[ON THE INFLUENCE OF PRENATAL HYPOXIA ON FORMATION OF THE OREXINERGIC SYSTEM AND SLEEP-WAKEFULNESS CYCLE IN EARLY POSTNATAL ONTOGENESIS OF RATS].

The role of orexin in the organization of sleep-wakefulness cycle (SWC) is well known. The aim of this study was to examine the terms of formation of the orexinergic system in the rat postnatal ontogenesis and to assess the role of orexin A in SWC organization under normal conditions and after prenatal hypoxia realized on days 14 and 19 of the embryogenesis. SWC was investigated in 30-day-old rats with elect- rodes implanted into the somatosensory and occipital cortex. Immunoreactivity in the orexinergic structures of the lateral hypothalamus was also studied. It was shown that in the control 14-day-old animals the orexinergic structures were at the formation stage whereas in the 30-day-old ones they were already formed as in adults. In the 14-day-old rats prenatal hypoxia evoked retardation of the orexinergic system for- mation terms. In the 30-day-old rats the orexinergic system activity after hypoxia was increased, with hypoxia on day 19 activating this system stronger than hypoxia on day 14 of gestation. These changes were reflected in the SWC formation in the 30-day-old rats as shortening of the slow-wave phase of sleep, increase in the fitful sleep and in the number of transitions from the slow-wave to the fast-wave phase of sleep. The results obtained are discussed in the light of the adaptation-compensatory role of the orexinergic system in the postnatal ontogenesis after prenatal damage affecting the central neural system.

[Raction of dopaminergic and vasopressinergic systems in sleep deprivation in rats].

Six hours sleep deprivation experiments were carried out on rats after threefold injection of D1 dopamine receptor antagonist SCH 39 166. Immunohistochemical study of striatum revealed the increase in D1 and D2 dopamine receptor and glutamate immunoreactive material during the sleep deprivation and 2 h of postdeprivation period. The level of AMPA glutamate receptors increased under the sleep deprivation and decreased in the postdeprivation period. The data obtained are discussed in association with dynamic of changes of vasopressin immunoreactivity in neurosecretory supraoptical and paraventricular nuclei of hypothalamus in these experiments and in experiments without D1 receptor antagonist pretreatment.

[On filo- and ontogenetic development of dopaminergic regylation of wakefulness-sleep cycle in vertabrates].

The comparative immunohistochemical researches of dofamine containing neurons and fibers are carried uot in telencephalic and diencephalic departments of the brain in different vertebratts (adults rats, rats aged 14 and 30 days and frogs). For analysis of quantitative changes dynamics in thyrozinhydroxylase, D1 and D2 immunoreactive material in sleep-wakefulness cycle the model of sleepdeprivation is used. There are found the facts of morphofunctional correlations in the reactions of dophaminergic system during ontogeny and phylogeny. Besides, the pharmacological effects of dofamine agonist and antagonists on the sleep-wakefulness cycle in young rats and in frogs are shown. So, dopamine and its agonist apomorphine increase in sleep-wakefulness cycle duration of sleep-like state ofcataplexy (homolog of the sleep) in frogs, in 30-day-old rats it increase the share of wakefulness and catalepsy. D1 receptors antagonist (SCH 23390) adminisrated to frogs, caused increase of wakefulness and catatonic type states duration, where as D2 receptors antagonist (apomorphine) increased cataleptic condition. Administration of dopamine antagonist (haloperidol) to 30-day-old rats previously causes the increase of cataleptic state, after which the slow wave sleep state is enhanced. The questions of phylo-, ontogenetic formation of dopaminergic system regulating role in sleep-wakefulness cycle, when transition mainly from neurosecretory diencephalic influences of dophamine to the mainly neurotransmittory functins of telencephalic regions occured, is discussed.

The dopaminergic system of the telencephalo-diencephalic areas of the vertebrate brain in the organization of the sleep-waking cycle.

