factors do not have a substantial effect on the mutational endpoint measured, although this does not necessarily mean that they have no effect on health risk to the offspring. The observed variation in GPA gene mutation frequency must, therefore, be due either to exposure to less obvious external influences or to intrinsic factors.     

Host factors involved in resistance to retroviral infection

Viral replication requires the help of host cell factors, whose species specificity may affect viral tropism. On the other hand, there exist host factors that restrict viral replication. The anti-viral system mediated by some of these restriction factors, which is termed intrinsic immunity and is distinguished from conventional innate and adaptive immunity, has been described as playing an important role in making species-specific barriers against viral infection. Here, we describe the current progress in understanding of such restriction factors against retroviral replication, focusing on TRIM5alpha and APOBEC, whose anti-retroviral effects have recently been recognized. Additionally, we mention cyclophilin A, which is essential for HIV-1 replication in human cells and may affect viral tropism. Understanding of these host factors would contribute to identification of the determinants for viral tropism.     

Proteomics to identify resistance factors in corn-a review

The host resistance strategy for eliminating aflatoxins from corn has been advanced by the discovery of natural resistance traits such as proteins. This progress was aided by the development of a rapid laboratory-based kernel screening assay (KSA) used to separate resistant from susceptible seed, and for investigating kernel resistance.A. flavus GUS transformants have also been used, in conjunction with the KSA, to assess the amount of fungal growth in kernels and compare it with aflatoxin accumulation. Several proteins associated with resistance (RAPs) have been identified using 1 D PAGE. However, proteomics is now being used to further the discovery of RAPs. This methodology has led to the identification of stress-related RAPs as well as other antifungals. Characterization studies being conducted, including RNAi gene silencing experiments, may confirm roles for RAPs in host resistance.     

Individual/Typological Peculiarities of EEG Rearrangements in Humans Related to the Analysis of Olfactory Information: Role of Extroversion/Introversion

We studied changes in human EEGs related to presentation of olfactory stimuli (smells of essential oils) and dependence of such rearrangements on the level of extroversion/introversion typical of the tested subject. It was shown that this feature of personality noticeably influences the pattern of odorant-induced changes in EEG. Persons with a predominance of introversion were characterized by higher levels of nonspecific activation of the brain related to perception of olfactory stimuli, which was manifested in a decrease in the power of low-frequency EEG components in the parietal, occipital, and temporal cerebral cortices. The pattern of the rise in coherence level of high-frequency spectrum range oscillations directed toward caudal leads is considered a manifestation of intensification of the intrinsic associative processes. In individuals with a predominance of extroversion, we observed, on the whole, smaller levels of nonspecific cerebral activation upon the action of olfactory stimulation. The fronto-parietal pattern of spatial EEG synchronization is indicative of the development of sensory-analytical processes related to perception of external information. In general, our data agree with the interpretation of such a psychological parameter as extroversion/introversion.     

Dynamic values of the EEG factors in the human perception of sound stimuli

In 43 healthy subjects passing from the state of calm alertness to various conditions of perception of short sounds of different height, interchanging at random, the most expressed is a generalized reduction of individual values of the EEG factor I positively related to the index, mean amplitude and regularity of the alpha-activity and also to mean beta- and theta-amplitudes and negatively related to the theta-index. Maximum reaction by this factor is observed at the beginning of the stimulation; at the second minute of the stimulation, the factor values return towards the initial background level, and again, to a lesser degree, are reduced when carrying out tasks on the sound analysis of stimuli, and the more difficult is the task the stronger is the reduction. In all cases the parietal regions are more reactive than the central ones. By the EEG factor II positively related to the index, frequency and regularity of the beta-activity, the reaction is less expressed and is more local: the factor values in the parietal areas augment only at the beginning of stimulation and diminish at the second minute; and in the central parts, on the contrary, there is a tendency to increase only at the second minute of stimulation. At the sound analysis, reaction is poorly expressed by this factor. Changes of values of the EEG-factor III, positively related to the mean period of the alpha-waves and theta-index, are not great and have only a general tendency to increase at the beginning of the stimulation, and to lower to the background level at the second minute.