Perinatal Stressors as a Factor in Impairments to Nervous System Development and Functions: Review of In Vivo Models.

The human body is faced with stress throughout ontogeny. At the stage of intrauterine development, the mother's body serves as a source of resources and most of the humoral factors supporting the development of the fetus. In normal conditions, maternal stress-related humoral signals (e.

Beneficial effects of xenon inhalation on behavioral changes in a valproic acid-induced model of autism in rats.

Background: Xenon (Xe) is a noble gas that has been used for the last several decades as an anesthetic during surgery. Its antagonistic effect on glutamate subtype of NMDA (N-methyl-D-aspartate) receptors resulted in evaluation of this gas for treatment of CNS pathologies, including psychoemotional disorders. The aim of this study was to assess the behavioral effects of acute inhalation of subanesthetic concentrations of Xe and to study the outcomes of Xe exposure in valproic acid (VPA)-induced rodent model of autism.

[Food-derived opioid peptides and their neurological impact].

In this review the up-to-date literature data about exorphins are analysed. Exorphins are short opioid-like food-derived peptides. Different reports about their physiological impact in animals and humans are reviewed with focus on neurotropic effects.

[Comparative analysis of the maternal motivation expression in WAG/Rij and Wistar rats in the place preference and open field tests].

Maternal behavior in females of WAG/Rij and Wistar rats was compared in the place preference test from 2 to 8 days after delivery, as well as in the open field test from 4 to 6 days after delivery. In females of WAG/Rij rats compared with females of Wistar rats weaker expression of maternal motivation has been revealed in both tests: they spend less time in the compartment associated with pups. Moreover, in females of WAG/Rij rats, number of approaches to pups, number of pup-carryings and time spent with pups (time of contacts) were less than in females of Wistar rats.

[Reverse learning in WAG/Rij rats with depression-like behavior].

Learning and reverse learning in a complex maze, behavior in the open field test, novelty-suppressed feeding test, and forced swimming test were studies in WAG/Rij and Wistar rats. As compared with Wistar rats, WAG/Rij rats more slowly learned the spatial task, more slowly performed in the learning and reverse learning tasks, and made more errors in the complex maze (18% of WAG/Rij rats didn't reach learning criterion). Moreover, WAG/Rij rats exhibited reduced grooming reactions in the open field test, longer latency of approaching to food in the novel open field, reduced amount of food consumed in the home cage in the novelty-suppressed feeding test, and increased immobility time in the forced swimming test.

[Selective D1-receptor antagonist SCH23390 decreases maternal reactions in rats upon acute and chronic injections in postpartum period].

The influence of the D1-receptor antagonist SCH23390 on the maternal behavior of female rats has been studied. It is established that a comparatively high dose of the drug (acute injections) significantly decreases both the locomotor activity and manifestations of the parental care. Lower dosages do not affect the locomotor activity, but still suppress the maternal behavior (after both acute and chronic injections of SCH23390).

Effect of single and repeated injections of selective D2-antagonist clebopride on maternal behavior of albino rats.

This study examined the effect of clebopride at low concentration that did not modify the motor activity on the parental care in female albino rats. Single injection of the drug attenuated the parental care reactions on postinjection minute 20, but not one day thereafter. The daily injection of the drug during the post partum period (1-6 days) resulted in significantly more pronounced and stable effects.

Behavioral effects of original tetrapeptide, an analog of N-terminal nociceptin fragment.

The study examined the effect of an analog to N-terminal nociceptin fragment AcOH×Phe-Gly-Gly-Phe-NH(2) on the behavior of albino rats. This tetrapeptide (5 μg/kg intraperitoneally) significantly enhanced motor and exploratory activity in mature rats and in 42-day pups and produced opposite effects in 21-day rat pups, which attests to the complex dynamics of maturation of nervous structures involved in the realization of nociceptin action.

The effect of haloperidol on maternal behavior in WAG/Rij rats and its consequences in the offspring.

Haloperidol treatment during pre- and post-natal period affects maternal behavior and this may have long-term effects on the offspring. We examined whether early haloperidol administration to Wistar-Albino-Glaxo dams from Rijswijk (WAG/Rij) and in Wistar control rats would affect maternal care and as a consequence, seizure susceptibility and behavior in the WAG/Rij's offspring at 3-4 months of age. Nursing dams of this well-validated genetic animal model of absence epilepsy and control dams were injected with haloperidol or saline at PPD 1 to 6.

[The role of dopamine and opioid systems in the regulation of maternal behavior].

This review describes in detail the different components and neuroanatomical basis of maternal behavior and also methodological approaches to investigation of parental reactions. The contributions of some endocrinal and neuromediator brain systems (in the first place, opioid and dopaminergic) to the regulation of maternal behavior are reported. The influences of ligands of opioid and dopamine receptors on the expressions of paternal reactions are analyzed especially.

Role of the brain dopaminergic and opioid system in the regulation of "child's" (maternal bonding) behavior of newborn albino rats.