The aim of the present work was to study the involvement of the dopaminergic system of the telencephalic and diencephalic areas of the vertebrate brain in the organization of the sleep-waking cycle in cold-blooded and warm-blooded vertebrates. Immunohistochemical studies of tyrosine hydroxylase content, this being the key enzyme in dopamine synthesis, in the striatum, supraoptic and arcuate nuclei, and zona incerta of the hypothalamus of sturgeon and mammals (rats) of three age groups (14 and 30 days and adults), in conditions of tactile and sleep-deprivation stressors. In fish, transient stress was followed by the detection of tyrosine hydroxylase-immunoreactive cells in all parts of the brain. In prolonged stress, tyrosine hydroxylase-immunoreactive cells and fibers were not found in the forebrain, though they were well represented in the hypothalamic nuclei. In 14-day-old rat pups, 2-h sleep deprivation increased the tyrosine hydroxylase content of fibers in the caudate nucleus and cells in the zona incerta of the hypothalamus, while 30-day-old animals subjected to 6-h sleep deprivation showed increases in tyrosine hydroxylaseimmunoreactive material contents in cells in the paraventricular nucleus and decreases in the quantity in fibers. In adult rats, the arcuate nucleus and zona incerta showed decreases in the content of tyrosine hydroxylase-immunoreactive material on the background of sleep deprivation, with increases during postdeprivation sleep. These data are discussed in the light of the phylo- and ontogenetic development of the neurosecretory and neurotransmitter functions of the dopaminergic system in the evolutionarily ancient diencephalic and evolutionarily young telencephalic areas of the vertebrate brain as major systems triggering and maintaining the functional states of the body during the sleep-waking cycle.

[Dopaminergic system in the telencephalic and diencephalic brain regions in vertebrates in the sleep-wakefulness cycle organisation].

The aim of our study was to investigate the role of dopaminergic system in telencephalic and diencephalic brain regions of vertebrates in sleep-wakefulness cycle. The level of thyrosine-hydroxylase--the main enzyme in dopamine synthesis--was measured in striatum, zona inserta supraoptic and arcuate nuclea of hypothalamus in fish (Acipenceridae) and in mammals (rats) in ontogenesis (14-, 30-day old rats and adult animals) under tactile and sleep deprivation stresses. The thyrosine-hydroxylase-immunoreactive cells were revealed in all brain regions of fishes after a short-term stress. In the group after longtime stress, the thyrosine-hydroxylase-immunoreactive cells and fibers were almost absent in anterior brain but were found in hypothalamic nuclea. At 14-day old rats, 2-hour sleep deprivation caused increasing of thyrosine-hydroxylase-immunoreactivity both in fibers of caudate nucleus as well as in cells of the zona inserta. A 6-hour deprivation caused increasing of thyrosine-hydroxylase-immunoreactive material level in cells of zona inserta and decreasing it in fibers of 30-day old rats. In adult rats, the level of thyrosine-hydroxylase-immunoreactive material decreased in nucleus arcuatus and zona inserta after sleep deprivation and increased after sleep. Data obtained are discussed in terms ofphylo- and ontogenetic development of neurosecretory and neurotransmitter functions of dopaminergic system in evolutionary old diencephalic and evolutionary young telencephalic brain regions of vertebrates, which are the important systems of starting and maintenance of some functional conditions of the organism in sleep-wakefulness cycle.

[Diencephalo-telencephalic changes of tyrosine hydroxylase in rats and common frogs (Rana temporaria) after sleep deprivation].

Based on sleep deprivation-produced changes of electrographic parameters of the wakefulness--sleep cycle (WSC) in rats and common frogs, dynamics of activity of tyrosine hydroxylase, the key enzyme of dopamine synthesis, was studied immunohistochemically in substantia nigra and nigrostriatal pathway in rats and in striatum, paraventricular organ, and extrahypothalamic pathways in frogs. There are revealed changes in dynamics of tyrosine hydroxylase in rats and in common frogs after the 6-h sleep deprivation and after 2 h of postdeprivation sleep. This allows determining the degree of participation of corticostriatal neuroregulatory and hypothalamo-pituitary neurosecretory systems and their role in regulation of WSC. Possible evolutionary peculiarities of morphofunctional differences in homoiothermal and poikilothermal animals are discussed.

Effect of Hypericum extract on the hypothalamic-pituitary-adrenal system in rats.

