[Comparative Analysis of Behavior in The Open-field Test in Wild Grey Rats (Rattus norvegicus) and in Grey Rats Subjected to Prolonged Selection for Tame And Aggressive Behavior].

The aim of this work is analysis of the open-field behavior in grey rats selected for the tame and aggressive behavior in comparison with the wild grey rats. Significant influences of the rat group factor on the 13 of 19 behavioral features studied in the open-field were found. This effect, in general, depends on existence of great differences between behaviors of the wild rats from the one hand and behaviors of the tame and aggressive rats from the other. The behaviors of the rats from the last two groups are practically identical. Multidimensional analysis confirms the distinct separation in coordinates of the two main components of the wild rat behavior from the behavior of both the tame and selectively bred aggressive rats. The first main component dimension corresponds to the grade of fear, which was significantly enhanced in the wild rats. So, in spite of the equality of behavioral aggressiveness of the wild rats and the rats selected for aggression with the glove test, the behavior of selected aggressive rats in the open-field is analogous to behavior of the rats selected for tameness. Comparison of behavioral features with the hormonal stress responsiveness allowed us to conclude that the aggressive behavior of the wild and se lected for aggression rats based on different motivational and neuroendocrine processes.

The characteristics of motor activity in ISIAH rats in an open field test are controlled by genes on chromosomes 2 and 16.

Quantitative Trait Locus (QTL) analysis was used to identify the loci of polygenic characteristics in a study of the genetic determination of the behavior of rats with inherited stress-induced arterial hypertension (ISIAH rats). Analysis was performed using males of two populations of F2 hybrids (ISIAH x WAG) of different ages: 3-4 (n = 106) and six months (n = 130). Chromosomes 2 and 16 in the young population of F2 rats showed significant associations between two characteristics of behavior in ISIAH rats and genetic loci: a) the rats' motor activity at the periphery of the open field area with loci in the regions of markers D2Rat157-D2Rat88 (LOD score 4.83; p = 0.000058) and D16Rat32 (LOD score 3.71; p = 0.00023). Together, these two loci accounted for 42.9% of the trait variability; b) the rats' motor activity during the first minute of the open field test and loci in the region of the marker D16Rat58 (LOD score 3.78; p = 0.00028). Results obtained by QTL analysis demonstrated a relationship between the genetic control of these traits and the animals' age.

[Learning of rats predisposed to catalepsy in Morris water test].

It was shown that GC rats predisposed to catalepsy do not differ from Wistar rats in success rate or latency (time of finding of the hidden escape platform) in the Morris water test. However, unlike Wistar, GC rats are inclined to passive drift and longer floating episodes. Rats of the MD+ strain predisposed to hyperkinesis in the form of horizontal pendulum-like movements of the head and upper limb girdle show longer latency and lower rate of successful trials than Wistar or MD-, rats selected for absence of the pendulum-like movements.

[The ISIAH rat locomotion in the open field test is under control of the genes on chromosome 2 and chromosome 16].

The QTL analysis was performed in order to identify the genetic loci that contribute to the behavior in the open field tests in the ISIAH rat strain with inherited stress-induced arterial hypertension. Two F2 populations of 3-4-month-old (n = 106) and 6-month-old (n = 130) male rats derived from a cross between the normotensive Wistar albino Glaxo (WAG) and hypertensive ISIAH rats were used in the search for the QTL. In 3-4-month-old rats, QTL were found: a) for the rat locomotion at the periphery of the open field in the region of D2Rat157-D2Rat88 markers (logarithm of odds (LOD) score 4.83; p= 0.000058) on Chr. 2 and in the vicinity of the D16Rat32 marker (LOD score 3.71; p = 0.00023) on Chr. 16. These two QTL describe the 42.9% of the trait variability. b) for the rat locomotion during the first minute of the open field test on Chr.16 near the D16Rat58 marker (LOD score 3.78; p = 0.00028). The results provided support for the existence of the age-dependent differences in the genetic control of the traits analyzed.

Functional activity of the sympathoadrenal system in hypertensive NISAG rats.

NISAG rats with stress-induced arterial hypertension are characterized by hyperactivity of the sympathoadrenal system under rest conditions and during stress exposure.

[Some neuroendocrinological changes in rats of cataleptic strain GC. Influences of ontogenesis and generation of breeding].

The content of biogenic amines: dopamine, noradrenaline and serotonine, in rats of cataleptic strain GC as compared with the control strain Wistar at the age of 1 and 5 months is decreased, the maximal decrease being found in the so-called "nervous" animals. The aldosterone content was decreased at 5 month age in the GC rats. The testosterone content at the age of 1 month in GC rats does not differ from that in Wistar rats, but at the age of 5 months it was decreased as compared to Wistar, the maximal decrease being found again in "nervous" GC rats. The data obtained point to peculiarities of ontogenetic regulation and to commonness of mechanisms of catalepsy and "nervousness" in GC rats.

