Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| acute effects of melatonin on spontaneous and picrotoxin-evoked sleep-wake behaviour in the rat. | various studies indicate that exogenous melatonin has hypnotic properties in humans, which may be mediated by its influence on the circadian timing system or direct sleep-promoting actions, e.g. through a modulation of gabaergic transmission. the aim of the present placebo-controlled study was to examine the effects of melatonin on sleep in rats and the contribution of gamma-aminobutyric acid (gaba)a receptors. sleep-wake behaviour was assessed in nine rats after intraperitoneal (i.p.) administr ... | 2001 | 11696074 |
| fluctuation of extracellular hypocretin-1 (orexin a) levels in the rat in relation to the light-dark cycle and sleep-wake activities. | hypocretins/orexins are neuropeptides implicated in sleep regulation and the sleep disorder narcolepsy. in order to examine how hypocretin activity fluctuates across 24 h with respect to the sleep-wake cycle, we measured changes in extracellular hypocretin-1 levels in the lateral hypothalamus and medial thalamus of freely moving rats with simultaneous sleep recordings. hypocretin levels exhibited a robust diurnal fluctuation; levels slowly increased during the dark period (active phase), and dec ... | 2001 | 11683899 |
| central and baroreflex control of heart rate during the wake-sleep cycle in rat. | spontaneous fluctuations in heart period (hp) and mean arterial pressure (map) make it possible to evaluate baroreceptor-heart rate reflex sensitivity (brs). 30-s sequences of hp and map beat-to-beat values were considered in the different wake-sleep states (wake, w; quiet sleep, qs; active sleep, as) in rats to assess whether 1) brs changes between states and 2) the different indexes supply consistent brs measures. brs indexes were calculated according to validated literature procedures as regr ... | 2001 | 11683478 |
| wake-promoting and sleep-suppressing actions of hypocretin (orexin): basal forebrain sites of action. | the hypocretins (orexins) are a newly identified peptide family comprised of two peptides, hypocretin-1 and hypocretin-2. recent observations suggest an involvement of these peptides in the regulation of behavioral state. for example, these peptides are found in a variety of brain regions associated with the regulation of forebrain neuronal and behavioral activity states. furthermore, when infused into the lateral ventricles in awake animals, hypocretin-1 elicits increased duration of waking bey ... | 2001 | 11682157 |
| excitation of the pedunculopontine tegmental nmda receptors induces wakefulness and cortical activation in the rat. | microinjection of the excitatory amino acid, l-glutamate into the brainstem pedunculo pontine tegmentum (ppt) has been shown to induce wakefulness, however, it has been unclear that receptors mediate this effect. the aim of this study was to test the hypothesis that in the ppt, l-glutamate induces cortical activation and wakefulness via activation of nmda receptors. to test this hypothesis, three sets of micro-injections into the ppt were carried out on two different groups of rats that were the ... | 2001 | 11599007 |
| developmental alcohol and circadian clock function. | studies in rats found that alcohol exposure during the early postnatal period, particularly during the brain-growth-spurt period, can result in cell loss in various brain regions and persistent behavioral impairments. some investigators have speculated that the body's internal clock, which is located in the suprachiasmatic nuclei (scn) in the brain, may also be affected by developmental alcohol exposure. for example, alcohol-induced damage to the scn cells and their function could result in dist ... | 2001 | 11584552 |
| circadian rhythms and sleep have additive effects on respiration in the rat. | 1. we tested two hypotheses: that respiration and metabolism are subject to circadian modulation in wakefulness, non-rapid-eye-movement (nrem) sleep and rapid-eye-movement (rem) sleep; and that the effects of sleep on breathing vary as a function of time of day. 2. electroencephalogram (eeg), neck electromyogram (emg) and abdominal body temperature (t(b)) were measured by telemetry in six male sprague-dawley rats. the eeg and emg were used to identify sleep-wake states. ventilation (v(i)) and me ... | 2001 | 11579171 |
| similar genetic mechanisms may underlie sleep-wake states in neonatal and adult rats. | genetic differences in the characteristics of sleep-wake states in adult animals offer a potential window for examining how the neonatal and adult behavioural states are related to one another. our recent finding that adult wistar-kyoto (wky) rats show pronounced genetic differences in sleep-wake patterns relative to the wistar (wis) control strain led us to investigate the relationship between these behavioural states in neonates and adults in a longitudinal study in these two strains of rats. ... | 2001 | 11568642 |
| the influence of subchronic administration of the neurosteroid allopregnanolone on sleep in the rat. | the endogenous neurosteroid allopregnanolone has recently been demonstrated to have somnogenic properties that are very similar to those of other agonistic modulators of gaba(a) receptors, especially of short-acting benzodiazepines. short-acting benzodiazepines are established to rapidly lose their hypnotic effect upon repeated administration. to investigate the tolerance potential of allopregnanolone, we assessed sleep-wake behavior in rats during subchronic treatment (once daily for five days) ... | 2001 | 11557171 |
| comparative effects of melatonin, zolpidem and diazepam on sleep, body temperature, blood pressure and heart rate measured by radiotelemetry in wistar rats. | the role of melatonin (mlt) in mediating the sleep-wake cycle has been previously suspected of indicating that this substance could be a candidate for a new generation of hypnotics. | 2001 | 11498719 |
