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We report here a study examining the effects of acute normobaric hypoxia in the early postnatal period of development (postnatal day 2) on learning ability and the expression of GABAB receptors in the neocortex (medial prefrontal cortex) of adolescent rats (postnatal days 55–60) and also addressing the possibility of correcting identified disorders with the Russian-made drug salifen, a GABA derivative. Perinatal hypoxia has been shown to impair the formation and retention of memory traces in the novel object recognition and conditioned passive avoidance reflex tests and to reduce spatial learning ability in the Morris water maze test. Analysis of Western blot results revealed an increase in the quantity of GABAB receptor protein in the medial prefrontal area of the neocortex of rats exposed to perinatal hypoxia. Administration of salifen 15 mg/kg for 14 days after exposure to hypoxia improved the cognitive abilities of rats and normalized the level of GABAB receptor protein expression in the medial prefrontal cortex of rats. The results obtained here are of interest for solving an applied challenge in neonatology – the search for effective pharmacological correction of the sequelae of perinatal hypoxia. [ABSTRACT FROM AUTHOR]

Abstract—We studied the effect of prenatal stress on the activity of glutathione-bound enzymes in the subcellular fractions of neurons and neuroglia of rat neocortex. The results of the study showed that prenatal stress causes changes in the activity of these enzymes in both neurons and neocortical neuroglia. These changes differ in the subcellular fractions of the studied cell populations. In the nuclei of neurons and neuroglia fraction, the activity of glutathione peroxidase increases. In the cytosol of neurons fraction, the activity of glutathione peroxidase decreases, while in the cytosol of neuroglia it grows. In neuronal mitochondria, the activity of glutathione peroxidase and glutathione transferase increases, while in the neuroglial mitochondria fraction, the activity of glutathione peroxidase decreases. It has been suggested that a change in the activity of these enzymes in the subcellular fractions of neurons and neuroglia is one of the causes for the resistance of the neocortex to the effects of prenatal stress. [ABSTRACT FROM AUTHOR]

To study the role of somatotropin (ST) in osmotic regulation of anadromous acipenserids, the dynamics of hormone concentration in blood serum of juvenile Russian sturgeon Acipenser gueldenstaedtii Brandt (age 4 months, average length 16.9 cm, average weight 17.1 g) during fish adaptation to hyperosmotic medium of 12.5‰ salinity (403 mOsm/l) was evaluated for the first time. During the first 24 h after the transfer of fish from freshwater to hyperosmotic medium, an increase of ST serum concentration (up to 2.06 ± 0.09 vs. 0.98 ± 0.03 pg/ml in control fish from freshwater) was observed. This increase occurs concurrently with an increase in blood serum osmolarity (up to 386.2 ± 4.0 mOsm/l vs. 218.5 ± 4.9 mOsm/l in control) resulting from the diffusion of water from the organism under new osmotic gradient, as well as with the period of morphofunctional remodelling of the osmoregulatory system corresponding to the transition of fish to hypoosmotic regulation. 24 h after the start of the experiment, fish that have shifted to hypoosmotic regulation display the adaptive decrease in osmolarity (aimed at maintaining the relative constancy of blood serum) and the ST concentration (down to 1.18 ± 0.16 pg/ml after 120 h, comparable with that in the control fish). It is concluded that during transition of juvenile Russian sturgeon to hypoosmotic regulation, ST becomes involved in morphofunctional remodelling of the osmoregulatory system concurrently with other components of this system. ST-immunopositive cells were revealed in the dorsal part of mesoadenohypophysis of Russian sturgeon juveniles by immunochemical method. [ABSTRACT FROM AUTHOR]

