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On Wistar rats in view of electrophysiological parameters after sleep deprivation (SD; awake by gentle handling method) and the subsequent postdeprivative sleep (PDS) immunohistochemical investigation of Bcl-2 and p53 peptides optical density levels in neurons of paraventricular (PVN), supraoptic (SON) and median (MnPN) hypothalamus nuclei was carried out. The Bcl-2 was increased in all nuclei both after SD and PDS. The level of p53 was increased in PVN and SON after SD and PDS, but in MnPN only on PDS. Any morphological attributes of apoptosis in the nuclei was not revealed. Obtained data testify an active role of p53 and Bcl-2 peptides in regulation of neuronal activity in hypothalamus at change of a cycle wakefulness-sleep.

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.

The dynamics of changes in electrophysiological measures of the sleep-waking cycle were analyzed in Wistar rats after 6 h of sleep deprivation by gentle waking and subsequent 9-h post-deprivation sleep. A delayed sleep "overshoot" reaction was observed 2.5-3 h after sleep deprivation, as a moderate increase in the proportions of slow-wave and fast-wave sleep in the sleep-waking cycle. Immunohistochemical studies were performed in relation to changes in the sleep-waking cycle, with the aim of identifying changes in the quantities of immunoreactive dopamine D1 and D2 receptor material and tyrosine hydroxylase, the key enzyme in dopamine synthesis in the nigrostriatal system. In conditions of sleep deprivation, the caudate nucleus showed increases in the quantities of dopamine D1 and D2 receptor material, while there was a simultaneous decrease in the amount of immunoreactive material in the substantia nigra. Post-deprivation sleep was accompanied by decreases in the quantities of immunoreactive D1 receptor material and increases in D2 receptor material in the caudate nucleus, with an increase in the quantity of immunoreactive tyrosine hydroxylase in the substantia nigra. These data provide evidence of the active role of the dopaminergic nigrostriatal system which, along with other CNS transmitter systems, supports telencephalic-diencephalic interactions, in the sleep-waking cycle.

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.

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.

The analysis of the electrophysiological features of sleep-wakefulness cycle in Wistar rats for 9h after a 6h sleep deprivation was carried out. The delay of sleep rebound (since 2.5-3 h after deprivation) was found in the form of moderate increasing of slow-wave sleep and fast-wave sleep phases. According to these sleep-wakefulness cycle changes, a quantitative immunohistochemical study of tyrosine hydroxylase: a key enzyme of dopamine synthesis--and D1 and D2 receptors in nigro-striatal projections has been performed. After sleep, an elevation of D1 receptors immunoreactivity in caudate nucleus and reduction of tyrosine hydroxylase immunoreactivity in compact part of substancia nigra was found. After postdeprivation sleep, a decrease of D1 receptors immunoreactivity and increase of D2 receptors immunoreactivity in caudate nucleus together some increase of tyrosine hydroxilase immunoreactivity in substancia nigra compacta has been observed. These data can testify about active role of dopaminergic nigrostriatal system which provide at the same time with another neurotransmitters of the central nervous system the telencephalo-diencephalic interaction in sleep-wakefulness-sleep cycle.