ABSTRACT
In relation to Cosmos experiments behavioural responses of rhesus monkeys were investigated and compared with their conditioned reflex activities. The animals with a distinct search-oriented behaviour showed a higher rate of recovery of instrumented reflexes, better stability of conditioned-reflex activities to stress-effects and a faster adaptation to them. Extreme effects associated with changes in the experimental environment and rigid fixation inhibited conditioned-reflex activities to a greater extent than strong but short-term exposures followed by tests in a normal environment. It was also demonstrated that variations of the sleep structure in stress situations were largely dependent on typological features of animals.
Subject(s)
Behavior, Animal/physiology , Conditioning, Classical/physiology , Escape Reaction/physiology , Exploratory Behavior/physiology , Models, Psychological , Stress, Psychological/psychology , Adaptation, Physiological/physiology , Adaptation, Psychological/physiology , Animals , Macaca mulatta , Male , Restraint, Physical , Sleep/physiology , Stress, Psychological/physiopathologyABSTRACT
The data on the sleep structure of two rhesus monkeys, Vernyi and Gordyi, during their 7-day space flight on Cosmos-1667 and a control study staged a month after recovery are discussed. Sleep structure was changed to the greatest extent the night before launch when additional stress factors were involved. During the first night in space Vernyi showed the so-called recoil effect. Later his sleep structure became stabilized: the specific weight of fast sleep diminished and the fast sleep/delta/sleep index in the first two cycles decreased. In the ground-based control study, sleep parameters pointed to a deteriorated health status of the animal: his fast sleep patterns changed and delta-sleep often reached its maximum after a fast sleep episode. In this animal adaptation was associated with fast sleep restructuring. In the second primate, Gordyi, the process of adaptation was extended and took three nights. This animal consistently showed low parameters of delta-sleep during both fright and postflight control study; it exhibited no recoil phenomenon after its reduction in the prelaunch night. The structure of sleep indicated that it played a lesser role in the overall process of adaptation.
Subject(s)
Aerospace Medicine , Models, Biological , Sleep/physiology , Space Flight , Adaptation, Physiological/physiology , Animals , Circadian Rhythm , Extraterrestrial Environment , Geological Phenomena , Geology , Macaca mulatta , USSRABSTRACT
The effect of 21-day exposure to +2 Gx and +1.1 Gx on the contractile properties of different muscle groups of rat fore- and hindlimbs was examined, using glycerinated myofibers in the ATP + Ca2+ solution. It was found that the isometric contraction strength and velocity increased, the performance of the postural extensors also grew: that of the soleus m. in the +2 Gx rats and that of the triceps brachii m. in the +2 Gx and +1.1 Gx rats. The contractile changes of the flexors of fore- and hindlimbs were insignificant and sometimes oppositely directed. The different responses of the muscles to acceleration were associated with the differences in their function, metabolism and biomechanics.
Subject(s)
Acceleration , Gravitation , Isometric Contraction , Muscle Contraction , Adaptation, Physiological , Animals , Forelimb , Hindlimb , Rats , Stress, Mechanical , Time FactorsABSTRACT
Development of isometric tension in the preparations of glycerinated fibrils of different skeletal muscles in ATP + Ca2+ solution, as well as composition of muscle contractile and regulatory proteins were studied on white rats exposed on biosatellite "Kosmos-1129" for 18.5 days. Expression and trends of the changes in contractile properties of muscle preparations depend on their structural-functional specialization and biomechanical peculiarities. In each case adequate rearrangement of the composition of light myosin chains takes place. Changes in subunit composition of troponin-tropomyosin complex were recorded. High activity of catalase in muscle proteins disproportionate to the loss of their mass in single muscles was observed. The results obtained are in favour of possible adequate transformation of fibril phenotypes of some (antigravitational) muscles under the effect of space flight.
Subject(s)
Muscle Proteins/physiology , Muscles/physiology , Myofibrils/physiology , Space Flight , Animals , Muscle Contraction , Rats , Rats, Inbred StrainsABSTRACT
Contractile properties of glycerinated fibers of skeletal muscles of rats flown for 18.5 days on Cosmos-936 were investigated. In slow antigravitational muscles (soleus m. and triceps brachii m.), decrease in the amplitude of isometric tension and performance as well as acceleration of the contraction development were observed. The studies point to a high specificity of reactions of skeletal muscles to the experimental conditions, depending on their functional specialization. It is suggested that changes in contractile properties of myofibrillar proteins may contribute to the adaptive rearrangement of functional properties of antigravitational muscles under the influence of space flight.