The effect of stress in pregnant female Wistar rats on the behavior and lipid peroxidation (LP) in the neocortex, hippocampus and hypothalamus in the female F2 generation during the ovarian cycle was investigated. We subjected pregnant females to daily 1-hour immobilization stress from the 15th to the 19th days of pregnancy. Further, family groups were formed from prenatally stressed and control male and female rats of the F1 generation: group 1, the control female and male; group 2, the control female and the prenatally stressed male; group 3, the prenatally stressed female and the control male; group 4, the prenatally stressed female and male. The females of the F2 generation born from these couples were selected into four experimental groups in accordance with the family group. At the age of 3 months, behavior of rats was studied in the "open field" test in two stages of the ovarian cycle - estrus and diestrus. After 7-10 days, the rats were decapitated and the neocortex, hypothalamus and hippocampus were selected to determine the level of diene and triene conjugates, Schiff bases and the degree of lipid oxidation (Klein index). In F2 females with one prenatally stressed parent, there was no interstage difference in locomotor-exploratory activity and anxiety. If both F1 parents were prenatally stressed, female F2 rats retained interstage differences similar to the control pattern, while their locomotor-exploratory activity and time spent in the center of an "open field" decreased in absolute values. In the neocortex of F2 females in groups with prenatally stressed mothers, the level of primary LP products decreased and the level of Schiff bases increased in the estrus stage. In the hippocampus of F2 females in the groups with prenatally stressed fathers, the level of Schiff bases decreased in the estrus stage, and the level of primary LP products increased in group 2 and decreased in group 4. In the hypothalamus of F2 females in the groups with prenatally stressed mothers, the level of Schiff bases increased in the estrus stage and decreased in the diestrus; in addition, in group 3, the level of primary LP products in the estrus stage increased. Thus, we demonstrated the influence of prenatal stress of both F1 mother and F1 father on the behavior and the level of LP in the neocortex, hippocampus and hypothalamus in female rats of the F2 generation in estrus and diestrus., Competing Interests: The authors declare no conflict of interest., (Copyright © AUTHORS.)

The activity of glutathione-associated antioxidant enzymes in subcellular fractions (cytosolic, mitochondrial, and cell nucleus fractions) was investigated in the liver of adult male Wistar rats born after prenatal stress was. Two groups of animals were studied in the experiment: (1) control group included - animals was born by intact mothers, and (2) prenatal stress group included animals whose mothers were subjected to immobilization stress in high-light conditions from the 15th to the 19th day of pregnancy. The activity of glutathione peroxidase (EC 1.11.1.9) in prenatally stressed animals decreased in the fractions of nuclei and mitochondria compared to the control group, while the activity of glutathione reductase (EC 1.8.1.7.) increased in the same subcellular fractions. The activity of glutathione transferase (EC 2.5.1.18) in prenatally stressed rats reduced in the cytosol and mitochondrial fractions as compared to control group. Redistribution of the antioxidant enzyme activity in the cytosol, the fraction of nuclei and the mitochondrial fraction of liver tissue may contribute to the formation of the pathological phenotype of prenatally stressed offspring.

We studied the influence of late prenatal stress on free radical oxidation processes in Sprague-Dawley rats cortex, striatum, hippocampus, hypothalamus proteins. It was shown that after prenatal stress most changes were observed in hypothalamus and hippocampus. It was shown that in hypothalamus spontaneous oxidation level increased, but level of induced oxidation decreased, the opposite changes were found in hippocampus. Simultaneously minor changes of protein modification were observed in cortex and striatum. It was shown that prenatal stress changed both correlation of proteins free radical oxidation in studied structures and values of these data regarding to control. In test of "open field" motor activity in rats after prenatal stress decreased and time of freezing and grooming increased; opposite, in T-labyrinth motor activity and time of grooming in rats after prenatal stress increased, but time of freezing decreased.

Processes of free radical oxidation of protein, lipids, and activity of superoxiddismutase in neurons and glial cells of the rat brain cortex in ontogenesis and after prenatal stress. Irrespective of age, the level of free radical oxidation of lipids and proteins in neurons is higher in comparison with the glia. The same was found in the study of superoxiddismutase activity. After prenatal stress, the level of free radical oxidation of lipids is reduced both in neurons, and in the glia. On the contrary, the contents of oxidation of proteins rises in neurons on the average fourfold. Activity of superoxiddismutase in animals who had suffered from prenatal stress is considerably reduced in neurons remaining unchanged in glial cells.