| a novel melatonin derivative modulates sleep-wake cycle in rats. | the aim of this study was to evaluate, in comparison with melatonin (mlt), the effects of a novel 2-melatonin derivative, having a 2-trifluoromethyl group (mltd) on the sleep-wake cycle in freely behaving rats. doses of mltd (100, 300 and 500 nmol/100 microl saline) or mlt (500 nmol/100 microl saline) replaced the i.c.v. infusion of saline during the diurnal infusion period (7:00-17:00). diurnal infusion of mltd significantly (p < 0.05) increased nrem sleep at doses of 300 and 500 nmol during th ... | 2004 | 15196675 |
| glutamatergic-receptors blockade does not regularize the slow wave sleep bursty pattern of subthalamic neurons. | the subthalamic nucleus (stn) has been implicated in movement disorders observed in parkinson's disease because of its pathological mixed burst firing mode and hyperactivity. in physiological conditions, stn bursty pattern has been shown to be dependent on slow wave cortical activity. indeed, cortical ablation abolished stn bursting activity in urethane-anaesthetized intact or dopamine depleted rats. thus, glutamate afferents might be involved in stn bursting activity during slow wave sleep (sws ... | 2004 | 15233749 |
| extracellular histamine level in the frontal cortex is positively correlated with the amount of wakefulness in rats. | histaminergic neurons have been strongly implicated in the regulation of wakefulness by activating cortical neurons. however, little is known about histamine release in the cortex during sleep-wake stages. in this study, we monitored the extracellular histamine level in the frontal cortex by in vivo microdialysis coupled with electroencephalogram and electromyogram recordings in freely moving rats. the histamine release was 3.8 times higher during wake episodes than during sleep episodes, being ... | 2004 | 15236867 |
| anatomic and functional topography of the dorsal raphe nucleus. | serotonergic systems play an important and generalized role in regulation of sleep-wake states and behavioral arousal. recent in vivo electrophysiologic recording studies in animals suggest that several different subtypes of serotonergic neurons with unique behavioral correlates exist within the brainstem raphe nuclei, raising the possibility that topographically organized subpopulations of serotonergic neurons may have unique behavioral or physiologic correlates and unique functional properties ... | 2004 | 15240351 |
| interleukin-1beta modulates state-dependent discharge activity of preoptic area and basal forebrain neurons: role in sleep regulation. | interleukin-1beta (il-1) is a pro-inflammatory cytokine that has been implicated in the regulation of nonrapid eye movement (nonrem) sleep. il-1, il-1 receptors and the il-1 receptor antagonist (ra) are present normally in discrete brain regions, including the preoptic area (poa) of the hypothalamus and the adjoining magnocellular basal forebrain (bf). the poa/bf have been implicated in the regulation of sleep-wakefulness. we hypothesized that il-1 promotes nonrem sleep, in part by altering the ... | 2004 | 15245493 |
| gaba in pedunculo pontine tegmentum regulates spontaneous rapid eye movement sleep by acting on gabaa receptors in freely moving rats. | rem-off and rem-on neurons in the brainstem are reported to regulate rem sleep, however, the detailed mechanism of generation of rem sleep is unknown. the former are continuously active except during rem sleep and an inhibitory neurotransmitter, gaba, has been implicated in mediating the inhibition for the generation of rem sleep. the rem-on neurons, on the other hand, remain inactive throughout but increase firing during rem sleep. this study was conducted to investigate if gaba in the brain ar ... | 2004 | 15246548 |
| increased wakefulness, motor activity and decreased theta activity after blockade of the 5-ht2b receptor by the subtype-selective antagonist sb-215505. | serotonin-2 receptor antagonists, like ritanserin, greatly enhance deep slow wave sleep (sws-2) and low-frequency eeg power in humans and rodents. 5-ht(2a) and 5-ht(2c) receptors may be involved in these effects, but the role of the 5-ht(2b) receptor is still unclear. to investigate the role of the 5-ht(2b) receptor in regulation of the sleep-wake cycle, the subtype-selective antagonist sb-215505 (0.1, 0.3 and 1.0 mg kg(-1) i.p.) was administered to sprague-dawley rats at light onset (beginning ... | 2004 | 15265808 |
| scatterplot analysis of eeg slow-wave magnitude and heart rate variability: an integrative exploration of cerebral cortical and autonomic functions. | to explore interactions between cerebral cortical and autonomic functions in different sleep-wake states. | 2004 | 15282999 |
| modafinil facilitates performance on a delayed nonmatching to position swim task in rats. | modafinil is a wake-promoting drug approved by the fda for the treatment of narcolepsy. recent evidence suggests that modafinil may improve learning and memory processes. to further evaluate possible cognitive properties associated with modafinil, male sprague-dawley rats were tested in a delayed nonmatching to position (dnmtp) task. a modified water maze allowed animals to make one of two choices for the location of the escape platform. each trial consisted of two swims. on the information swim ... | 2004 | 15301929 |
| influence of temporomandibular joint pain on sleep patterns: role of nitric oxide. | since nitric oxide is related to nociception and the sleep-wake cycle, this study sought to determine its involvement in the altered sleep pattern in a temporomandibular joint pain model by investigating the effect of the inhibitor of nitric oxide synthase (l-name) and that of its precursor (l-arginine). the temporomandibular joints of test animals were injected with freund's adjuvant or saline, and their sleep was recorded. the procedure was repeated after the administration of l-name and l-arg ... | 2004 | 15329374 |
| ghrh and sleep. | a significant portion of the total daily growth hormone (gh) secretion is associated with deep non-rem sleep (nrems). gh secretion is stimulated by the hypothalamic neurohormone, gh-releasing hormone (ghrh). exogenous ghrh promotes nrems in various species. suppression of endogenous ghrh (competitive antagonist, antibodies, somatostatinergic stimulation, high doses of gh or insulin-like growth factor) results in simultaneous inhibition of nrems. mutant and transgenic animals with a defect in ghr ... | 2004 | 15336237 |
| sleep and arousal mechanisms in experimental epilepsy: epileptic components of nrem and antiepileptic components of rem sleep. | neural generators related to different sleep components have different effects on seizure discharge. these sleep-related systems can provoke seizure discharge propagation during nonrapid eye movement (nrem) sleep and can suppress propagation during rem sleep. experimental manipulations of discrete physiological components were conducted in feline epilepsy models, mostly in the systemic penicillin epilepsy model of primary generalized epilepsy and the amygdala kindling model of the localization-r ... | 2004 | 15362167 |