| arousal effect of orexin a depends on activation of the histaminergic system. | orexin neurons are exclusively localized in the lateral hypothalamic area and project their fibers to the entire central nervous system, including the histaminergic tuberomammillary nucleus (tmn). dysfunction of the orexin system results in the sleep disorder narcolepsy, but the role of orexin in physiological sleep-wake regulation and the mechanisms involved remain to be elucidated. here we provide several lines of evidence that orexin a induces wakefulness by means of the tmn and histamine h(1 ... | 2001 | 11493714 |
| extracellular serotonin variations during vigilance states in the preoptic area of rats: a microdialysis study. | numerous studies have shown that serotonergic transmission decreases from waking (w) to slow wave sleep (sws) to paradoxical sleep (ps), suggesting an active role of serotonin (5-ht) in w but not in sleep. conversely, the inhibition of 5-ht activity produces insomnia. this insomnia can be reversed by injections of 5-hydroxytryptophan in the preoptic area (poa), suggesting that 5-ht is necessary in this cerebral structure for sleep. using microdialysis, we studied, 5-ht variations in the poa of r ... | 2001 | 11489253 |
| firing rates of hippocampal neurons are preserved during subsequent sleep episodes and modified by novel awake experience. | what determines the firing rate of cortical neurons in the absence of external sensory input or motor behavior, such as during sleep? here we report that, in a familiar environment, the discharge frequency of simultaneously recorded individual ca1 pyramidal neurons and the coactivation of cell pairs remain highly correlated across sleep-wake-sleep sequences. however, both measures were affected when new sets of neurons were activated in a novel environment. nevertheless, the grand mean firing ra ... | 2001 | 11470910 |
| orexins: effects on behavior and localisation of orexin receptor 2 messenger ribonucleic acid in the rat brainstem. | the orexins are neuropeptides originally reported to be involved in the stimulation of food intake. however, analysis of orexin immunoreactive fibres have revealed the densest innervation in brain sites involved in arousal and sleep-wake control, notably the noradrenergic locus coeruleus, an area that also expresses orexin receptor 1 (ox1r) messenger rna (mrna). we report here that, in the rat, a single intracerebroventricular injection of orexin a (1 and 3 nmol) or orexin b (3 nmol), during the ... | 2001 | 11430882 |
| contrasting effects of ibotenate lesions of the paraventricular nucleus and subparaventricular zone on sleep-wake cycle and temperature regulation. | the suprachiasmatic nucleus (scn), the circadian pacemaker for the brain, provides a massive projection to the subparaventricular zone (spz), but the role of the spz in circadian processes has received little attention. we examined the effects on circadian rhythms of sleep, body temperature, and activity in rats of restricted ibotenic acid lesions of the ventral or dorsal spz that spared the immediately adjacent paraventricular hypothalamic nucleus (pvh) and the scn. ventral spz lesions caused p ... | 2001 | 11425913 |
| the role of the central nervous system in nacl-sensitive hypertension in spontaneously hypertensive rats. | the central and peripheral nervous system is typically considered to be a short-term modifier of sympathetic nervous system activity, but several lines of evidence suggest that they contribute to chronic elevation of arterial pressure in at least some forms of hypertension. our studies focus on the mechanisms underlying nacl-sensitive hypertension in the spontaneously hypertensive rat (shr). when these rats are fed a high nacl diet, their arterial pressure rapidly increases and is maintained abo ... | 2001 | 11411751 |
| sleep is differently modulated by basal forebrain gaba(a) and gaba(b) receptors. | there is evidence that gaba plays a major role in sleep regulation. gaba(a) receptor agonists and different compounds interacting with the gaba(a) receptor complex, such as barbiturates and benzodiazepines, can interfere with the sleep/wake cycle. on the other hand, there is very little information about the possible role of gaba(b) receptors in sleep modulation. the nucleus basalis of meynert (nbm), a cholinergic area in the basal forebrain, plays a pivotal role in the modulation of sleep and w ... | 2001 | 11404291 |
| sleep and memory deficits in the rat produced by experimental infection with trypanosoma cruzi. | we investigated whether the infection with trypanosoma cruzi in rats could produce functional alterations of the central nervous system. the experimental group received an injection of 150,000 trypomastigotes / rat, whereas the control group received a saline injection. spontaneous alternation behavior (sab) tests and sleep-wake cycle recordings were obtained at the end of the parasitaemia. results showed that the infected animals had significant sleep impairments, as denoted by an increase in t ... | 2001 | 11403959 |
| rem sleep enhancement due to rhythmical auditory stimulation in the rat. | from a physiological viewpoint, rem sleep (rems) is a period during which homeostatic physiological regulations are impaired. in the rat, rems occurs in two forms respectively characterized by episodes separated by long intervals (single rems episodes) and by episodes which have short intervals and occur in sequences (rems clusters). since the partition of rems in the form of either single or clustered episodes may reveal how the rems drive and body homeostatic processes interact in the control ... | 2001 | 11399328 |