We studied the effect of Hypericum extract on activity of the hypothalamic-pituitary-adrenal system in rats. In rats exposed to stress after a 30-day daily oral treatment with Hypericum extract, the weight of the adrenals and ACTH concentration were lower than in controls. Hence, treatment with Hypericum extract improved resistance to stress and prevented exhausting of the hypothalamic-pituitary-adrenal system.

[The direct activating effect of a nonapeptide neurohormone (vasotocin) on the thyroid and interrenal glands of sturgeons in in-vitro experiments]. / Neposredstvennoe aktiviruiushchee vliianie nonapeptidnogo neirogormona (vazototsina) na shchitovidnuiu i interrenalovuiu zhelezy osetrovykh ryb v opytakh in vitro.

An in-vitro effect of nonapeptide neurohormone vasotocin on thyroid and interrenal glands was studied in hybrid of Siberian and Lena sturgeons [correction of salmons] at light microscopy level using morphometric method. At a concentration of 0.1 and 1 nmol/l vasotocin was shown to exert undirectional stimulating effect on the thyroid and interrenal gland functions. In the presence of vasotocin at a concentration of 1 nmol/l in culture media the activity of glands is even more pronounced than under the influence of adenohypophyseal hormones, adrenocorticotropic (8 x 10 ng/ml) and thyrotropic (5 ng/ml).

The hypothalamo-hypophyseal system in Acipenseridae. XI. Morphological and immunohistochemical analysis of nonapeptidergic and corticoliberin-immunoreactive elements in hypophysectomized sterlet (Acipenser ruthenus L.).

The regeneration of the hypothalamo-hypophyseal system (HHS) has been studied in the sterlet following hypophysectomy (HypoX). Significant portions of nonapeptide and corticoliberinergic (CRH) neurosecretory cells (NSCs) underwent degeneration. Surviving NSCs had a great regenerative ability; damaged axons formed anew, uncharacteristicly for intact fishes, axovasal and axoventricular contacts. There are some specific features of the reorganization of the ANHyp in sterlet after HypoX: (a) blood capillaries from the meninges penetrate deep into the wall of the infundibular recess and form unusual axovasal contacts; (b) "neurovascular regeneratory complexes" appear; (c) single CRH-immunoreactive axons grow into the meninges. Morphological data show progressive appearance of dendroventricular contacts in the preoptic nucleus, formation of new axoventricular and axovasal contacts, and activation of surviving NSCs after HypoX. An ability to recognize HHS to release neurohormones into the CSF and bloodstream is suggested.

[Nontraditional "large-cell" neuroendocrine formations (accessory nuclei) in the brain of Anamnia and Amniota]. / Netraditsionnye "krupnokletochnye" neironnye formatsii (dobavochnye iadra) v golovnom mozgu nekotorykh Anamnia i Amniota.

Using immunochemical PAP-method nonapeptidergic neuroendocrine formations in the hypothalamus and adjacent brain areas of fishes (the sterlet Acipenser ruthenus, the shark Scylliorhinus canicula), amphibians (the frog Rana temporaria), reptiles (the snake Natrix natrix), mammals (rats and dogs) and human have been studied. In Amniota and human accessory nuclei (AN) in addition to main "magnocellular" nuclei (supraoptic, postoptic and paraventricular) were discovered. Two AN, circular and dorsolateral ones, were found in snakes, and circular, dorsolateral, forniceal and extrahypothalamic AN were revealed in rat, dog and human brain. In Anamnia, sharks and frogs, in contrast to sterlets, the dorsolateral sub-nucleus inside preoptic nucleus was identified. AN similarity in the phylogenetic row of vertebrates and mechanisms of AN creation in phylo- and ontogenesis were discussed.

[The reaction of the thyroid in the frog Rana temporaria to arginine-vasotocin administration]. / Reaktsiia shchitovidnoi zhelezy liagushki Rana temporaria na vvedenie arginin-vazototsina.

Using morphometric technique, it has been shown that single and especially three successive injections of a hypothalamic nonapeptide neurohormone, arginin-vasotocin (5.10(-9) M/kg of body weight) affect functional activity of the thyroid gland in sexually mature male frogs which had been subjected to hypophysectomy 10 or 60 days before neurohormonal treatment. These data presumably confirm a hypothesis about the direct para-adenohypophysial influence of the hypothalamic nonapeptide neurohormone on the peripheral endocrine glands, particularly, the thyroid one.