| the metabotropic glutamate (mglu)2/3 receptor antagonist ly341495 [2s-2-amino-2-(1s,2s-2-carboxycyclopropyl-1-yl)-3-(xanth-9-yl)propanoic acid] stimulates waking and fast electroencephalogram power and blocks the effects of the mglu2/3 receptor agonist ly379268 [(-)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate] in rats. | the highly selective metabotropic glutamate (mglu)2/3 receptor agonist ly379268 [(-)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate] completely suppresses rapid eye movement (rem) sleep and strongly depresses theta (6-10 hz) and high-frequency (10-60 hz) power in the waking and nonrapid eye movement (nrem) eeg, effects consistent with depressed brain excitation (arousal). we hypothesized the selective mglu2/3 receptor antagonist ly341495 [2s-2-amino-2-(1s,2s-2-carboxycyclopropyl-1-yl)-3-(xa ... | 2005 | 15383637 |
| movement-related discharge of ventromedial medullary neurons. | studies in anesthetized animals implicate nonserotonergic cells in the ventromedial medulla (vmm) in opioid modulation of nociceptive transmission but do not reveal the conditions that engage vmm cells in unanesthetized rats. the few studies of vmm cells in unanesthetized rats show that vmm cells change their discharge across the sleep-wake cycle and during active movements. since active movements are more likely to occur during waking than sleep, state-related discharge may in fact represent mo ... | 2005 | 15385592 |
| the diurnal rhythm of hypocretin in young and old f344 rats. | hypocretins (hcrt-1 and hcrt-2), also known as orexins, are neuropeptides localized in neurons surrounding the perifornical region of the posterior hypothalamus. these neurons project to major arousal centers in the brain and are implicated in regulating wakefulness. in young rats and monkeys, levels of hcrt-1 are highest at the end of the wake-active period and lowest toward the end of the sleep period. however, the effects of age on the diurnal rhythm of hcrt-1 are not known. | 2004 | 15453542 |
| stereological analysis of the hypothalamic hypocretin/orexin neurons in an animal model of depression. | affective disorders often occur in combination with disrupted sleep-wake cycles and abnormal fluctuations in hypothalamic neurotransmitters. hypocretin (orexin) is a hypothalamic neuropeptide linked to narcolepsy, a sleep-related disorder characterized by profound disturbances in the normal sleeping pattern and variable degrees of depression. wistar-kyoto (wky) rats exhibit depressive characteristics and patterns of sleep disruption similar to that observed in depressed human patients. in this s ... | 2004 | 15464197 |
| acute wake-promoting actions of jnj-5207852, a novel, diamine-based h3 antagonist. | 1 1-[4-(3-piperidin-1-yl-propoxy)-benzyl]-piperidine (jnj-5207852) is a novel, non-imidazole histamine h3 receptor antagonist, with high affinity at the rat (pki=8.9) and human (pki=9.24) h3 receptor. jnj-5207852 is selective for the h3 receptor, with negligible binding to other receptors, transporters and ion channels at 1 microm. 2 jnj-5207852 readily penetrates the brain tissue after subcutaneous (s.c.) administration, as determined by ex vivo autoradiography (ed50 of 0.13 mg kg(-1) in mice). ... | 2004 | 15466448 |
| rhythms of ghrelin, leptin, and sleep in rats: effects of the normal diurnal cycle, restricted feeding, and sleep deprivation. | to determine the relationships among plasma ghrelin and leptin concentrations and hypothalamic ghrelin contents, and sleep, cortical brain temperature (tcrt), and feeding, we determined these parameters in rats in three experimental conditions: in free-feeding rats with normal diurnal rhythms, in rats with feeding restricted to the 12-h light period (rf), and in rats subjected to 5-h of sleep deprivation (sd) at the beginning of the light cycle. plasma ghrelin and leptin displayed diurnal rhythm ... | 2004 | 15475503 |
| reciprocal connections between subdivisions of the dorsal raphe and the nuclear core of the locus coeruleus in the rat. | the interconnection between two brainstem monoaminergic nuclei, the dorsal raphe (dr) and the locus coeruleus (lc), was analyzed in the rat using retrograde tracing and immunocytochemistry. gold-conjugated and inactivated wheatgerm agglutinin-horseradish peroxidase (wga-apo-hrp-gold) was injected into subdivisions of the dr or rostro-caudal levels of the nuclear core of the lc, and labeled lc or dr neurons were identified by dopamine-beta-hydroxylase (dbh) or 5-hydroxytryptamine (5-ht) immunosta ... | 2004 | 15476697 |
| in vivo trafficking and targeting of n-cadherin to nascent presynaptic terminals. | n-cadherin is a prominent component of developing and mature synapses, yet very little is known about its trafficking within neurons. to investigate n-cadherin dynamics in developing axons, we used in vivo two-photon time-lapse microscopy of n-cadherin--green fluorescent protein (ncad-gfp), which was expressed in rohon-beard neurons of the embryonic zebrafish spinal cord. ncad-gfp was present as either stable accumulations or highly mobile transport packets. the mobile transport packets were of ... | 2004 | 15483121 |
| cortical and pontine variations occurring in the voltammetric no signal throughout the sleep-wake cycle in the rat. | voltammetric measurements of nitric oxide (no) were performed either in the frontal cortex (cx) or in the nucleus raphe dorsalis (nrd) of rats equipped for polygraphic recordings. in the frontal cortex, the 650 mv signal related to no exhibited its highest height during the waking state (w) and decreased slightly during slow-wave sleep (sws) and even more during paradoxical sleep (ps). in the nrd, opposite variations were observed, i.e. the signal tended towards an increase during sws and raised ... | 2004 | 15493556 |
| gabaergic neurons with alpha2-adrenergic receptors in basal forebrain and preoptic area express c-fos during sleep. | the basal forebrain (bf) contains cholinergic neurons that stimulate cortical activation during waking. in addition, both the bf and adjacent preoptic area (poa) contain neurons that promote sleep. we examined c-fos expression in cholinergic and gabaergic neurons in the bf and poa to determine whether they are differentially active following sleep deprivation versus recovery and whether the gabaergic neurons are active during sleep. whereas the numbers of c-fos+ cells and proportions of c-fos+ c ... | 2004 | 15541901 |
| indirect projections from the suprachiasmatic nucleus to major arousal-promoting cell groups in rat: implications for the circadian control of behavioural state. | the circadian clock housed in the suprachiasmatic nucleus (scn) controls various circadian rhythms including daily sleep-wake cycles. using dual tract-tracing, we recently showed that the medial preoptic area (mpa), subparaventricular zone (spvz) and dorsomedial hypothalamic nucleus (dmh) are well positioned to relay scn output to two key sleep-promoting nuclei, namely, the ventrolateral and median preoptic nuclei. the present study examined the possibility that these three nuclei may link the s ... | 2005 | 15561433 |
| active medullary control of atonia in week-old rats. | muscle atonia is a central feature of adult rem sleep which has recently been demonstrated to be a component of sleep in rats as young as 2 days of age (p2). the neural generation of atonia, which depends on mesopontine and medullary structures, is not fully understood in adults and has never been described in infants. in the present experiments we used electrical stimulation in decerebrated pups to identify an inhibitory area within the medial medulla of p7-10 rats. muscle tone inhibition was c ... | 2005 | 15561443 |
