Interhemispheric Differences in Indices of α Activity Spectral Power Electroencephalogram during Bicycle Ergometry

An EEG study during bicycle ergometry in the prone position with the load growing stepwise to submaximal heart rate was carried out in 30 volunteers in order to investigate the spectrum parameters and interhemispheric differences in α activity on the encephalogram. Comparative analysis of EEG data showed a statistically significant increase in α power indices in both hemispheres at the final stage of aerobic exercise and in the course of recovery period with the highest power values recorded in the left hemisphere. Analysis of interhemispheric differences demonstrated right-hemisphere activation during the entire period of the research.     

Effect of space flight factors on health of cosmonauts in the near and late term after space flights

Cytogenetical studies of cosmonauts' peripheral blood lymphocytes after space flights on MIR orbital station showed a statistically significant increase in the yields of radiation-induced chromosomal aberrations. However, similar studies with in vitro irradiation of biological objects with accelerated charged particles are of great importance for elucidation of the nature of cytogenetical damage induced in vivo. It is also important to investigate the structure of cosmonatus' diseases over their life, in particular, lens opacities and oncological diseases. Thus, the purpose of the investigations planned is to study cytogenetical damage in blood lymphocytes from cosmonauts after space flights on the ISS in vivo, as well as in donor blood lymphocytes after in vitro exposure to accelerated charged particles. The tasks of the project are as follows: determination of the yields and types of chromosomal aberrations in cosmonauts' blood lymphocytes before and after space flights, comparative studies of biological effects induced in vitro by different types of ionizing radiation in human blood lymphocytes in ground experiments, assessment of cytogenetical risks, analysis of the structure of cosmonatus' diseases comparing with that of whole population, study of the mortality and frequency of cataracts and oncological diseases in cosmonauts. The results to be obtained will be used for setting of health norms applied to the influence of radiations of different types, and for elaboration of measures to reduce health risks from space flight factors.     

Ophthalmic changes associated with long-term exposure to microgravity

The review discusses recent foreign publications on the problem of ophthalmic changes associated with long-term effects of microgravity during space flights. The states including hyperopic shift of refraction, a change in intraocular pressure, increased intracranial pressure, alterations in the choroid and retinal tissues, and optic disk swelling have been described. These effects are caused by redistribution of blood and fluid to the upper part of the body, increased intracranial pressure, and congestion of venous blood and lymph in the upper part of the body and head. Other factors that may trigger microgravity-induced vision impairment have also been considered. Photographic illustrations of changes have been provided.     

Complex action potentials of secondary neurons of the rat olfactory bulb

Complex action potentials arising spontaneously or evoked by stimulation of the lateral olfactory tract in secondary neurons of the rat olfactory bulb were recorded. The amplitude and duration of the complex potentials varied depending on synchronization of onset of the individual components (of which more than four were distinguished) and their combination. It is suggested that complex potentials were recorded in cases when the electrode was located in the region of the junction between spike-generating zones (the branching node of the dendrite, the junction of the soma with the dendrites and axon). It is concluded that there are numerous generating zones in the dendrites of the secondary olfactory neurons. Evoked action potentials appeared after the following latent periods: first, about 1 msec; second, about 2 msec; and third, about 3 msec. The results of the analysis showed that the antidromic response appeared after the shortest latent period. These results are evidence of the existence of considerable and varied representation of excitatory synapses in secondary neurons (besides the excitatory input in the olfactory glomeruli).M. B. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 8, No. 6, pp. 575–582, November–December, 1976.     

Polyunsaturated and Very‐Long‐Chain Fatty Acids Are Involved in the Adaptation of Maloideae (Rosaceae) to Combined Stress in the Mountains

One of the mechanisms of plant adaptation to combined stress under conditions of altitudinal zonation is changing the lipid fatty acid (FA) composition. The main changes in the FA composition occurred in the outer cell layers of the pericarp, but not in the parenchyma. Adaptation was found to be species‐specific. In Cydonia oblonga Mill . and Malus domestica Borkh ., the ratio of polyunsaturated 18:2 and 18:3 lipid FAs changed with increasing height, while a constitutive level of the unsaturation index (UI) and low contents of very‐long‐chain fatty acids (VLCFAs) were maintained. Mespilus germanica L. was characterized by a higher level of VLCFAs due to the high content of 20:0. The sum of VLCFAs in medlar increased by up to 16 % with changing altitude, which was accompanied by the changes in the ultrastructure of chloroplasts and a noticeable decrease in the UI. We attribute the differences in the adaptive strategies in C. oblonga, M. domestica and M. germanica to specific structural features of the pericarp peel. Despite different adaptation mechanisms, the studied species can grow equally successfully at the altitudes from 300 to 1200 m.     

Endothelial Dysfunction and Metabolic Effects of Nitric Oxide in Humans

Shortage of nitric oxide (NO) is believed to be a key factor in the development of endothelial dysfunction. Metabolic effects of NO were analyzed in subjects with multiple metabolic disorders (essential arterial hypertension, platelet hyperaggregability, and hypercholesterolemia). Effects of the NO-inducing ₁-adrenoblocker nebivolol on the blood rheology and lipid profile were studied in pilots regularly exposed to factors of flying work contributing to the development of endotheliocyte dysfunction. The dynamics of spontaneous platelet aggregation in pilots with arterial hypertension suggested that nebivolol produced a statistically significant general effect on platelets, reducing their baseline activation by eliminating endothelial dysfunction. This NO-inducing drug has an antiatherosclerotic effect. Metabolic effects of NO are essential for normalizing endothelial functions because this messenger interacts with key reactions of the pathogenic cascade in the cardiovascular continuum.     

Computer modeling of information processing mechanisms in the olfactory system. III. Reproduction of psychophysical phenomena by the olfactory bulb model

Psychophysical phenomena typical of olfaction were reproduced using a computer model of olfactory bulb. The procedure of numerical experiments is described. The model reproduces the following phenomena: fusion of odors, strong and weak odors, suppression of weak odors by strong odors, indemnity of odors, changes in odor with time, consecutive olfactory images, sensibilization, consecutive olfactory constrast, and synergims. It was concluded that computer-assisted experimentation in combination with neurophysiological and psychophysical experiments can considerably increase the efficiency of research of odorants and the olfaction process.