Administration of D(2) receptor antagonist clebopride in a dose not affecting locomotor activity was followed by a decrease in maternal bonding behavior of 10-day-old and 15-day-old albino rat pups. D(1) receptor antagonist SCH23390 had a stimulatory effect only on the behavior of 10-day-old newborns. Opioid peptide β-casomorphin-7 abolished the effect of clebopride in rat pups of the older age group.

[Maternal behavior of WAG/Rij strain rats in normal conditions and during intervention in the activity of dopaminergic brain system].

Lactating dams of WAG/Rij and Wistar rat strains were repeatedly placed on the "open field" arena with their pups (4-9 postnatal days). In these conditions WAG/Rij rats showed significantly poorer maternal behavior and were slower in forming pup location response. These results add to the notion of disorders in the activity of the nervous system of WAG/Rij rats (as genetic models for absence epilepsy).

[A new method of investigation of "child's" behavior (infant-mother attachment) of newborn rats].

A new method of studying "child's" (maternal bonding) behavior of newborn rats was developed. The efficiency of the method was proved in estimation of dopaminergic control of the infant-mother attachment. Selective D2-antagonist clebopride applied in subthreshold for motor activity doses caused a decrease in aspiration of pups to be in contact with a dam.

[Effects of several exorphins and endorphins on the escape reaction of the cockroach Periplaneta americana under elevated temperature conditions].

The ability of several alimentary opioid peptides (exorphin C, rubiscolin-5, cytochrophi-4) and endorphins (met-enkephalin, dynotphin A(1-10), beta-neoendorphin) to change the escape reaction of the cockroaches Periplaneta americana at their placement into a hot chamber was studied. The ED50 values increasing twice the insect stay time in the hot chamber as well as duration and dynamics of the effects were determined. It has been shown that ED5 decreases statistically significantly with increase of the length of the peptide molecule and its affinity of duration of the effects and to an increase of their affinity to delta-receptors - to prolongation of the reaction (more than150 min).

[Delayed effect of exorphins on learning of albino rat pups].

The delayed effect of food-derived opioid peptides (exorphins) after chronic administration on postnatal days 1-14 on the learning of albino rat pups has been studied. Heptapeptide YPFPGPI (beta-casomorphin-7), pentapeptide YPLDL (rubiscolin-5) and pentapeptide YPISL (exorphin C) improved the development of the conditioned foraging reflex in a complex maze. Hexapeptide PFPGPI lacking the N-terminal tyrosine proved inefficient.

Activation of maternal behavior of albino rats after combined treatment with dopamine and opioid receptor antagonists in low doses.

We studied the effect of D1/D2 antagonist haloperidol on maternal motivation in nursing albino rats. Haloperidol in a dose of 0.2 mg/kg significantly attenuated parental reactions and motor and exploratory activities.

Effect of opioid antagonist naloxone on maternal motivation in albino rats.

We studied the effect of nonselective antagonist of opioid receptor naloxone on the behavior of albino female rats on days 4-6 after delivery. Intraperitoneal injection of naloxone (5 mg/kg) significantly stimulated maternal reactions (increased the number of approaches to pups, decreased the latency of their transfer into new location). Intranasal naloxone (1 mg/kg) produced similar changes.

[Influence of acute and chronic administrations of beta-casomorphins on the maternal motivation in albino rats].

The influence of food-derived opioid peptides beta-casomorphines on the manifestation of nursing albino rats maternal behavior was investigated. It was shown that both acute and chronic (during the postnatal period) administration of beta-casomorphin-7 (Tyr-Pro-Phe-Pro-Gly-Pro), the typical representative of this group of peptides, decreases the level of the parental motivation. The effects of beta-casomorphin-7 were naloxone-dependent; N-terminal-reduced analogues had a significantly lesser activity.

[Behavioural effects of beta-casomorphin-7 in its intranasal administration].

Intranasally administrated natural opioid peptide beta-casomorphin-7 (doses 0.001, 0.005, 0.

[The neurotropic activity of food-derived opioid peptides beta-casomorphins].

In the review the history of food-derived opioid peptides beta-casomorphins (beta-cas) discovery is given. The beta-cas formation in gastrointestinal tract during the beta-casein degradation and the following penetration into the blood are described, in the first place in newborn mammals. The attention is focused on neurotropic activity of beta-cas: their influence on the pain sensitivity, locomotion, anxiety and learning of experimental animals.

Gaseous superoxide potentiation of the effect of nonnarcotic analgesics in low doses.

The action of inhalation of gaseous superoxide on the effects of low doses of nonnarcotic analgesics was studied on volunteers in the little finger compression test. After administration of placebo, inhalation of gaseous superoxide produced a negligible transient decrease in pain tolerance threshold. Inhalation of gaseous superoxide potentiated the effects of threshold doses of novalgin and aspirin and prolonged their action, but did not modulate the analgesic effect of diclofenac.