| reverberation, storage, and postsynaptic propagation of memories during sleep. | in mammals and birds, long episodes of nondreaming sleep ("slow-wave" sleep, sw) are followed by short episodes of dreaming sleep ("rapid-eye-movement" sleep, rem). both sw and rem sleep have been shown to be important for the consolidation of newly acquired memories, but the underlying mechanisms remain elusive. here we review electrophysiological and molecular data suggesting that sw and rem sleep play distinct and complementary roles on memory consolidation: while postacquisition neuronal rev ... | 2004 | 15576886 |
| common scale-invariant patterns of sleep-wake transitions across mammalian species. | although mammals of different species have different sleep patterns, brief sleep-wake transitions commonly are observed across species and appear to occur randomly throughout the sleeping period. the dynamical patterns and functions of these brief awakenings from sleep are not well understood, and they often are viewed as disruptions (random or pathologic) of the sleep process. in this article, we hypothesize that brief awakenings from sleep may reflect aspects of the endogenous sleep control me ... | 2004 | 15583127 |
| effects of lesions of the histaminergic tuberomammillary nucleus on spontaneous sleep in rats. | extensive evidence suggests that histaminergic neurons promote wakefulness. histaminergic neurons are found exclusively in the tuberomammillary nucleus (tmn), and electrolytic lesions of the posterior hypothalamus, where the tmn resides, produce intense hypersomnolence. however, electrolytic lesions disrupt fibers of passage, and the effects of fiber-sparing, cell-specific tmn lesions on sleep and wakefulness are unknown. hence, we placed cell-specific lesions in the tmn to determine its role in ... | 2004 | 15586780 |
| neurotoxic lesions of phasic pontine-wave generator cells impair retention of 2-way active avoidance memory. | the aim of this study was to test the hypothesis that the activation of pontine (p)-wave generator is critical for the posttraining rapid eye movement (rem) sleep-dependent memory processing. | 2004 | 15586781 |
| global forebrain dynamics predict rat behavioral states and their transitions. | the wake-sleep cycle, a spontaneous succession of global brain states that correspond to major overt behaviors, occurs in all higher vertebrates. the transitions between these states, at once rapid and drastic, remain poorly understood. here, intracranial local field potentials (lfps) recorded in the cortex, hippocampus, striatum, and thalamus were used to characterize the neurophysiological correlates of the rat wake-sleep cycle. by way of a new method for the objective classification and quant ... | 2004 | 15590930 |
| methyl parathion increases neuronal activities in the rat locus coeruleus. | exposure to organophosphate insecticides induces undesirable behavioral changes in humans, including anxiety and irritability, depression, cognitive disturbances and sleep disorders. little information currently exists concerning the neural mechanisms underlying such behavioral changes. the brain stem locus coeruleus (lc) could be a mediator of organophosphate insecticide-induced behavioral toxicities since it contains high levels of acetylcholinesterase and is involved in the regulation of the ... | 2004 | 15591769 |
| altered setting of the pituitary-thyroid ensemble in hypocretin-deficient narcoleptic men. | narcolepsy is a sleep disorder caused by disruption of hypocretin (orexin) neurotransmission. injection of hypocretin-1 acutely suppresses trh and tsh release in rats. in contrast, subchronic administration does not appear to affect the hypothalamo-pituitary-thyroid ensemble in animals. we explored (in 7 patients and 7 controls) whether hypocretin deficiency impacts circulating tsh levels and circadian timing of tsh release in narcoleptic humans. plasma tsh concentration profiles (blood samples ... | 2004 | 15625087 |
| serotonin inputs to laryngeal constrictor motoneurons in the rat. | the objective was to demonstrate close appositions between serotonin-immunoreactive boutons and laryngeal constrictor (lcon) motoneurons in sprague-dawley rats. | 2005 | 15630377 |
| opposite effects of noradrenaline and acetylcholine upon hypocretin/orexin versus melanin concentrating hormone neurons in rat hypothalamic slices. | hypocretin/orexin (hcrt/orx) and melanin concentrating hormone (mch) are peptides contained in overlapping cell groups of the lateral hypothalamus and commonly involved in regulating sleep-wake states and energy balance, though likely in different ways. to see if these neurons are similarly or differentially modulated by neurotransmitters of the major brainstem arousal systems, the effects of noradrenaline (na) and carbachol, a cholinergic agonist, were examined on identified hcrt/orx and mch ne ... | 2005 | 15652980 |
| the wake-promoting peptide orexin-b inhibits glutamatergic transmission to dorsal raphe nucleus serotonin neurons through retrograde endocannabinoid signaling. | the wake-promoting neuropeptides orexins (hypocretins) play a crucial role in controlling neuronal excitability and synaptic transmission in the cns. in this study, using whole-cell patch-clamp recordings in an acute dorsal raphe nucleus (drn) slice preparation, we report that orexin b (orx-b) depresses the evoked glutamate-mediated synaptic currents in drn 5-ht neurons. the orx-b-induced depression is accompanied by an increase in the paired-pulse ratio and the coefficient of variance, suggesti ... | 2005 | 15673670 |
| effects of kava-kava extract on the sleep-wake cycle in sleep-disturbed rats. | kava-kava extract may be useful as an herbal medicine for treatment of insomnia and anxiety. | 2005 | 15700178 |
| differences in activity of cytochrome c oxidase in brain between sleep and wakefulness. | increased mrna level of subunit 1 cytochrome c oxidase (coxi) during wakefulness and after short-term sleep deprivation has been described in brain. we hypothesized that this might contribute to increased activity of cytochrome oxidase (cox) enzyme during wakefulness, as part of the mechanisms to provide sufficient amounts of adenosine triphosphate to meet increased neuronal energy demands. | 2005 | 15700717 |
| assessment of modafinil on attentional processes in a five-choice serial reaction time test in the rat. | it is well known that modafinil is an effective wake-promoting agent, but there is growing evidence to suggest that modafinil may also enhance some aspects of cognition. in man, modafinil has been shown to enhance vigilance in sleep-deprived and/or narcoleptic subjects and also to improve executive-type functioning (predominantly inhibitory response control processes) across a variety of human patient population groups. preclinically, a delay-dependent improvement has been reported with modafini ... | 2005 | 15728436 |
| ozone-induced paradoxical sleep decrease is related to diminished acetylcholine levels in the medial preoptic area in rats. | ozone (o3) produces significant effects on sleep, characterized specially by a decrease in paradoxical sleep (ps) and increase in slow-wave sleep (sws), which in turn represent a sleep-wake cycle disruption. on the other hand, neuronal activity recorded in the cholinoceptive hypothalamic medial preoptic area (mpo) has been involved in the regulation of sleep. however, there is no direct evidence on the role that acetylcholine (ach) release in the mpo plays in the sleep-wake cycle. in order to st ... | 2005 | 15733536 |
