Changes in the level of oxygen tension in different brain structures of rats in positive and negative emotional states

Changes of oxygen tension (pO2) level in various brain structures were studied in rats in positive and negative emotional states. It is established that pO2 level changes depend on the character of behavioural reactions: "active" type of behaviour (emotionally positive orienting-investigatory, actively defensive) is accompanied by pO2 level increase, and "passive" type of behaviour ("freezing" reaction)--by a decrease of pO2 level. Changes of oxidative brain metabolism observed at "active" and "passive" types of behaviour indicate, respectively, adaptive and nonadaptive character of these behavioural reactions.     

Effect of glycosphingolipids on erythrocyte Na+,K+-ATPase activity

The total fractions of gangliosides and cerebrosides isolated from the tissue of human brain were studied for their effect on the Na+, K+-ATPase activity of native erythrocytes and their membranes. It is shown that gangliosides depending on time of their preincubation with the enzyme preparation and concentration produce both the activating and inhibiting action and cerebrosides--only the inhibiting one. Gangliosides inhibit the transport ATPase activity noncompetitively with respect to ATP and Na+ and competitively--to K+, cerebrosides inhibit it noncompetitively with respect to all ATPase activators.     

New radiolarian species from the Upper Cretaceous-Lower Paleogene of the eastern slope of the northern Ural Mountains

Five new radiolarian species, Dictyophimus? orbiculiporosus sp. nov., Spongomelissa imperceptusa sp. nov., Theocoronium puncticulatum sp. nov., Pterocyrtidium porrectum sp. nov., and Tripodiscinus corona sp. nov., from the Campanian-Danian diatomites of the Leplinskaya Formation of the northern Ural Mountains are described. They are useful for stratification and correlation of the Upper Cretaceous and Lower Paleogene beds of the Ural Region of Western Siberia.     

Ethosuximide Improves Cognitive Flexibility during Reversal Learning in WAG/Rij Rats with Absence Epilepsy and Comorbid Depression

Journal of Evolutionary Biochemistry and Physiology - The WAG/Rij rat strain is a valid model of absence epilepsy with comorbid depression. Absence epilepsy, along with symptoms of depression, is...     

Possible mechanisms of unilateral hippocampal insult after bilateral occlusion of common carotid arteries in rats with different types of behavior

Possible mechanisms of unilateral ischemic insults in CA1 region of hippocampus and anterior dorsal nuclei of thalamus after bilateral occlusion of common carotid arteries in rats with different types of behavior are discussed.     

Genetic markers and psoriasis in three ethnic populations of Dagestan

Analysis of clinical material obtained from the individuals (49 psoriasis patients and 357 individuals without this disease) representing three ethnic populations of Dagestan (Avars, Dargins, and Kumyks) was performed. Polymorphism of the blood group loci AB0, Rhesus (RH), Kell, P, and Lewis, as well as of the protein-encoding loci for haptoglobin (HP), group-specific component (GC), and the enzymes, including glycosylase (GL01), esterase D (ESD), 6-phosphate dehydrogenase (6PDG), and acid phosphatase (ACP), was studied. It was demonstrated that in the pooled sample of Avars and Kumyks the Lewis system phenotype Le(a-b-) and the RH homozygotes (ee/ee) were statistically significantly more frequent among the psoriasis patients (P = 0.0488 and P = 0.0166, respectively), than among healthy controls of the same ethnic groups. It was suggested that for the pooled sample of Avars and Kumyks, homozygosity for the recessive RH allele (ee/ee) in combination with the Le(a-b-) phenotype, representing homozygosity for recessive allele le, was the risk factor for the development of psoriasis.     

Effects of heptapeptide selank on genetically-based and situation-provoked symptoms of depression in behavior in WAG/Rij and Wistar rats, and in BALB/c mice

A synthetic derivative of the endogenous peptide tuftsin heptapeptide selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) possesses an anxiolytic and psychostimulant effect, and represents a working element of a new peptide drug having completed the third phase of the clinical testing as a selective anxiolytic. The neurobiochemical spectrum of selank action combines mechanisms which are characteristics of antidepressants and psychostimulants: activation of the brain monoaminergic systems, dopamine synthesis and turnover, and modulation of the tyrosine hydroxylase activity. The aim of this study was to investigate the effect of selank in a new model of inherited (genetically-based) symptoms of depression in behavior of inbred WAG/Rij rats in comparison with its effect on situation-provoked symptoms of depression in behavior of BALB/c mice. Outbred Wistar rats constituted control group. Selank in high doses (1000-2000 microg/kg), after repeated injection counteracted symptoms of depression in behavior of WAG/Rij rats (increased immobilization in the forced swimming test and decreased sucrose intake or preference (anhedonia)). Selank in low doses (100 and 300 microg/kg) after single injection reduced the duration of immobility of BALB/c mice in the forced swimming test, but did not exert significant effect after repeated injection or after injection in high doses (600 and 900 microg/kg). Selank did not affect the level of general locomotor activity and anxiety in WAG/Rij rats, and did not exert substantial effect on the behavior of control Wistar rats. The results demonstrate the presence of antidepressant component in the spectrum of neuropsychotrophyc activity of selank and indicate the higher reliability of a new experimental model of depression (the WAG/Rij rats) as compared to the standard forced swimming test for the determination of antidepressant activity of a pharmacological drug.     

Contractile capacity of isolated flaps from the aorta of rats with stable arterial hypertension caused by the prolonged administration of cerebrosides

A study was made of the contractility of smooth muscle cells of abdominal aorta strips of noninbred white rats with stable arterial hypertension induced by protracted intraperitoneal injection of cerebrosides isolated from cattle brain. It was demonstrated that as compared with normotensive animals, smooth muscle cells of the animals' arteries are characterized by the increased influx of extracellular calcium via slow potential-dependent calcium channels and hypersensitivity to noradrenaline and serotonin.