| sleep-wake and eeg effects following adenosine a1 agonism and antagonism: similarities and interactions with sleep-wake and eeg effects following a serotonin reuptake inhibitor in rats. | adenosine is currently being investigated as a possible mediator of a homeostatic sleep need. reports from different laboratories suggest that both adenosine a1 agonists and selective serotonin reuptake inhibitors (ssri) increase deep slow wave sleep (sws-2) after an interval. in this study, the sleep-wake effects of the adenosine a1 agonist n6-cyclopentyladenosine (cpa) and the ssri zimeldine are directly compared in the same animals. since the sws-2 increase following ssris may be secondary to ... | 1998 | 11382868 |
| pontine injections of nitric oxide synthase inhibitor l-name consolidate episodes of rem sleep in the rat. | dorsal mesopontine cholinergic neurons control rapid eye movement sleep (rems) and wakefulness and contain nitric oxide (no) synthase. to assess whether local inhibition of no synthase has distinct effects on sleep, n-nitro-l-arginine methyl ester, an no synthesis inhibitor (l-name, 80 mm), carbachol, a cholinergic agonist (2, 10 or 50 mm), or saline were microinjected (120-200 nl) into the dorsal mesopontine tegmentum in rats. sleep-wake cycles were monitored during the subsequent 6 h periods. ... | 1998 | 11382856 |
| selected contribution: regulation of sleep-wake states in response to intermittent hypoxic stimuli applied only in sleep. | recurrent sleep-related hypoxia occurs in common disorders such as obstructive sleep apnea (osa). the marked changes in sleep after treatment suggest that stimuli associated with osa (e.g., intermittent hypoxia) may significantly modulate sleep regulation. however, no studies have investigated the independent effects of intermittent sleep-related hypoxia on sleep regulation and recovery sleep after removal of intermittent hypoxia. ten rats were implanted with telemetry units to record the electr ... | 2001 | 11356818 |
| on-line detection of sleep-wake states and application to produce intermittent hypoxia only in sleep in rats. | sleep-disordered breathing is associated with adverse clinical consequences such as daytime sleepiness and hypertension. the mechanisms behind these associations have been studied in animal models, especially rats, but intermittent stimuli such as hypoxia have been applied without reference to sleep-wake states. to determine mechanisms underlying the adverse physiological consequences of stimuli associated with sleep-disordered breathing requires criteria for detection of sleep-wake states on-li ... | 2001 | 11356775 |
| rat strains that differ in corticotropin-releasing hormone production exhibit different sleep-wake responses to interleukin 1. | corticotropin-releasing hormone (crh) is a mediator of responses to a variety of stressors, including immune challenge. crh and the hypothalamic-pituitary-adrenal (hpa) axis constitute a negative feedback mechanism for actions of immunomodulators, such as interleukin (il) 1. crh is a potent inducer of waking, whereas il-1 induces slow-wave sleep (sws). we hypothesize that the complex changes in sleep-wake behavior during immune challenge are mediated in part by crh and its antagonism of il-1-ind ... | 2001 | 11340341 |
| modeling daily and subdaily cycles in rat sleep data. | we developed a statistical model for rat sleep-wake behavior over the 24-hour day; this model could be used for animals exposed to shorter cycles of light and dark conditions. rat behavior was classified either as "wake" or "sleep," as determined by analysis of electrophysiological data. the proposed model consists of three parts: the first two explain cyclic effects relating to the lighting conditions, whereas the last part reflects any acyclic effect. hypothesis tests were conducted on the mag ... | 1999 | 11315031 |
| effects of prolonged wakefulness on c-fos and ap1 activity in young and old rats. | recent studies have demonstrated that the immediate-early gene c-fos is induced in neuronal populations responsible for specific sleep-wake states. the induction of this gene may be functionally relevant to sleep homeostasis since without the gene mice (c-fos null) take longer to fall asleep and have a selective reduction in slow-wave sleep. this suggests that a build-up of c-fos during wakefulness increases the drive to sleep and lack of c-fos is associated with reduced sleep. sleep also has an ... | 2001 | 11311986 |
| microdialysis perfusion of 5-ht into hypoglossal motor nucleus differentially modulates genioglossus activity across natural sleep-wake states in rats. | 1. serotonin (5-hydroxytryptamine, 5-ht) excites hypoglossal (xii) motoneurons in reduced preparations, and it has been suggested that withdrawal of 5-ht may underlie reduced genioglossus (gg) muscle activity in sleep. however, systemic administration of 5-ht agents in humans has limited effects on gg activity. whether 5-ht applied directly to the xii motor nucleus increases gg activity in an intact preparation either awake or asleep has not been tested. 2. the aim of this study was to develop a ... | 2001 | 11306665 |
| deficiency of growth hormone-releasing hormone signaling is associated with sleep alterations in the dwarf rat. | the somatotropic axis, and particularly growth hormone-releasing hormone (ghrh), is implicated in the regulation of sleep-wake activity. to evaluate sleep in chronic somatotropic deficiency, sleep-wake activity was studied in dwarf (dw/dw) rats that are known to have a defective ghrh signaling mechanism in the pituitary and in normal lewis rats, the parental strain of the dw/dw rats. in addition, expression of ghrh receptor (ghrh-r) mrna in the hypothalamus/preoptic region and in the pituitary w ... | 2001 | 11306643 |
| auditory evoked potentials from auditory cortex, medial geniculate nucleus, and inferior colliculus during sleep-wake states and spike-wave discharges in the wag/rij rat. | click auditory evoked potentials (aep) were simultaneously recorded from the auditory cortex (acx), the medial geniculate nucleus (mgn), and the inferior colliculus (ic) in the freely moving wag/rij rat, to investigate state-dependent changes of the aep in different anatomical locations along the auditory pathway. | 2001 | 11306019 |