Role of alpha(2A)-adrenoceptors of locus coeruleus in regulation of plasma corticosterone content in male rats.

Administration of specific oligonucleotide selectively inhibiting alpha(2A)-adrenoceptor gene expression into the locus coeruleus of male rats for 3 days activated the hypothalamic-pituitary-adrenal system, which was manifested in a rise of blood plasma corticosterone content in rats with normal and hypertrophied (after castration) adrenal glands. These data indicate that alpha(2A)-adrenoceptors of the locus coeruleus are involved in the regulation of basal plasma corticosterone content.

[The behavioral effects of a single adverse exposure in a number of rat generations: the role of maternal glucocorticoids]. / Povedencheskie éffekty odnokratnogo neblagopriiatnogo vozdeistviia v riadu pokolenii krys: rol' gliukokortikoidov materi.

The ionizing irradiation of rat fetuses during the last third of intrauterine development increased blood corticosterone level adulthood and decreased the open field locomotion of their adult offsprings of the next first nonirradiated generation. Treatment of the pregnant rats with glucocorticoids also decreased the offspring locomotion. Irradiation of fetuses in the middle of embryogenesis decreased blood corticosterone level in adulthood and shortened the open-field freezing reaction of their adult offsprings of the next first nonirradiated generation. Adrenalectomy of females before mating decreasing the blood corticosterone level had a similar effect on freezing duration of their adult offsprings. Irradiation of the ancestors within the last third of their intrauterine development had no effect on blood corticosterone level of their adult offsprings of the first generation and produced no behavioral alterations in their descendants of the next second nonirradiated generation. Irradiation of the ancestors in the middle of their embryogenesis decreased the stress-induced corticosterone response in their adult offsprings of the first generation and increased rearings and locomotion in their descendants of the next second nonirradiated generation. The data suggest that a single noxious treatment may have behavioral effects throughout two consequent generations of rats. Mother's glucocorticoid hormones may be one of the factors which transmit the effect.

[Corticosterone and testosterone in the blood of adult rats: the effects of low doses and the times of the action of ionizing radiation during intrauterine development]. / Kortikosteron i testosteron v krovi vzroslykh krys: éffekty nizkikh doz i sroka deistviia ioniziruiushchei radiatsii v period vnutriutrobnogo razvitiia.

Corticosterone levels in the blood and adrenal weights in adult rat males were increased after low-dose gamma irradiation during the last third of their intrauterine development; an increase of the dose decreased them. Decrease in testosterone levels and testis weights were dose-dependent. External and internal irradiation of females on the 11-14 days of pregnancy inhibited adrenals and increased testosterone levels and seminal vesicles weights in offspring. The changes of hormonal balance in adult animals depend on dose and period of ionizing irradiation during intrauterine development.

[The behavior of the progeny of prenatally irradiated rats]. / Povedenie potomkov prenatal'no obluchennykh krys.

Ambulation and rearing in the open field were decreased in adult male offsprings of rats which were exposed to moderate doses of gamma-irradiation during the last third of their intrauterine development. Single combined external and internal irradiation of the ancestors in the middle of the intrauterine period resulted in increased ambulation in the open field (and its decreased latency) and activity in the wheel in their adult offsprings. The obtained evidence suggests that exposure of parents to harmful factors has its impact on behaviour of offsprings depending on the characteristics of such factors.

[The effect of the prolonged experience of aggression and subordination on the adrenal cortical and androgenic functions of inbred male mice]. / Vliianie dlitel'nogo opyta agressii i podchineniia na adrenokortikal'nuiu i androgennuiu funktsii samtsov inbrednykh myshei.

Repeated experience of aggression and submission in daily agonistic confrontations differently changed stress response in winners and losers of CBA/Lac and C57BL/6J strains. Experience of defeats was accompanied by expressed decrease of testosterone level in losers. Number of hemorrhages and erosions was significantly more in losers when compared to winners. Some strain differences in stress reaction were found in winners and losers as compared to controls.

[The significance of aggressive relationships in a micropopulation in regulating catecholamines in the adrenals of male laboratory mice]. / Znachenie agressivnykh otnoshenii v mikropopuliatsii v reguliatsii katekholaminov v nadpochechnikakh samtsov laboratornykh myshei.

Levels of adrenaline and noradrenaline were changed in the adrenal glands of 6 male mice genotypes during both the period of intense intermale relationships and the period of absence of fights among the males. The character of the catecholamines changes depended on the animal genotype. Significant interlinear correlations were found among the amounts of adrenaline, noradrenaline and dopamine.