Cytogenetic analysis of the effect of cosmic flight factors on man]

The results of cytogenetic investigation of 14 crewmembers of "Soyuz" spacecrafts before and after 7 spaceflights are represented. No cytogenetic changes were noted at the investigated crewmembers on the first postflight day as compared to the preflight data. Possible causes of differences between the author's data and the data of foreign investigators on cytogenetic investigation of American crewmembers are discussed in the article.     

A new method of assessing anxiety-phobic states in rats]

A new multiparameter method for evaluating anxiety-phobic states in rats is elaborated. The method is based on the ranged scale consisting of parameters which characterize the species-specific rat response to the series of ethologically adequate test-stimuli inducing manifestation of the anxiety-phobic states. The method makes it possible to evaluate individual anxiety-phobic level in rats, to form experimental groups with rats of known individual anxiety-phobic level, to conduct repeated observations in the same animals. The method is easy to perform in laboratory and makes it possible to get the results quickly.     

The mechanism of the resistance of methicillin-resistant Staphylococcus aureus to phages from the International Collection

The resistance of methicillin-resistant staphylococci to phage 85 is due to the presence of a certain system restriction modification in microbial cells. The loss of the capacity for restricting phage DNA by the cell as the consequence of the loss of the mec determinant is not accompanied by the loss of its capacity for modifying phage DNA.     

Alterations in diurnal sleep structure, electrical activity, and neurochemical parameters of the rat brain induced by systemic injection of complete Freund adjuvant and immunization by bovine serum albumin with complete Freund adjuvant

Investigations of the effects of animal immunization with immunogenesis stimulator Freund's adjuvant complete (alone or in combination with bovine serum albumin often used in control experiments) on brain electrical activity, sleep, and neurochemical parameters were carried out in male Wistar rats. It was shown that both injection of Freund's adjuvant complete alone (0.25 ml) and immunization with bovine serum albumin (2 mg/kg in 0.25 ml of saline) mixed with Freund's adjuvant complete (0.25 ml) led to an increase in the slow-wave and REM sleep. After injection of Freund's adjuvant alone, development of sleepiness was gradual and reached its maximum within 3-5 weeks, while after the combined treatment the alterations in the sleep structure became pronounced already 1 week after the first antigen injection and persisted at least for 5 weeks. Neurochemical analysis revealed no significant changes in the noradrenaline, dopamine, and serotonin content in striatum and frontal neocortex after the injection of Freund's adjuvant. After the combined treatment, the serotonin content in these structures decreased. After the Freund's adjuvant injection, the dynamics of changes in power spectra of the brain electrical activity of different brain structure in the state of quiet wakefulness was complicated. Increase in the slow-wave activity in the delta 1 range (1-2 Hz) in caudate putamen, basomedial nucleus of amygdala, and sensorimotor cortex was observed in the animals immunized with bovine serum albumin mixed with Freund's adjuvant complete 1 week after the antigen injection and later on during the whole observation period. This was probably associated with an adaptive increase in the functional activity of serotoninergic system.     

Immunization of rats with bovine serum albumin conjugate with dopamine or 5-hydroxytryptamine prevents the development of experimental MPTP-induced depressive syndrome. An electrophysiological study

In electrophysiological experiments in Wistar rats it was shown that preventive immunization of animals with bovine serum albumin conjugated with dopamine or 5-hydroxytryptamine or with bovine serum albumin alone partly protects against the development of experimental MPTP-induced depressive syndrome. Signs of depressive-like state such as decrease in REM-sleep latency and the development of epileptiform activity in caudate putamen were not observed in immunized animals, whereas REM-sleep proportion in the total sleep structure was increased. Changes in the spectral characteristics of brain electric activity and sleep structure during development of experimental MPTP-induced syndrome in immunized rats are antigen-specific and reflect the functional shifts in neurotransmitter systems, both in those which are the target of the immune action and those sensitive to alterations in the immune state of a body.     

The effect of active immunization with a conjugate of dopamine and bovine serum albumin on the development of an experimental MPTP-induced depressive syndrome and on the monoamine metabolism in the brain of rats

Active immunization with dopamine conjugated with bovine serum albumin (DA-BSA) or BSA with complete Freund's adjuvant (CFA) partly suppressed the development of the MPTP-induced depressive syndrome in rats preventing the appearance of "behavioral despair" symptoms: increase in immobility time and higher index of depression in forced-swim test. In DA-BSA-immunized rats the content of DOPA, DA, HVA, NA, and 5-HN in caudate putamen and that of NA in the frontal cortex was increased, while in BSA-immunized rats the content of 5-HT in both brain areas and that of DOPAC in the frontal cortex was decreased both in rats with reduced depressive syndrome and in saline control as compared with intact animals a day after the last drug injection. In DA-BSA-immunized rats with reduced depressive syndrome the increase in DA and 5-HT content in caudate putamen was less expressed and DOPAC content was lower than in saline control. In BSA-immunized depressive rats DA content in the frontal cortex was also reduced as compared to control.     

The search of small molecules with antipsychotic activity on the background of neurotensin

Tridecapeptide neurotensin (NT) is known to exert the neuroleptic-like effects in case of its intracerebral administration. The group of systemically active dipeptides , acylprolyltyrosines, was constructed on the background of NT. Methyl ester of N-caproyl-L-prolyl-L-tyrosine (Dilept) was chosen for further development. The paper is dealing with main principles of Dilept'design and with analysis of the experimental data concerning its effect on the "translational" model of schizophrenia--the deficit of prepulse inhibition of the acoustic startle-reaction caused by either dopamine-mimetic, apomorphine, or by the uncompetitive NMDA-blocker, ketamine. Dilept was shown to attenuate these deficits both in case ofintraperitoneal and peroral administration. Dilept is considered as a potential antipsychotic.     

Behavioral consequences of isolation in early ontogeny in rats: selectivity of anxiety conditions

Multiparameter scale for evaluation of anxiety-phobic state in rats reveals significant enhancement of anxiety in rat pups after 6-week isolation (beginning from the 21st day from birth) as compared to grouped controls of the same litter: the locomotion and exploration that appear in test areas are suppressed, and species-specific fear reactions are enhanced. These changes considered as signs of situational anxiety are not eliminated by 2.5-month keeping in groups. Nevertheless, they are not correlated with parameters of the acoustic startle reflex that (by the data of literature) is thought to be related with fear and anxiety. On the basis of the discrepancy it is proposed that state of anxiety is selective. This suggestion is confirmed by individual behavioral variations characterized by a combination of a low level of situational anxiety and a high level of acoustic anxiety observed in both experimental and control groups. These variations may explain the existence of atypical "emotional resonance"-like behavior according to P.V. Simonov. Attention is given to selectively enhanced acoustic startle reflex in the group of active control as an evidence for critical importance of any manipulations with social context in early ontogeny.