| brain extracellular glucose assessed by voltammetry throughout the rat sleep-wake cycle. | in the present study, cortical extracellular levels of glucose were monitored for the first time throughout the sleep-wake states of the freely moving rat. for this purpose, polygraphic recordings (electroencephalogram of the fronto-occipital cortices and electromyogram of the neck muscles) were achieved in combination with differential normal pulse voltammetry (dnpv) using a specific glucose sensor. data obtained reveal that the basal extracellular glucose concentration in the conscious rat is ... | 2001 | 11298804 |
| differential sensitivity to the wake-promoting actions of norepinephrine within the medial preoptic area and the substantia innominata. | mapping studies were conducted to delineate the site(s) of action for the arousal-enhancing actions of norepinephrine (ne) within the basal forebrain region encompassing the medial preoptic area (mpoa) and the substantia innominata (si). varying doses of ne, the beta-agonist, isoproterenol, or the alpha1-agonist, phenylephrine, were infused into the mpoa or si in the resting rat. infusions of ne (4 nmol, 16 nmo/150 nl), isoproterenol (15 nmol/150 nl), and phenylephrine (40 nmol/250 nl) into the ... | 2001 | 11256440 |
| prenatal nicotine alters vigilance states and achr gene expression in the neonatal rat: implications for sids. | maternal smoking is a major risk factor for sudden infant death syndrome (sids). the mechanisms by which cigarette smoke predisposes infants to sids are not known. we examined the effects of prenatal nicotine exposure on sleep/wake ontogenesis and central cholinergic receptor gene expression in the neonatal rat. prenatal nicotine exposure transiently increased sleep continuity and accelerated sleep/wake ontogeny in the neonatal rat. prenatal nicotine also upregulated nicotinic and muscarinic cho ... | 2001 | 11247836 |
| sleep in the blind mole rat spalax ehrenbergi. | the mole rat, spalax ehrenbergi, is an interesting species for sleep because of its pronounced specialization to a fossorial life. these rodents spend most of their life-time underground, and are less exposed to many of the environmental stimuli and challenges that are common to non-fossorial rodents. a prominent adaptation is their blindness, which is due to an atrophy of the eyes. | 2001 | 11247050 |
| dual effects of melatonin on barbiturate-induced narcosis in rats. | melatonin affects the circadian sleep/wake cycle, but it is not clear whether it may influence drug-induced narcosis. sodium thiopenthal was administered intraperitoneally into male rats pre-treated with melatonin (0.05, 0.5, 5 and 50 mg/kg). melatonin pre-treatment affected in a dual manner barbiturate narcosis, however, no dose-effect correlation was found. in particular, low doses reduced the latency to and prolonged the duration of barbiturate narcosis. in contrast, the highest dose of melat ... | 2001 | 11226639 |
| prepro-orexin mrna levels in the rat hypothalamus, and orexin receptors mrna levels in the rat hypothalamus and adrenal gland are not influenced by the thyroid status. | orexins are two recently discovered neuropeptides that play an important role in the regulation of food intake and in the regulation of the sleep-wake cycle. in this work we examined the effects of thyroid hormones on prepro-ox expression in the rat hypothalamus, and oxrs expression in the rat hypothalamus and adrenal gland. hypo- and hyperthyroidism were induced in adult male rats, and the levels of hypothalamic prepro-ox and oxrs mrna, and adrenal oxrs mrna were determined using semiquantitati ... | 2001 | 11226638 |
| discharge profiles of ventral tegmental area gaba neurons during movement, anesthesia, and the sleep-wake cycle. | although mesolimbic dopamine (da) transmission has been implicated in behavioral and cortical arousal, da neurons in the ventral tegmental area (vta) and substantia nigra pars compacta (snc) are not significantly modulated by anesthetics or the sleep-wake cycle. however, vta and sn non-da neurons evince increased firing rates during active wakefulness (aw) and rapid eye movement (rem) sleep, relative to quiet wakefulness. here we describe the effects of movement, select anesthetics, and the slee ... | 2001 | 11222665 |
| fos expression in orexin neurons varies with behavioral state. | the neuropeptide orexin (also known as hypocretin) is hypothesized to play a critical role in the regulation of sleep-wake behavior. lack of orexin produces narcolepsy, which is characterized by poor maintenance of wakefulness and intrusions of rapid eye movement (rem) sleep or rem sleep-like phenomena into wakefulness. orexin neurons heavily innervate many aminergic nuclei that promote wakefulness and inhibit rem sleep. we hypothesized that orexin neurons should be relatively active during wake ... | 2001 | 11222656 |
| the suprachiasmatic nucleus projects to posterior hypothalamic arousal systems. | the suprachiasmatic nucleus (scn) temporally organizes behavior in part by sustaining arousal during the wake period of the sleep/wake cycle to consolidate adaptive waking behavior. in this study, we demonstrate direct projections from the scn, in both the rat and the human brains, to perikarya and proximal dendrites of two groups of posterior hypothalamic neurons with axonal projections that suggest they are important in the regulation of arousal, one producing hypocretins (hct) and the other m ... | 2001 | 11209963 |
| effects of centrally administered orexin-b and orexin-a: a role for orexin-1 receptors in orexin-b-induced hyperactivity. | orexin-a and orexin-b are hypothalamic neuropeptides derived from a 130-amino acid precursor, prepro-orexin, and are potent agonists at both the orexin-1 (ox1) and orexin-2 (ox2) receptors. orexin-a has been ascribed a number of in vivo functions in the rat after intracerebroventricular (icv) administration, including hyperphagia, neuroendocrine modulation and a role in the regulation of sleep-wake function. the in vivo role of orexin-b is not as clear. | 2001 | 11205421 |