| fos expression in the suprachiasmatic nucleus in rats following high altitude exposure. | disturbances of circadian rhythms occur at high altitude. we examined the suprachiasmatic nucleus (scn), considered to be the biological clock in mammals that regulates circadian rhythmicity, in adult rats following an exposure to simulated high altitude. | 2005 | 15742827 |
| sleep-related brain activation does not increase the permeability of the blood-brain barrier to glucose. | we compared blood-brain barrier (bbb) permeability to glucose between quiet wakefulness and rapid-eye-movement (rem) sleep to assess whether changes in bbb permeability play a role in coupling glucose supply to the physiologic metabolic needs of the brain. male sprague-dawley rats were prepared with electrodes for wake-sleep state scoring and with arterial and venous catheters. using the single-pass, dual-label indicator method, unidirectional glucose extraction by the brain and cerebral blood f ... | 2005 | 15758946 |
| hearing in laboratory animals: strain differences and nonauditory effects of noise. | hearing in laboratory animals is a topic that traditionally has been the domain of the auditory researcher. however, hearing loss and exposure to various environmental sounds can lead to changes in multiple organ systems, making what laboratory animals hear of consequence for researchers beyond those solely interested in hearing. for example, several inbred mouse strains commonly used in biomedical research (e.g., c57bl/6, dba/2, and balb/c) experience a genetically determined, progressive heari ... | 2005 | 15766204 |
| orexin-a projections to the caudal medulla and orexin-induced c-fos expression, food intake, and autonomic function. | orexin-expressing neurons in the hypothalamus project throughout the neuraxis and are involved in regulation of the sleep/wake cycle, food intake, and autonomic functions. here we specifically analyze the anatomical organization of orexin projections to the dorsal vagal complex (dvc) and raphe pallidus and effects on ingestive behavior and autonomic functions of local orexin-a administration in nonanesthetized rats. retrograde tracing experiments revealed that as many as 20% of hypothalamic orex ... | 2005 | 15776447 |
| sleep-related vagotonic effect of zolpidem in rats. | zolpidem is a relatively new nonbenzodiazepine sedative-hypnotic. the effects of zolpidem on autonomic functions remain unclear. | 2005 | 15778879 |
| rem sleep: a sensitive index of fear conditioning in rats. | to examine the influence of conditioned fear stimuli on sleep-wake states, we recorded sleep in sprague-dawley rats after exposure to tones previously paired with footshock. after habituation to a recording chamber and the recording procedure, a baseline sleep recording was obtained the next day. one day later, experimental animals were exposed to shock training designed to induce conditioned fear (fc), consisting of five tone-footshock pairings. the 5-s tones (conditioned stimuli; cs) co-termin ... | 2005 | 15787712 |
| the wake-promoting hypocretin/orexin neurons change their response to noradrenaline after sleep deprivation. | sleep deprivation is accompanied by the progressive development of an irresistible need to sleep, a phenomenon whose mechanism has remained elusive. here, we identified for the first time a reflection of that phenomenon in vitro by showing that, after a short 2 h period of total sleep deprivation, the action of noradrenaline on the wake-promoting hypocretin/orexin neurons changes from an excitation to an inhibition. we propose that such a conspicuous modification of responsiveness should contrib ... | 2005 | 15843615 |
| cholinergic basal forebrain neurons burst with theta during waking and paradoxical sleep. | it is known that acetylcholine can stimulate activation and promote plasticity in the cerebral cortex, yet it is not known how the cholinergic basal forebrain neurons, which release acetylcholine in the cortex, discharge in relation to natural cortical activity and sleep-wake states. by recording basal forebrain units in association with electroencephalographic activity across the sleep-wake cycle and labeling individual neurons with neurobiotin for immunohistochemical identification, we show fo ... | 2005 | 15858062 |
| persistence of sleep-temperature coupling after suprachiasmatic nuclei lesions in rats. | the suprachiasmatic nucleus (scn) regulates the circadian rhythms of body temperature (t(b)) and vigilance states in mammals. we studied rats in which circadian rhythmicity was abolished after scn lesions (scnx rats) to investigate the association between the ultradian rhythms of sleep-wake states and brain temperature (t(br)), which are exposed after lesions. ultradian rhythms of t(br) (mean period: 3.6 h) and sleep were closely associated in scnx rats. within each ultradian cycle, nonrapid eye ... | 2005 | 15860650 |
| tetrodotoxin inactivation of pontine regions: influence on sleep-wake states. | studies using various methodologies have implicated n. reticularis pontis oralis (rpo) and n. subcoeruleus (subc) in the generation of rapid eye movement sleep (rem). in rats, electrolytic lesions in these regions may give rise to the phenomenon of rem without atonia (rem-a), in which the electrophysiological features of rem are normal except that atonia is absent and elaborate behaviors may be exhibited. however, electrolytic lesions damage both cell bodies and fibers of passage, and the neural ... | 2005 | 15862788 |
| sleep homeostasis in rats assessed by a long-term intermittent paradoxical sleep deprivation protocol. | numerous studies have evaluated the sleep homeostasis of rats after short- or long-periods of sleep deprivation, but none has assessed the effects of prolonged sleep restriction on the rat's sleep pattern. the purpose of the present study, therefore, was to evaluate the sleep homeostasis of rats under a protocol of chronic sleep restriction. male wistar rats were implanted with electrodes for eeg and emg recordings. using the single platform method, the animals were submitted to 18 h of sleep re ... | 2005 | 15863232 |
| locus ceruleus control of slow-wave homeostasis. | sleep intensity is regulated by the duration of previous wakefulness, suggesting that waking results in the progressive accumulation of sleep need (borbely and achermann, 2000). in mammals, sleep intensity is reflected by slow-wave activity (swa) in the nonrapid eye movement (nrem) sleep electroencephalogram, which increases in proportion to the time spent awake. however, the mechanisms responsible for the increase of nrem swa after wakefulness remain unclear. according to a recent hypothesis (t ... | 2005 | 15872097 |
| pontine-wave generator activation-dependent memory processing of avoidance learning involves the dorsal hippocampus in the rat. | the aim of this study was to test the hypothesis that the dorsal hippocampus plays a critical role in pontine-wave (p-wave) generator activation-dependent memory processing of two-way active avoidance (twaa) learning. to achieve this objective, rats were given small bilateral lesions in the ca1, dentate gyrus (dg), or ca3 region of the dorsal hippocampus by microinjecting ibotenic acid. after recovery, lesioned and sham-lesioned rats were trained on a twaa learning paradigm, allowed a 6-hr perio ... | 2005 | 15880522 |