[The direct stimulating effect of arginine vasotocin on the functional activity of the interrenal gland in the frog Rana temporaria]. / Priamoe stimuliruiushchee vliianie arginin-vazototsina na funktsional'nuiu aktivnost' interrenalovoi zhelezy liagushki Rana temporaria.

Using radioimmunoassay it has been detected that both nonoperated and hypophysectomized, lacking endogenous ACTH, frogs injected one or three times with arginine vasotocin (5.10(-9) M/kg b. w.) show a statistically significant increase of plasma corticosterone level as compared with that in control animals and frogs injected with Ringer solution. The level of 11-hydroxycorticosteroids (fluorometric determination) in the interrenal gland decreases significantly only in animals three times injected with arginine vasotocin. It is assumed that arginine vasotocin produces a direct stimulatory effect on corticosteroid-producing cells of the frog interrenal gland.

[Morphofunctional research on the interrenal gland of the frog Rana temporaria following arginine vasotocin administration]. / Morfofunktsional'noe issledovanie interrenalovoi zhelezy liagushki Rana temporaria posle vvedeniia arginin-vazototsina.

Studies have been made of the effect of injections of hypothalamic nonapeptide neurohormone, arginine vasotocin, on functional condition of the interrenal gland in mature frogs. In unoperated, sham-operated and in animals 10 days after hypophysectomy, single and especially three subsequent injections of arginine vasotocin (5 x 10(-9) M per 1 kg of the body weight) result in evident activation of glandular cells of the interrenal gland which is manifested in the increase of the volume of their nuclei and cytoplasmic area, as well as in the dilatation of the blood vessels. Activation of the interrenal gland in hypophysectomized frogs, which lack endogenous ACTH, indicate the direct para-adenohypophyseal influences of nonapeptide hypothalamic hormones on the activity of glandular cells in the peripheral endocrine glands, in particular, the interrenal gland of the grass frog.

A method for hypophysectomy of the sexually mature sterlet, Acipenser ruthenus L., and the state of the fish after the operation.

Hypophysectomy was performed on sexually mature sterlets, Acipenser ruthenus L., in summer and autumn. The operation usually lasted about 45 sec, but never longer than 90 sec. After the parasphenoid was stripped, an ellipsoid hole was trepanated at the level of the eyes. The hypophysis was ablated by catching its rostral end with a pincer. As the result of the extirpation of the hypophysis the majority of the specimens grew steadily lighter, and a considerable loss of the body weight as well as macroscopical changes in the internal organs were observed. The survival rate after the operation was 100% among the fish operated on in autumn and 74-81% of those operated on in summer. Histological examination verified completeness of the extirpation of the gland. The saccus vasculosus was ablated partially or fully together with the hypophysis and the bottom of the infundibulum of the diencephalon was injured in 20-25% of the animals. However, the preoptic nucleus and the proximal part of the preoptic-hypophysial tract were not damaged.

The hypothalamo-hypophysial system in acipenseridae. X. Corticoliberin-like immunoreactivity in the hypothalamus and hypophysis of Acipenser ruthenus L.

Using the unlabeled antibody peroxidase-antiperoxidase (PAP) technique at the light microscopic level the distribution of immunoreactive corticoliberin has been studied in the hypothalamus and hypophysis of the sterlet. Corticoliberin-containing cells have been revealed in the nucleus tuberalis and to lesser degree in the nucleus preopticus of the hypothalamus. The majority of labeled cells is located subependymally or between the ependymal cells. Some dendrites of corticoliberin-containing cells can be followed toward the ventricular lumen. Their axons project to the anterior neurohypophysis (proximal neurosecretory contact region) where they terminate in contact with the primary portal capillaries. Single terminals containing immunoreactive corticoliberin are seen in the roots of the posterior neurohypophysis on the border region between the neurohypophysis and the hypophysial pars intermedia, and sometimes in contact with the capillaries of the general circulation. The possible role of corticoliberin in the regulation of the function of glandular cells of both the pars distalis and pars intermedia is discussed.