| nociceptive responsiveness during slow-wave sleep and waking in the rat. | brainstem neurons that are thought to modulate pain are reported to have state-dependent discharge rates. yet, the effect of behavioral state upon nociceptive transmission has not been well studied. therefore, we examined responses to noxious thermal stimulation of the rat hindpaw presented during different behavioral states. noxious thermal stimuli were applied to rats as they spontaneously cycled through waking and sleeping states. two different methods of heating the paw - a focused light bul ... | 2001 | 11204051 |
| spike sequences and their consequences. | spatio-temporal patterns of spikes have an advantage of representing information by their spike composition similar to words of languages. first we review the models of neuronal coding, then we discuss technical aspects of detecting spatio-temporal spike patterns. we argue by presenting data from rat hippocampus that spike trains recorded simultaneously from multiple pyramidal cells are not independent. their hidden dependency structure can be revealed by spike 'sequences', defined as a set of n ... | 2000 | 11165916 |
| rat sleep and eye movement density as biological markers of demyelinating disease. | myelin mutants provide an opportunity to study neurophysiological and behavioral effects of demyelination. the taiep rats are myelin mutants with progressive demyelination of the central nervous system (cns), resulting in five neurological symptoms: tremor, ataxia, immobility, epilepsy, and paralysis. the demyelination affects the brainstem, an important area in the control of sleep. this study compared eye movement density (emd) in taiep vs. normal control rats during paradoxical sleep (ps). it ... | 2000 | 11150558 |
| an automated system for recording and analysis of sleep in mice. | significant differences in many aspects of sleep/wake activity among inbred strains of mice suggest genetic influences on the control of sleep. a number of genetic techniques, including transgenesis, random and targeted mutagenesis, and analysis of quantitative trait loci may be used to identify genetic loci. to take full advantage of these genetic approaches in mice, a comprehensive and robust description of behavioral states has been developed. an existing automated sleep scoring algorithm, de ... | 2000 | 11145318 |
| the rat as an experimental model for sleep neurophysiology. | the aim of this study was to develop a sleep-wake recording system for rats that would yield results more comparable to those obtained from cats than those that are usually reported. for 18 male sprague-dawley rats, the authors combined measures of cortical and hippocampal electroencephalogram (eeg) and neck muscle electromyogram with the electrooculogram and pontine eeg, so that the behavioral states could be identified with greater confidence with the use of polygraphic criteria developed in t ... | 2000 | 11142656 |
| effect of electric foot shocks, immobilization, and corticosterone administration on the sleep-wake pattern in the rat. | knowledge concerning the impact of stressful situations on the sleep-wake pattern has been growing rapidly in the last decade. immobilization (imb) in rats elicits a significant increase of rapid eye movement (rem) sleep during the following 10 h. participation of the adrenergic system has been clearly shown in this effect. on the other hand, it is well known that the time of the circadian cycle in which the stressor is applied could influence the results. it is also well known that the activati ... | 2000 | 11134681 |
| effects of bilateral microinjections of ibotenic acid in the thalamic reticular nucleus on delta oscillations and sleep in freely-moving rats. | the thalamic reticular nucleus (nrt) consists of a large pool of gabaergic neurons located on each side on the anterior, lateral, and ventral surfaces of the dorsal thalamus. the nrt is divided up into sectors. the aim of this study was to investigate the effects of bilateral lesions of the nrt on sleep and sleep oscillations. only the results concerning delta oscillations will be reported here. as a first step we produced stereotaxically placed electrolytic lesions. the rats presented continuou ... | 2000 | 11123522 |
| muscarinic and pacap receptor interactions at pontine level in the rat: significance for rem sleep regulation. | cholinergic and pacapergic systems within the oral pontine reticular nucleus (pno) play a critical role in rem sleep generation in rats. in this present work, we have investigated whether rem sleep enhancement induced by carbachol (a cholinergic agonist) or pacap, depends on an interaction between muscarinic and pacap receptors. this hypothesis was tested by recording sleep-wake cycles in freely moving rats injected into the pno with pacap in combination with the muscarinic receptor antagonist a ... | 2000 | 11122360 |
| effects of lateral preoptic area application of orexin-a on sleep-wakefulness. | deficiency of orexin, a newly discovered hypothalamic peptide, is thought to lead to abnormal sleepiness and cataplexy in both human narcolepsy and animal models of the disease. as the poa contains extensive orexin terminals and is established as a sleep/arousal regulatory site, we evaluated a hypothesis that this site is a target for the arousal-inducing effects of orexin. orexin-a was microinjected into lateral preoptic area (ipoa) and the effects on sleep-wakefulness and brain temperature wer ... | 2000 | 11095491 |