| local functional state differences between rat cortical columns. | surface evoked potentials (seps) during auditory clicks and whisker twitches are usually larger during quiet sleep (qs) over waking and rem sleep. however, sep amplitudes from single trials fluctuate periodically between high and low values regardless of sleep-wake cycle. to test the hypothesis that state-independent fluctuations represent local functional sleep-like states of individual cortical columns, we examined single trial sep amplitudes from multiple cortical locations across sleep-wake ... | 2005 | 15882842 |
| a visual aid for computer-based analysis of sleep-wake state in rats. | computer-based sleep scoring systems are often calibrated by reference to a conventional visual analysis of electroencephalographic (eeg) and electromyographic (emg) traces. however, these types of data place high demands on digital storage capacity which may limit the duration or feasibility of some studies. the present paper describes an approach to visual analysis that involves reconstruction of a waveform (termed a "pseudopolygram" (ppg)) from conditioned data derived from the eeg and emg. t ... | 2005 | 15885800 |
| opposite effects of sleep rebound on orexin ox1 and ox2 receptor expression in rat brain. | orexins (hypocretins) have been implicated in the regulation of the normal sleep-wake cycle, in sensorimotor programming, and in other homeostatic and neuroregulatory processes. the present study examined the effects of sleep deprivation (sd) and sleep recovery on the expression of orexin 1 receptors (ox1r) and orexin 2 receptors (ox2r) throughout the brain. rats were sacrificed either immediately after 96 h of sleep deprivation (sd group) or after sd followed by 24 h of sleep recovery (rebound ... | 2005 | 15893599 |
| il-6 and its circadian secretion in humans. | interleukin-6 (il-6) is a pleiotropic cytokine produced by numerous types of immune and nonimmune cells and is involved in many pathophysiologic mechanisms in humans. many studies suggest that il-6 is a putative 'sleep factor' and its circadian secretion correlates with sleep/sleepiness. il-6 is elevated in disorders of excessive daytime sleepiness such as narcolepsy and obstructive sleep apnea. it correlates positively with body mass index and may be a mediator of sleepiness in obesity. also th ... | 2005 | 15905620 |
| behavioural effects of dimethyl sulfoxide (dmso): changes in sleep architecture in rats. | dimethyl sulfoxide (dmso) is an efficient solvent for water-insoluble compounds, widely used in biological studies and as a vehicle for drug therapy, but few data on its neurotoxic or behavioural effects is available. the aim of this work is to explore dmso's effects upon sleep/wake states. twenty male rats were sterotaxically prepared for polysomnography. four concentrations of dmso (5%, 10%, 15%, and 20%, in saline) were examined. dmso or saline were administered intraperitoneally at the begin ... | 2005 | 15917147 |
| selective stimulation of orexin receptor type 2 promotes wakefulness in freely behaving rats. | orexins a and b are a pair of neuropeptides implicated in the regulation of feeding and arousal behavior mediated through two orexin receptors type 1 and type 2. we have determined the arousal effects of newly developed selective orexin receptor type 2 agonist, [ala11]orexin-b, on the sleep-wake cycle in rats. the effects of third ventricle intracerebroventricular (icv) infusion of the novel orexin receptor type 2 selective agonist, [ala11]orexin-b, on the sleep-wake cycle were investigated. icv ... | 2005 | 15919057 |
| the effects of intracerebroventricular application of 8-br-cgmp and ly-83,583, a guanylyl cyclase inhibitor, on sleep-wake activity in rats. | cyclic gmp is the second messenger that mediates most of the neuronal effects of nitric oxide (no). several lines of evidence suggest that no-ergic mechanisms play an integral role in the regulation of vigilance. in the present study, we tested the effects of the activation of cgmp-receptive mechanisms and the inhibitor of guanylyl cyclase (gc), ly-83,583, on sleep in rats. rats were injected intracerebroventricularly (icv) with 0.16, 4, 100, and 500 microg or 2.5 mg 8-br-cgmp, a membrane-permea ... | 2005 | 15922313 |
| chloramphenicol decreases brain glucose utilization and modifies the sleep-wake cycle architecture in rats. | we studied the effects of chloramphenicol on brain glucose utilization and sleep-wake cycles in rat. after slightly anaesthetized animals were injected with [18f]fluoro-2-deoxy-d-glucose, we acquired time-concentration curves from three radiosensitive beta microprobes inserted into the right and left frontal cortices and the cerebellum, and applied a three-compartment model to calculate the cerebral metabolic rates for glucose. the sleep-wake cycle architecture was analysed in anaesthetic-free r ... | 2005 | 15935079 |
| changes in eeg activity and hypothalamic temperature as indices for non-rem sleep to rem sleep transitions. | a shift of physiological regulations from a homeostatic to a non-homeostatic modality characterizes the passage from non-nrem sleep (nrems) to rem sleep (rems). in the rat, an eeg index which allows the automatic scoring of transitions from nrems to rems has been proposed: the nrems to rems transition indicator value, niv [j.h. benington et al., sleep 17 (1994) 28-36]. however, such transitions are not always followed by a rems episode, but are often followed by an awakening. in the present stud ... | 2005 | 15936533 |
| urotensin ii modulates rapid eye movement sleep through activation of brainstem cholinergic neurons. | urotensin ii (uii) is a cyclic neuropeptide with strong vasoconstrictive activity in the peripheral vasculature. uii receptor mrna is also expressed in the cns, in particular in cholinergic neurons located in the mesopontine tegmental area, including the pedunculopontine tegmental (ppt) and lateral dorsal tegmental nuclei. this distribution suggests that the uii system is involved in functions regulated by acetylcholine, such as the sleep-wake cycle. here, we tested the hypothesis that uii influ ... | 2005 | 15944374 |
| the brain is a target organ after acute exposure to depleted uranium. | the health effects of depleted uranium (du) are mainly caused by its chemical toxicity. although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. in this paper, the central effects of acute exposure to du were studied in relation to health parameters and the sleep-wake cycle of adult rats. animals were injected intraperitoneally with 144+/-10 microg du kg-1 as nitrate. three days after injection, the amounts of uranium in the kidneys represented 2.6 ... | 2005 | 15951092 |
| differential effect of sleep-wake states on lingual and dorsal neck muscle activity in rats. | postural tone is reduced during slow-wave sleep (sws) and absent during rapid eye movement sleep (rems). in obstructive sleep apnea subjects, upper airway dilating muscles, including those of the tongue, show a similar pattern; this contributes to sleep-related airway obstructions. however, in healthy subjects, state-dependent changes in the activity of pharyngeal muscles are variable. in seven chronically instrumented sprague-dawley rats, an animal model used to study sleep and sleep-disordered ... | 2005 | 15964252 |
