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Biomedical subjects

Z I Apanasenko

Publications and source records attributed to Z I Apanasenko.

At least 19 recordsLinked to original sources
PubMed1981

[Effect of artificial gravitation during space flight on motor habit retention in white rats].

The recovery of a goal-reaching habit (food reaching) was studied in albino rats in a maze after space exposure on biosatellite "Kosmos-936". Animals which were exposed to artificial gravitation during the flight, restored the habit slightly worse than those not centrifuged. The tendency toward worsening is clearly pronounced, although the small number of animals and small changes (which to a considerable degree was due to relatively simple tasks) seem to produce insignificant differences at this stage of the study. The absence of positive effect of artificial gravitation might be connected with a negative effect of angular speeds during centrifugation.

Animals↗
PubMedDate not supplied

[The reproductive function of male rats following space flight on the Cosmos-1667 biosatellite].

After the 7-day space flight of Cosmos-1667 the reproductive system of white rats was investigated. No differences between the flight rats and synchronous and vivarium controls were detected with respect to such parameters as the testis and epididymis weight, testicular content of spermatogonia, spermatocytes, spermatids, spermatozoa, Leydig's cells and Sertoli's cells, and the number of normal and atypical spermatozoa in the epididymis. Nuclei of Sertoli's cells were similar in size in the flight and control rats. Electron microscopy of the first order spermatocytes showed no increase in the frequency of chromosome aberrations. Postflight, the flown males were mated with control females; their sex activity and their offspring were normal; the pups did not differ from the norm with respect to the litter size, proportion of males and females in the litter, growth rate in the postnatal period, physical development or function of the nervous system. These observations allow the conclusion that short-term space flight produces no effect on the reproductive system of white rats.

Animals↗
PubMedDate not supplied

[Behavioral reactions of animals subjected in the prenatal development period to space flight conditions].

The Wistar female rats were flown on the biosatellite Cosmos-1514 during their pregnancy days 13-18. Offspring (at the age 1 to 3 months) of four of these rats were used to investigate their behavioral reactions in the open field and mazes of different design, food attraction being applied. Control rats of matched pregnancy term were kept either in a vivarium or in a biosatellite mockup where all flight factors, except for weightlessness, were simulated. It was found that exposure to weightlessness in the above intrauterine developmental period caused no serious changes in the behavioral reactions of rats during their postnatal development. The number of refusals and errors and the latency period were similar in the rats from the flight and control groups. Changes were seen only in fine behavioral regulation. The flown animals displayed a lower research activity in the open field, a longer time of search in the maze, a far longer time or grooming and a greater number of inadequate movements, and a stronger response to external inhibiting stimuli. These changes seem to be caused by a slight attenuation of the basic nervous processes (primarily, inhibitory) and a decrease of their balance and lability. These effects may be associated with an inhibitory influence of space flight factors on the maturation of cortical structures.

Animals↗
PubMedDate not supplied

[General characteristics of an experiment to study the ontogeny of rats on board the Kosmos-1514 biosatellite].

Ten female Wistar rats were exposed to zero-g during 5 days, i. e., from gestation day 13 to day 18. After recovery the flight animals showed a significant delay in weight gain, thymus involution, decreased liver weight, hemoglobin concentration. Nevertheless, their reproductive function did not differ from that of the controls: the rate of preimplantation and total fetal mortality as well as the number of live fetuses were very similar in the experimental and control animals. The flight group showed a slight decline of fetal weight and water content. The size of the litters produced by the flight and control rats was identical but the mortality rate of those former during the first 7 days after birth was significantly higher. This experiment has demonstrated that the mammalian fetus exposed to zero-g during the last term of pregnancy, i. e., at the stage of active organogenesis, can grow and develop in the normal way. A large body of biological material has been obtained for biochemical and histological examinations that will help evaluate the condition of dams, fetuses, and newborns.

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PubMedDate not supplied

[Higher nervous activity of rats at early periods after the end of flight in the biosatellite "Cosmos-605"].

Functional changes of higher nervous activity were found in the rats after a 22-day flight in the biosatellite "Cosmos-605". The ability to retain and restore the habit of searching food in the maze deteriorated. The number of refusals to go through the maze increased with an enhancement of the functional load on the central nervous system. This resulted not only from reduced alimentary excitability or muscular weakness developed during the flight, but also from a weakening of the basic nervous processes in the higher parts of the central nervous system.

Animals↗
PubMedDate not supplied

[Behavior of rats in the labyrinth after a flight on the Cosmos-690 biosatellite].

Rats irradiated aboard the biosatellite Cosmos-690 and in the synchronous mockup showed deteriorated retention and recovery of the skill of traversing the maze. The rats irradiated on the Earth displayed greater changes in the parameters. The rats irradiated inflight exhibited an increased fatigue during enhanced activity. All the exposed animals showed an insignificant change in the capacity to transfer their experience.

Animals↗
PubMedDate not supplied

[Conditioned reflex activity of rats at later periods after the end of flight aboard the bioasatellite "Cosmos-605"].

During the period from the 15th to the 50th day after the end of the flight in the "Cosmos-605" biosatellite, the rats revealed a deterioration of the capacity for the transfer of experience and for improving the habit of reaching the goal in a maze. There was also a change in the dynamics of errors during the experiment which testifies to greater susceptibility to exhaustion of nervous processes. Some parameters indicated a tendency to normalization of higher nervous activity. This suggests that the disturbances observed are functional and reversible.

Adaptation, Physiological↗
PubMedDate not supplied

[Status of processes of internal inhibition in the rat during a flight aboard the biosatellite "Cosmos-1129"].

Changes of conditioned reflexes were analyzed in albino rats during their 18.5 days on board the "Cosmos-1129" bio-satellite. With total lowering of the level of conditioned activity, the most affected proved to be reactions linked with internal inhibition; differentions were disinhibited, the number of intersignal reactions significantly exceeded control values. During the experiment photoperiodic desynchronosis took place, the nature of which also testified to high sensitivity of the inhibitory processes to the action of cosmic flight factors.

Animals↗
PubMedDate not supplied

[Reproductive function of the male rat after a flight on the Kosmos-1129 biosatellite].

Male rats that were flown for 18.5 days on Cosmos-1129 were mated postflight with intact females. The mating 5 days postflight when the ejaculate consisted of spermatozoids that were exposed to zero-g effects in the mature stage yielded the litter which lagged behind the controls with respect to the growth and development during the first postnatal month. The mating 2.5-3 months postflight when the ejaculate consisted of spermatozoids that were exposed to zero-g effects at the stem cell stage yielded the litter which did not differ from the control.

Animals↗
PubMedDate not supplied

[Retention and recovery of a goal-achieving habit in rats after a flight on biosatellite "Cosmos-782"].

The retention and recovery of food-procuring skill in the maze was impaired in rats after 19.5-days space flight. The study conducted 2--12 days after landing, revealed an increase in the number of erroneous movements and of refusals to cope with the maze, as well as in the time of reaching the goal. These phenomena cannot be explained only by reduction of alimentary excitability and muscular weakness. It is assumed that the observed changes in the higher nervous activity were due to a weakening of the basic nervous processes which might be caused by a decrease in the sensory impulse activity during weightlessness.

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