Early and Delayed Effects of Hypoxia during the Infantile Period on Behavioral and Hormonal Reactions of Rats

We studied the early and delayed effects of hypoxia during the infantile period on the behavioral reactions and corticosterone concentration in male rats. The elevation of corticosterone concentration, decrease in the immobility time (forced swimming test), and increase in the nociceptive response (formalin test) were observed in 7-day-old rats immediately after hypoxia. Adult animals exposed to hypoxia at the age of 7 days exhibited elevated basal corticosterone level and lengthened immobility time. Hypoxia had the same effect on plasma corticosterone concentration in 7-day-old and adult rats. Changes in corticosterone concentration after forced swimming were shown to differ in hypoxic animals and non-hypoxic specimens. Studying the dynamics of age-related variations in the test parameters will contribute to the understanding of pathogenetic mechanisms and development of new methods for pharmacological correction of postnatal changes in CNS after hypoxia during early ontogeny.     

Transgeneration Effects of Antenatal Acute Hypoxia during Early Organogenesis

We studied the effect of acute hypobaric hypoxia in early organogenesis on physiological and behavioral parameters of second-generation albino rats. Antenatal acute hypoxia was followed by physical and sexual retardation, increase in the mortality rate, and behavioral changes in second-generation animals (hypoactivity of males and females on day 22 of life and hyperactivity of males on day 57 of life). Second-generation animals exhibited no gender differences in body weight and horizontal and vertical locomotor activity. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 146, No. 10, pp. 364–366, October, 2008     

Delayed Nootropic Effects of Arginine Vasopressin after Early Postnatal Chronic Administration to Albino Rat Pups

Intranasal administration of arginine vasopressin (10 μg/kg) to albino rat pups had a strong nootropic effect during training with positive and negative reinforcement. This effect was different in animals of various age groups: training with positive reinforcement was improved in “adolescent” rats and pubertal animals, while during training with negative reinforcement, the nootropic effect of the peptide was more prolonged and persisted also in adult animals.     

Peculiarities of Immediate Response of Respiratory Chain Enzymes in Rat Cerebral Cortex to Hypoxia

Bulletin of Experimental Biology and Medicine - We performed a complex study of the dependence of immediate reaction of catalytic subunits in mitochondrial enzymes (NDUFV2, SDHA, Cyt b, COX1, and...     

Effects of Vibrissectomy during Early Postnatal Ontogenesis in Rat Pups on Behavioral Development

The effects of daily trimming of the whiskers in rat pups from day 2 or day 9 to day 20 on eye opening time and the formation of early behavioral reactions, i.e., walking, rearing, grooming, and manipulatory activity, were studied in rat pups subjected to deprivation and siblings reared with them. Rat pups subjected to vibrissectomy from day 2 of life and their siblings showed acceleration of eye opening, maturation of grooming, and rearing without support; the formation of manipulatory activity was delayed, as were changes in the structures of correlational relationships between the times at which behavioral reactions formed and eye opening occurred. Vibrissectomy from day 9 of life eliminated most correlational relationships in deprived animals without impairing the dynamics of the development of early behavioral reactions. Siblings showed delayed formation of manipulatory activity, though changes in the structure of correlational relationships were less significant than in deprived animals.     

不同应激方式对模拟高原环境下大鼠海马单胺递质的影响

目的:探讨心理和生理应激对模拟高原低压低氧环境下的大鼠海马单胺递质含量的影响。方法:雄性SD大鼠随机分为对照组(Con组)、低氧组(Hy组)、心理应激(2次/d)组(Ps1组)、心理应激(2次/d×2天)组(Ps2组)、心理应激(2次/d) 低氧组(Ps1 Hy组)、心理应激(2次/d×2天) 低氧组(Ps2 Hy组)、生理应激(2次/d)组(Ph1组)、生理应激(2次/d×2天)组(Ph2组)、生理应激(2次/d) 低氧组(Ph1 Hy组)和生理应激(2次/d×2天) 低氧组(Ph2 Hy组)。心理和生理应激都采用旁观电击(CB)的方法。用高效液相色谱-电化学检测法(HPLC-ECD)测定用推挽灌流收集的海马灌流液中的去甲肾上腺素(NE),多巴胺(DA)和5-羟色胺(5-HT)的含量。结果:①与Con组比较,Hy、Ps1 Hy和Ph2 Hy组的NE含量均显著降低(P<0.01,0.05和0.01);与Hy组比较,Ps2 Hy和Ph1 Hy组的NE含量均显著增高(P<0.01和0.05)。②与Con和Hy组比较,Ph1 Hy组的5-HT含量均显著升高(P<0.01和0.05)。③与Con和Hy组比较,Ph1 Hy组的DA含量均显著升高(P<0.01)。结论:心理和生理应激皆能显著影响低压低氧环境下大鼠海马单胺递质的含量。     