| acute administration of the novel serotonin and noradrenaline reuptake inhibitor, s33005, markedly modifies sleep-wake cycle architecture in the rat. | the interrelationship between depressive states and sleep-wake cycle architecture is characterised by a decreased latency to the first paradoxical sleep (ps) episode, together with an enhancement of ps during the first part of the night. conversely, slow-wave sleep (sws) is decreased and intermittent awakenings increased. notably, antidepressant treatment is generally associated with a diminution of ps. | 2005 | 15983796 |
| hypocretin/orexin selectively increases dopamine efflux within the prefrontal cortex: involvement of the ventral tegmental area. | hypocretins (hcrts) modulate a variety of behavioral and physiological processes, in part via interactions with multiple ascending modulatory systems. further, hcrt efferents from the lateral hypothalamus innervate midbrain dopamine (da) nuclei, and da cell bodies express hcrt receptors. combined, these observations suggest that hcrt may influence behavioral state and/or state-dependent processes via modulation of da neurotransmission. the current studies used in vivo microdialysis in the unanes ... | 2006 | 15988471 |
| antagonism of corticotropin-releasing hormone alters serotonergic-induced changes in brain temperature, but not sleep, of rats. | serotonin is involved in many physiological processes, including the regulation of sleep and body temperature. administration into rats of low doses (25, 50 mg/kg) of the 5-ht precursor l-5-hydroxytryptophan (5-htp) at the beginning of the dark period of the 12:12-h light-dark cycle initially increases wakefulness. higher doses (75, 100 mg/kg) increase nonrapid eye movement (nrem) sleep. the initial enhancement of wakefulness after low-dose 5-htp administration may be a direct action of 5-ht in ... | 2005 | 15994374 |
| vasculature deprivation--induced osteonecrosis of the rat femoral head as a model for therapeutic trials. | experimental osteonecrosis: the authors' experience with experimentally produced femoral capital osteonecrosis in rats is reviewed: incising the periosteum at the base of the neck of the femur and cutting the ligamentum teres leads to coagulation necrosis of the epiphysis. the necrotic debris is substituted by fibrous tissue concomitantly with resorption of the dead soft and hard tissues by macrophages and osteoclasts, respectively. progressively, the formerly necrotic epiphysis is repopulated b ... | 2005 | 15996271 |
| enriched but not depleted uranium affects central nervous system in long-term exposed rat. | uranium is well known to induce chemical toxicity in kidneys, but several other target organs, such as central nervous system, could be also affected. thus in the present study, the effects on sleep-wake cycle and behavior were studied after chronic oral exposure to enriched or depleted uranium. rats exposed to 4% enriched uranium for 1.5 months through drinking water, accumulated twice as much uranium in some key areas such as the hippocampus, hypothalamus and adrenals than did control rats. th ... | 2005 | 15996736 |
| wake-promoting actions of medial basal forebrain beta2 receptor stimulation. | the locus coeruleus-noradrenergic system exerts an activating influence on forebrain neuronal and behavioral activity states, in part, through the actions of noradrenergic beta receptors located within the medial septal (ms) and medial preoptic (mpoa) areas. the current study examined the extent to which beta2 receptors located within these medial basal forebrain regions modulate behavioral state. in this study, the sleep-wake effects of microinfusion of the beta2 agonist, clenbuterol, into the ... | 2005 | 15998195 |
| transient alterations in neuronal and behavioral activity following bensultap and fipronil treatment in rats. | in the present multilevel study, neuromodulatory effect of two insecticides, bensultap and fipronil were investigated in rats. although the new generation of insecticides shows greater affinity to invertebrate as compared to mammalian receptors, toxic effect of these compounds in vertebrates cannot be excluded. the aim of the study was to follow the course of neuronal changes in rats for 1 week after a high-dose insecticide exposure. alterations in synaptic excitability, in sleep-wake pattern an ... | 2005 | 16009481 |
| 7-12 hz cortical oscillations: behavioral context and dynamics of prefrontal neuronal ensembles. | 7-12 hz oscillations, characterized by spindle-like high-voltage rhythmic spike components, appear in quiet immobile states of rats. however, it remains unclear what their relationships with preceding behavioral activities are and how prefrontal neuronal dynamics during these oscillations is. in the present study, we first determined the relationship of 7-12 hz oscillations with the wake-sleep cycle and preceding behavioral activities in several normal rat strains by recording electroencephalogr ... | 2005 | 16019153 |
| role of endogenous serotonin in modulating genioglossus muscle activity in awake and sleeping rats. | exogenous serotonin at the hypoglossal motor nucleus (hmn) stimulates genioglossus (gg) muscle activity. however, whether endogenous serotonin contributes to gg activation across natural sleep-wake states has not been determined, but is relevant given that serotonergic neurons have decreased activity in sleep and project to pharyngeal motoneurons. | 2005 | 16020803 |
| chronic ethanol intake alters circadian period-responses to brief light pulses in rats. | although chronic alcohol intake is associated with widespread disruptions of sleep-wake cycles and other daily biological rhythms in both human alcoholics and experimental animals, the extent to which the chronobiological effects of alcohol are mediated by effects on the underlying circadian pacemaker remains unknown. nevertheless, recent studies indicate that both adult and perinatal ethanol treatments may alter the free-running period and photic responsiveness of the circadian pacemaker. the p ... | 2005 | 16021840 |
| effects of selective neuronal nitric oxide synthase inhibition on sleep and wakefulness in the rat. | the role played by the unconventional messenger nitric oxide (no) upon the sleep-wake cycle remains controversial. evidence suggests a positive role of no on slow wave sleep (sws) and paradoxical sleep (ps) regulation, favoring sleep. however, other studies have found a role of no upon wakefulness and alertness, inhibiting sleep. divergences have been explained in part because of the use of different inhibitors of nitric oxide synthases (nos). the aim of this study is to analyse the effects of a ... | 2006 | 16023276 |
| the endogenous somnogen adenosine excites a subset of sleep-promoting neurons via a2a receptors in the ventrolateral preoptic nucleus. | recent research has shown that neurons in the ventrolateral preoptic nucleus are crucial for sleep by inhibiting wake-promoting systems, but the process that triggers their activation at sleep onset remains to be established. since evidence indicates that sleep induced by adenosine, an endogenous sleep-promoting substance, requires activation of brain a(2a) receptors, we examined the hypothesis that adenosine could activate ventrolateral preoptic nucleus sleep neurons via a(2a) adenosine recepto ... | 2005 | 16039802 |