| repeated 2-deoxy-d-glucose-induced glucoprivation attenuates fos expression and glucoregulatory responses during subsequent glucoprivation. | a condition of reduced responsiveness to hypoglycemia, known as hypoglycemia-associated autonomic failure (haaf), occurs in diabetic patients in the wake of a prior hypoglycemic episode. this condition suggests that hypoglycemia alters central glucose-sensing mechanisms. this experiment examined the effects of repeated 2-deoxy-d-glucose (2dg)-induced glucoprivation on subsequent 2dg-induced feeding and hyperglycemic responses in rats. fos immunoreactivity (ir) in adrenal medulla and brain sites ... | 2000 | 11078453 |
| hypothalamic arousal regions are activated during modafinil-induced wakefulness. | modafinil is an increasingly popular wake-promoting drug used for the treatment of narcolepsy, but its precise mechanism of action is unknown. to determine potential pathways via which modafinil acts, we administered a range of doses of modafinil to rats, recorded sleep/wake activity, and studied the pattern of neuronal activation using fos immunohistochemistry. to contrast modafinil-induced wakefulness with spontaneous wakefulness, we administered modafinil at midnight, during the normal waking ... | 2000 | 11069971 |
| neurotensin-induced bursting of cholinergic basal forebrain neurons promotes gamma and theta cortical activity together with waking and paradoxical sleep. | cholinergic basal forebrain neurons have long been thought to play an important role in cortical activation and behavioral state, yet the precise way in which they influence these processes has yet to be fully understood. here, we have examined the effects on the electroencephalogram (eeg) and sleep-wake state of basal forebrain administration of neurotensin (nt), a neuropeptide that has been shown in vitro to potently and selectively modulate the cholinergic cells. microinjection of (0.1-3.0 mm ... | 2000 | 11069953 |
| activity of adenosine deaminase in the sleep regulatory areas of the rat cns. | there are data to support the notion that adenosine (ado), a neuromodulator in the cns, is an important regulator of sleep homeostasis. it has been demonstrated that ado agonists and antagonists strongly impact upon sleep. in addition, the level of adenosine varies across the sleep/wake cycle and increases following sleep deprivation. adenosine deaminase (ada) is a key enzyme involved in the metabolism of ado. we questioned, therefore, whether there are differences in adenosine deaminase activit ... | 2000 | 11038259 |
| state dependent response of the locus caeruleus neurons to bladder distention. | the precise mechanism by which normal persons wake upon urinary sensation is unclear. the locus caeruleus in the pons is suggested to be involved in the activating systems for arousal. we evaluated the effects of bladder distention on the neural activity in the l. caeruleus under different states of anesthesia. | 2000 | 11025762 |
| adenosine as a biological signal mediating sleepiness following prolonged wakefulness. | recent reports from our laboratory have shown that extracellular adenosine levels selectively increase in basal forebrain during prolonged wakefulness in cats and rats. furthermore, microdialysis perfusion of adenosine into the basal forebrain (bf) increased sleepiness and decreased wakefulness in both the species, whereas perfusion of the a(1)-receptor-selective antagonist, cyclopentyl-1, 3-dimethylxanthine resulted in increased wakefulness, an observation similar to that found with caffeine or ... | 2000 | 11025338 |
| the hypocretins: excitatory neuromodulatory peptides for multiple homeostatic systems, including sleep and feeding. | the hypocretins are two neuropeptides of related sequence that are produced from a common precursor whose expression is restricted to 1, 100 large neurons of the rat dorsal-lateral hypothalamus. the hypocretins have been detected immunohistochemically in secretory vesicles at synapses of fibers that project to areas within the posterior hypothalamus that are implicated in feeding behaviors and hormone secretion and diverse targets in other brain regions and in the spinal cord, including several ... | 2000 | 11020209 |
| discharge patterns of neurons in cholinergic regions of the basal forebrain during waking and sleep. | a subset of neurons recorded in the magnocellular basal forebrain (mbf) of cats and rats exhibit elevated discharge rates during waking and rem sleep, and diminished discharge during sleep with cortical eeg synchrony (nonrem sleep). this pattern is observed in mbf neurons in cats with identified ascending projections, and in neurons located in cholinergic regions of the rat mbf. however, the cholinergic versus noncholinergic nature of recorded cells could not be determined with the extracellular ... | 2000 | 11000419 |
| unrelated course of subthalamic nucleus and globus pallidus neuronal activities across vigilance states in the rat. | the pallido-subthalamic pathway powerfully controls the output of the basal ganglia circuitry and has been implicated in movement disorders observed in parkinson's disease (pd). to investigate the normal functioning of this pathway across the sleep-wake cycle, single-unit activities of subthalamic nucleus (stn) and globus pallidus (gp) neurons were examined, together with cortical electroencephalogram and nuchal muscular activity, in non-anaesthetized head-restrained rats. stn neurons shifted fr ... | 2000 | 10998119 |
| sleep-wake effects following the selective 5-ht(1a) receptor antagonist p-mppi in the freely moving rat. | the 5-ht(1a) receptors appear to play an important role in the serotonergic modulation of sleep and waking. both presynaptic somatodendritic 5-ht(1a) autoreceptors and postsynaptic 5-ht(1a) heteroreceptors may be involved. the present study addressed the question of whether the selective 5-ht(1a) receptor antagonist 4-(2'-methoxy-phenyl)-1-[2'-(n-2"-pyridinyl)-p-iodobenzamido]-ethy l-p iperazine (p-mppi) affected sleep and waking and whether such an effect would be dose-related. polygraphic reco ... | 2000 | 10996044 |