Early and Delayed Effects of Carboplatin on the Blood System

Carboplatin injected intravenously in a maximum permissible dose to Wistar rats inhibited erythro- and granulocytopoiesis in the bone marrow, caused hyporegenerative anemia, leukopenia, and thrombocytopenia in the peripheral blood, led to hypoplasia of the thymus and spleen, and produced moderate apoptosis-inducing effects. These effects were observed within the first month after treatment. In mice carboplatin induced chromatid aberrations in the bone marrow and increased the count of erythrocytes with micronuclei. Moderate hypoplasia of erythro- and granulocytopoiesis and accelerated involution of the thymus were observed 3 and 6 months after cytostatic treatment. Our results indicate that carboplatin possesses higher myelotoxic activity compared to cisplatin.     

Effects of Preconditioning on the Resistance to Acute Hypobaric Hypoxia and Their Correction with Selective Antagonists of Nicotinic Receptors

Hypobaric hypoxic preconditioning increased the resistance of low resistant and highly resistant rats to acute hypobaric hypoxia at a critical height. Intergroup differences in the resistance of rats to acute hypobaric hypoxia were not observed after hypobaric hypoxia and one variational series with a wide range of resistance (4.5-24.5 min) appeared. Methyllycaconitine, an antagonist of subtype α₇ nicotinic cholinergic receptors, abolished the influence of hypobaric hypoxia on low resistant rats, but had no effect on highly resistant animals. Mecamylamine, a preferential antagonist of subtype α₄β₂ and α₃-containing cholinergic receptors, did not modulate the effect of hypobaric hypoxia. By contrast, hypobaric hypoxia abolished the effect of mecamylamine on the resistance of rats that were not trained under conditions of hypobaric hypoxia (low resistant and highly resistant animals with low sensitivity to hypobaric hypoxia). We conclude that the same effect of hypobaric hypoxia is mediated by various mechanisms, which involve different nicotinic cholinergic receptors. They differ from the resistance mechanisms in non-trained rats.     

Delayed Effects of Surgery during Early Pregnancy on Brain Development in OXYS Rats

Neuroscience and Behavioral Physiology - The aim of the present work was to study the effects of stress induced by surgical interventions in early pregnancy on neuron density in the prefrontal...     

Effect of Prenatal Hypobaric Hypoxia on Glutamatergic Signal Transduction in Rat Brain

Ca²⁺-mediated signal transduction of group I metabotropic glutamate receptors (ImGluR) was studied in the brain of young (15 days) and old rats (90 days) exposed to severe hypobaric hypoxia on gestation days 14–16. Changes in the concentration of bound intracellular Ca²⁺ (Ca²⁺ response) were evaluated after repeated application of a selective ImGluR agonist 3,5-dihydroxyphenylglycine (DHPG) to cultured brain slices. Primary application of DHPG for 2 min induced a negative Ca²⁺ response in slices from 15-day-old intact animals, while repeated application caused a positive response. In slices from 90-day-old control animals, both responses were negative. In slices from rats of both age groups subjected to severe prenatal hypobaric hypoxia, both responses were mainly positive, but short-term negative components were present in adult animals. Our results suggest that severe hypobaric hypoxia changes the balance between the two constitutive signal pathways triggered by ImGluR (inosine triphosphate and diacylglycerol pathways). This procedure is followed by the increased influx of extracellular Ca²⁺ (as compared to Ca²⁺ release from the intracellular stores). This imbalance is particularly pronounced at the early stage of ontogeny.     

The Effects of Ante- and Postnatal Hypoxia on the Central Nervous System and Their Correction with Peptide Hormones

Ante- and postnatal hypoxia significantly worsened the postnatal development of animals. The posthypoxic behavioral model included hyperactivity and decreased learning ability, these being typical manifestations of attention deficit disorder. A peptide constellation prevented and significantly improved posthypoxic postnatal development and eliminated the majority of negative behavioral changes.     

Peptidergic Correction of the Effect of Acute Hypobaric Hypoxia in Pregnant Rats on Progeny

Acute hypobaric hypoxia of pregnant rats led to a significant delay in body weight gain, growth and time of eye opening in newborn rat pups which was paralleled by behavioral changes. Preventive intranasal instillations of peptide mixture (semax and -casomorphine-7) to pregnant females prevented the effect of hypoxia on the progeny.