| variations in extracellular levels of dopamine, noradrenaline, glutamate, and aspartate across the sleep--wake cycle in the medial prefrontal cortex and nucleus accumbens of freely moving rats. | we used intracerebral microdialysis coupled with electrophysiologic recordings to determine relative changes in the concentrations of several neurotransmitters in the medial prefrontal cortex and nucleus accumbens of freely moving rats during waking, slow-wave sleep, and rapid eye movement (rem) sleep. the concentrations of noradrenaline, dopamine, glutamate, and aspartate in 2-min dialysate samples were analyzed by capillary electrophoresis combined with laser-induced fluorescence detection. ch ... | 2005 | 16041801 |
| [orexin, sleep and appetite regulation: a review]. | since 1998, two research groups independently reported the discovery of two novel hypothalamic neuropeptides, called hypocretin-1 and hypocretin-2, respectively many studies have been carried out about their possible functions. one group named these new peptides orexins (a and b) after the greek word for appetite, since they found that central administration of orexins potently increased food intake in rats. however hypocretins/ orexins are involved in various hypothalamic mechanisms, such as en ... | 2005 | 16048028 |
| effects of valerian extract on the sleep-wake cycle in sleep-disturbed rats. | the present study was performed to investigate the effects of valerian extract on the sleep-wake cycle using sleep-disturbed model rats. a significant shortening in sleep latency was observed with valerian extract at doses of 1000 and 3000 mg/kg. on the other hand, valerian extract had no significant effects on total times of wakefulness, non-rapid eye movement (non-rem) sleep, or rem sleep, even at a dose of 3000 mg/kg. valerian extract at doses of 1000 and 3000 mg/kg showed a significant incre ... | 2005 | 16049561 |
| sleep-related changes in cardiovascular neural regulation in spontaneously hypertensive rats. | sleep has significant effects on cardiovascular neural regulation. the aim of this study is to explore the possible change in sympathetic vasomotor activity and baroreflex sensitivity associated with spontaneous hypertension during each stage of the sleep-wake cycle. | 2005 | 16061742 |
| characterization of the spontaneous and gripping-induced immobility episodes on taiep rats. | in 1989, we described a new autosomic-recessive myelin-mutant rat that develops a progressive motor syndrome characterized by tremor, ataxia, immobility episodes (ies), epilepsy, and paralysis. taiep is the acronym of these symptoms. the rat developed a hypomyelination, followed by demyelination. at an age of 7-8 months, taiep rats developed ies, characterized electroencephalographically by rem sleep-like cortical activity. in our study, we analyzed the ontogeny of gripping-induced ies between 5 ... | 2005 | 16088950 |
| changes in sleep-wake cycle after chronic exposure to uranium in rats. | uranium is a heavy metal known to induce toxicity in kidneys. it is also known to enter the central nervous system, thus inducing neurophysiological effects, after exposure to relatively high concentrations. the effect of chronic uranium exposure (40 mg l(-1) in drinking water, for 90 days) on electroencephalographic architecture has been studied on freely moving rats using a telemetry technique. the main effects of uranium on the sleep-wake cycle were an increase in rapid eye movement sleep (re ... | 2005 | 16099620 |
| effects on sleep of microdialysis of adenosine a1 and a2a receptor analogs into the lateral preoptic area of rats. | evidence suggests that adenosine (ad) is an endogenous sleep factor. the hypnogenic action of ad is mediated through its inhibitory a1 and excitatory a2a receptors. although ad is thought to be predominantly active in the wake-active region of the basal forebrain (bf), a hypnogenic action of ad has been demonstrated in several other brain areas, including the preoptic area. we hypothesized that in lateral preoptic area (lpoa), a region with an abundance of sleep-active neurons, ad acting via a1 ... | 2005 | 16109808 |
| potential role of inducible nitric oxide synthase in the sleep-wake states occurrence in old rats. | extensive evidences now suggest that an association between inducible nitric oxide synthase and oxidative stress takes place during aging. since the part played by inducible nitric oxide synthase in the sleep impairments associated with aging still remains unexplored, we compared its involvement in old rats (20-24 months) versus adult ones (3-5 months) using polygraphic, biochemical, voltammetric and immunohistochemical techniques. the experiments were conducted either in basal condition or afte ... | 2005 | 16112470 |
| extraocular muscle activity, rapid eye movements and the development of active and quiet sleep. | rapid eye movements (rems), traditionally measured using the electrooculogram (eog), help to characterize active sleep in adults. in early infancy, however, they are not clearly expressed. here we measured extraocular muscle activity in infant rats at 3 days of age (p3), p8 and p14-15 in order to assess the ontogeny of rems and their relationship with other forms of sleep-related phasic activity. we found that the causal relationship between extraocular muscle twitches and rems strengthened duri ... | 2005 | 16115214 |
| prenatal protein malnutrition induces a phase shift advance of the spontaneous locomotor rhythm and alters the rest/activity ratio in adult rats. | evidence is accumulating for significant structural and functional changes within the central nervous system (cns) following prenatal protein malnutrition. included among the structures that are likely to be affected are the suprachiasmatic nuclei (scn) involved in the regulation of locomotor activity, sleep-wake cycle, and drinking behavior. to determine the effects of prenatal protein malnutrition on the spontaneous activity rhythm, 24 h radiotelemetric measurements were recorded over an 8-day ... | 2005 | 16117184 |
| influence of long-term food restriction on sleep pattern in male rats. | the present purpose was to determine the effects of different schedules of long-term food restriction (fr) applied to rats from weaning to the 8th week. rats were distributed into fr and ad libitum groups at weaning and fed at 7 am, at 7 pm, and finally, restricted rats fed ad libitum. the restricted rats started with 6 g/day and the food was increased by 1 g per week until reaching 15 g/day by adulthood. the rats were implanted with electrodes to record electrocorticogram/eletromyogram signals. ... | 2005 | 16122716 |
| the physiological role of orexins. | orexins/hypocretins are recently discovered neuropeptides synthetized mainly by neurons located in the posterolateral hypothalamus. hypocretin-1 and -2 are the same peptides as orexin-a and orexin-b. orexin a is a 33 amino acid peptide with n-terminal pyroglutamyl residue and two intrachain disulphide bonds. orexin b is a linear peptide of 28 amino acids. these two peptides are potent agonists at both the orexin-1 (oxr1) and orexin-2 (oxr2) receptors. orexin-a is selective ligand for oxr1 and ox ... | 2005 | 16135995 |
| pattern of orexin expression and direct biological actions of orexin-a in rat testis. | orexins, hypothalamic neuropeptides initially involved in the control of food intake and sleep-wake cycle, have recently emerged as pleiotropic regulators of different biological systems, including the reproductive axis. besides central actions, peripheral expression and functions of orexins have been reported, and prepro-orexin and orexin type-1 receptor mrnas have been detected in the testis. however, the pattern of expression and biological actions of orexin in the male gonad remain mostly un ... | 2005 | 16141395 |