| discharge modulation of rat dorsal raphe neurons during sleep and waking: effects of preoptic/basal forebrain warming. | in cats, putative serotonergic neurons (psns) recorded from the dorsal raphe nucleus (drn) across the sleep-wake cycle exhibit the so-called rapid eye movement sleep-off (rem-off) discharge pattern. since, the sleep-wake discharge patterns of drn neurons in behaving rats is poorly known, the present study examined this neuronal populations. the psns recorded in this study exhibited: (1) progressive decrease in discharge rate from waking to nrem to rem sleep; (2) long action potential duration, a ... | 2000 | 10967295 |
| role of the lateral preoptic area in sleep-related erectile mechanisms and sleep generation in the rat. | penile erections are a characteristic phenomenon of paradoxical sleep (ps), or rapid eye movement sleep. although the neural mechanisms of ps-related erections are unknown, the forebrain likely plays a critical role (schmidt et al., 1999). the preoptic area is implicated in both sleep generation and copulatory mechanisms, suggesting it may be a primary candidate in ps erectile control. continuous recordings of penile erections, body temperature, and sleep-wake states were performed before and up ... | 2000 | 10964969 |
| suprachiasmatic nucleus projections to the paraventricular thalamic nucleus in nocturnal rats (rattus norvegicus) and diurnal nile grass rats (arviacanthis niloticus). | the circadian pacemaker of the suprachiasmatic nucleus (scn) is likely to control the timing of the sleep-wake cycle in mammals by modulating the daily activity patterns of brain regions important in sleep and wakefulness. one such brain region is the paraventricular nucleus of the thalamus (pvt). in both nocturnal rats and the diurnal rodent arvicanthis niltoicus (nile grass rat), expression of fos (the product of the immediate-early gene c-fos) in the pvt increases at times of day when the ani ... | 2000 | 10960599 |
| il-1 is a mediator of increases in slow-wave sleep induced by crh receptor blockade. | we hypothesize that corticotropin-releasing hormone (crh), a regulator of the hypothalamic-pituitary-adrenal (hpa) axis, is involved in sleep-wake regulation on the basis of observations that the crh receptor antagonist astressin, after a delay of several hours, reduces waking and increases slow-wave sleep (sws) in rats. this delay suggests a cascade of events that begins with the hpa axis and culminates with actions on sleep regulatory systems in the central nervous system. one candidate mediat ... | 2000 | 10956236 |
| high doses of systemic dhea-sulfate do not affect sleep structure and elicit moderate changes in non-rem sleep eeg in rats. | the hormone dehydroepiandrosterone (dhea) and its metabolite dhea-sulfate (dheas) occur in huge quantities in the plasma as well as in the brain of vertebrates. to investigate whether dheas modulates sleep-wake behavior, we assessed the sleep response to three doses (25, 50, and 100 mg/kg) of intraperitoneally administered dheas, mixed with oil, in 8 rats. dheas injections produced dose-dependent and long-lasting elevations in the plasma levels of both dheas and dhea. dheas administration did no ... | 2000 | 10913777 |
| effects of glutamate agonist versus procaine microinjections into the basal forebrain cholinergic cell area upon gamma and theta eeg activity and sleep-wake state. | serving as the ventral, extra-thalamic relay from the brainstem reticular activating system to the cerebral cortex, basal forebrain neurons, including importantly the cholinergic cells therein, are believed to play a significant role in eliciting and maintaining cortical activation during the states of waking and paradoxical sleep. the present study was undertaken in rats to examine the effects upon electroencephalogram (eeg) activity and sleep-wake state of inactivating basal forebrain neurons ... | 2000 | 10886356 |
| diurnal variations in lipopolysaccharide-induced sleep, sickness behavior and changes in corticosterone levels in the rat. | inoculation of rats with microorganisms or microbial constituents that activate host defense promotes non-rapid eye movement sleep (non-rems) and suppresses rems. in this study, we evaluated circadian influences on the effects of lipopolysaccharide (lps) on sleep, sickness behavior and plasma corticosterone levels in the rat. three sets of experiments were performed. in each, the animals were intraperitoneally injected with vehicle for lps (30 microg/kg) during 2 consecutive days, at the beginni ... | 2000 | 10878499 |
| distribution of orexin-a and orexin-b (hypocretins) in the rat spinal cord. | orexin-a and orexin-b (also known as hypocretin-1 and hypocretin-2) are hypothalamic peptides that regulate feeding behavior, energy metabolism, and sleep-wake cycle. we determined the distribution of orexin-a and -b in the rat spinal cord, using sensitive radioimmunoassays and an immunohistochemical technique with three antisera specific for these orexins. orexins were distributed throughout the spinal cord, and their contents were highest in the cervical region. orexin fibers were concentrated ... | 2000 | 10876067 |
| effects of cholinomimetic injection into the brain stem reticular formation on halothane anesthesia and antinociception in rats. | the brain stem reticular formation plays an important role in determining consciousness and arousal. modulation of cholinergic neurotransmission in this region alters the sleep-wake cycle. in the present study, we examined the effect of the direct application of cholinergic agents into the pontine reticular nucleus on anesthetic requirements and recovery and antinociception in rats. sprague-dawley rats were implanted with 24-gauge guide cannulas 1.0 mm above the oral portion of pontine reticular ... | 2000 | 10869384 |