| retrograde study of hypocretin-1 (orexin-a) projections to subdivisions of the dorsal raphe nucleus in the rat. | a retrograde tracer, wga-apo-hrp-gold (wg), was injected into each subdivision of the dorsal raphe (dr) nucleus, and subsequent orexin-a immunostaining was performed for the tuberal region of the hypothalamus in order to investigate orexin projections to the dr. similar to previous studies, the majority of orexin-single-labeled neurons were observed at the dorsal half of the lateral hypothalamus (lh), the circle around the fornix, i.e., perifornical nucleus (pef), and the area dorsal to the forn ... | 2005 | 16153616 |
| gaba(a) receptors mediate orexin-a induced stimulation of food intake. | although the role of orexins in sleep/wake cycle and feeding behavior is well established, underlying mechanisms have not been fully understood. an attempt has been made to investigate the role of gaba(a) receptors and their benzodiazepine site on the orexin-a induced response to feeding. different groups of rats were food deprived overnight and next day injected intracerebroventricularly (icv) with vehicle (artificial csf; 5 microl/rat) or orexin-a (20-50 nm/rat) and the animals were given free ... | 2006 | 16168444 |
| state-dependent effects of light-dark cycle on somatosensory and visual cortex eeg in rats. | somatosensory (ssctx) and visual cortex (vctx) eeg were evaluated in rats under a 12:12-h light-dark (ld) cycle and under constant light (ll) or constant dark (dd) in each sleep or wake state. under ld conditions during light period, relative vctx eeg slow-wave activity (swa) was higher than that of the ssctx, whereas during dark period, relative vctx eeg swa was lower than in the ssctx. these effects were state specific, occurring only during non-rapid eye movement sleep (nrems). under ll condi ... | 2005 | 16183627 |
| dynamics of sleep-wake cyclicity in developing rats. | adult mammals cycle between periods of sleep and wakefulness. recent assessments of these cycles in humans and other mammals indicate that sleep bout durations exhibit an exponential distribution, whereas wake bout durations exhibit a power-law distribution. moreover, it was found that wake bout distributions, but not sleep bout distributions, exhibit scale invariance across mammals of different body sizes. here we test the generalizability of these findings by examining the distributions of sle ... | 2005 | 16192355 |
| donepezil restores gh secretion in old rats without affecting the sleep/wake cycle. | a chronic treatment with a cholinesterase inhibitor, donepezil (0.085 mg/kg/h for 30 days) increases significantly the number and amplitude of growth hormone (gh) pulses in 3- and 24-month-old rats without modifying nadir gh values. this treatment does not reduce age-related alterations in sleep/wake cycle but it increases immobility-related high-voltage spindles (hvs) in old animals. these data suggest that cholinergic mechanisms involved in age-related alterations in gh and sleep regulation ar ... | 2006 | 16199109 |
| antidepressants and rem sleep in wistar-kyoto and sprague-dawley rats. | compared to other rat strains, the wistar-kyoto rats show increased amount of rem sleep, one of the characteristic sleep changes observed in depressed patients. the aims of this study were firstly to validate a simple sleep stage discriminator and then compare the effect of antidepressants on suppression of rapid eye movement (rem) sleep in wistar-kyoto rats and an outbred rat strain (sprague-dawley). rats were implanted with telemetry transmitters with electroencephalogram/electromyogram electr ... | 2005 | 16223479 |
| gene expression in the rat brain during sleep deprivation and recovery sleep: an affymetrix genechip study. | previous studies have demonstrated that macromolecular synthesis in the brain is modulated in association with the occurrence of sleep and wakefulness. similarly, the spectral composition of electroencephalographic activity that occurs during sleep is dependent on the duration of prior wakefulness. since this homeostatic relationship between wake and sleep is highly conserved across mammalian species, genes that are truly involved in the electroencephalographic response to sleep deprivation migh ... | 2006 | 16257491 |
| histamine-immunoreactive neurons in the mouse and rat suprachiasmatic nucleus. | among the well-established roles of the neurotransmitter histamine (ha) is that as a regulator of the sleep-wake cycle, which early gained ha a reputation as a 'waking substance'. the tuberomammillary nucleus (tmn) of the posterior hypothalamus, which contains the sole source of neuronal ha in the brain, is reciprocally connected to the suprachiasmatic nucleus (scn) which, in turn, is best known as the pacemaker of circadian rhythms in mammals. we report ha-immunoreactive (-ir) neurons in the mo ... | 2005 | 16262638 |
| circadian regulation of sleep in mammals: role of the suprachiasmatic nucleus. | despite significant progress in elucidating the molecular basis for circadian oscillations, the neural mechanisms by which the circadian clock organizes daily rhythms of behavioral state in mammals remain poorly understood. the objective of this review is to critically evaluate a conceptual model that views sleep expression as the outcome of opponent processes-a circadian clock-dependent alerting process that opposes sleep during the daily wake period, and a homeostatic process by which sleep dr ... | 2005 | 16269313 |
| neonatal alcohol exposure permanently disrupts the circadian properties and photic entrainment of the activity rhythm in adult rats. | alcohol exposure during the period of rapid brain development produces structural damage in different brain regions, including the suprachiasmatic nucleus (scn), that may have permanent neurobehavioral consequences. thus, this study examined the long-term effects of neonatal alcohol exposure on circadian behavioral activity in adult rats. | 2005 | 16269914 |
| sleep deprivation-induced protein changes in basal forebrain: implications for synaptic plasticity. | the need to sleep is universal and lack of sleep often results in decreases in alertness and cognitive function. data suggest that sleep-related mechanisms and deficits resulting from loss of sleep are associated anatomically with the basal forebrain. long-term effects of sleep deprivation, those lasting a day or more, likely require transcriptional changes leading to changes in protein synthesis, whereas short-term effects may be mediated by rapid changes in the functional status of proteins. t ... | 2005 | 16273548 |
| increased serotonin receptor availability in human sleep: evidence from an [18f]mppf pet study in narcolepsy. | data from animal studies suggest that serotonin release promotes wakefulness and suppresses rem sleep, but there are dangers in extrapolating these findings to humans. binding of the radioligand [18f]mppf to 5ht1a receptors is sensitive to levels of endogenous serotonin. in this study, we aimed to demonstrate changes in serotonin receptor availability in the human brain in wakefulness and sleep using [18f]mppf and positron emission tomography. 14 subjects with narcolepsy cataplexy underwent [18f ... | 2006 | 16275016 |