| infusion of adenylyl cyclase inhibitor sq22,536 into the medial pontine reticular formation of rats enhances rapid eye movement sleep. | microinjection of cholinergic and adenosinergic agonists into the medial pontine reticular formation of rats produces long lasting increases in the time spent in rapid eye movement sleep. several g-protein-coupled muscarinic and adenosinergic receptors share a common action of inhibition of adenylyl cyclase and inhibition of cyclic adenosine monophosphate. inhibition of cyclic adenosine monophosphate has been implicated in the mechanism of rapid eye movement sleep induction in the cat. we sought ... | 2000 | 10854762 |
| changes in rem sleep occurrence due to rhythmical auditory stimulation in the rat. | the effects of the rhythmical delivery of an auditory stimulus (1000 hz, from 50 to 100 db, 20 ms, every 20 s) on the pattern of rapid eye movement (rem) sleep occurrence was studied in the rat. the stimulation was simultaneously carried out on pairs of rats over 5 consecutive days (10-h recording sessions), during which a tone of increasing intensity (50, 63, 75, 88, 100 db) was used. in each experimental session, auditory stimulation was triggered by the rem sleep occurrence of one rat (rems-s ... | 2000 | 10854576 |
| neuromodulation of the prefrontal cortex during sleep: a microdialysis study in rats. | to test the hypothesis that biogenic amines of the prefrontal cortex are involved in state-dependent cortical and behavioural activation, changes in extracellular levels of serotonin (5-ht), dopamine (da), and noradrenaline (na) were determined during the sleep-wake cycle in freely moving rats using microdialysis probes with parallel eeg recording. serotonin gradually increased up to 450% during wakefulness (w) as compared to slow wave sleep (sws), before decreasing toward stable levels during t ... | 2000 | 10852212 |
| article reviewed: the novel brain neuropeptide, orexin-a, modulates the sleep-wake cycle of rats. | 2000 | 10828439 | |
| [oscillations in the oxidation-reduction potential of the brain tissue in rats developing during wakefulness and slow-wave sleep]. | variations of the brain cortex redox state potential (e) were recorded in freely moving white rats (mass of 300-350 g) with implanted platinum electrodes (with the platinum reference electrode in the nasal bone) during sleep-wake cycles. it was found that transitions from the slow-wave sleep to wakefulness were accompanied in the number of cortical areas (metabolic-active sites) by the e rise, while the transitions from the wakefulness to slow-ware sleep were associated with a drop of e. however ... | 2000 | 10822845 |
| inhibitory effects of low doses of melatonin on induction of preneoplastic liver lesions in a medium-term liver bioassay in f344 rats: relation to the influence of electromagnetic near field exposure. | we have previously reported that exposures of f344 male rats to both 900 mhz and 1.5 ghz electro-magnetic near fields (emfs) results in slightly decreased numbers and areas of glutathione s-transferase (gst-p)-positive liver foci, liver preneoplastic lesions in rats, in a medium-term liver bioassay (k. imaida, m. taki, t. yamaguchi, t. ito, s. watanabe, k. wake, a. aimoto, y. kamimura, n. ito, t. shirai, lack of promoting effects of the electromagnetic near-field used for cellular phones (929.2 ... | 2000 | 10814886 |
| down-regulation of orexin gene expression by severe obesity in the rats: studies in zucker fatty and zucker diabetic fatty rats and effects of rosiglitazone. | orexins (hypocretins) are lateral hypothalamic neuropeptides implicated in regulating feeding and the sleep-wake cycle. to study their possible relevance to obesity and diabetes, we measured hypothalamic prepro-orexin mrna levels in obese, normoglycemic zucker fatty (fa/fa) and in hyperglycemic, non-obese zucker diabetic fatty (zdf) rats. hypothalamic prepro-orexin mrna concentrations in zucker fatty rats were 31% lower than those in lean controls (0. 69+/-0.06 vs. 1.00+/-0.10 arbitrary units, p ... | 2000 | 10814839 |
| an instrumental method for long-term continuous rem sleep deprivation of neonatal rats. | the present study describes a new method for instrumental rem sleep deprivation (rsd) of neonatal rats. | 2000 | 10737334 |
| prenatal protein malnourished rats show changes in sleep/wake behavior as adults. | prenatal protein malnutrition significantly elevates brain levels of serotonin in rats, and these levels remain elevated throughout their lives. this biogenic amine is involved in the regulation of many physiological functions, including the normal sleep/wake cycle. the present study examined the effects of prenatal protein malnutrition on the sleep/wake cycle of freely moving adult rats. six prenatally protein malnourished (6% casein) and 10 well-nourished (25% casein) male rats (90-120-day-old ... | 2000 | 10733692 |
| molecular mechanisms of sleep-wake regulation: a role of prostaglandin d2. | prostaglandin (pg) d2 is a major prostanoid in the brains of rats and other mammals, including humans. when pgd synthase (pgds), the enzyme that produces pgd2 in the brain, was inhibited by the intracerebroventricular infusion of its selective inhibitors, i.e. tetravalent selenium compounds, the amount of sleep decreased both time and dose dependently. the amount of sleep of transgenic mice, in which the human pgds gene had been incorporated, increased several fold under appropriate conditions. ... | 2000 | 10724461 |
| sleep in the wistar-kyoto rat, a putative genetic animal model for depression. | the wistar-kyoto (wky) rat exhibits several behavioral and hormonal abnormalities often associated with depression. one of the hallmarks of depression consists of alterations in the sleep-wake cycle, particularly in rapid eye movement (rem) sleep. if the wky rat is indeed an animal model for depression, we hypothesized that it should also show sleep abnormalities relative to the control strain, the wistar (wis) rat under baseline conditions, wky rats showed a 50% increase in total rem sleep time ... | 2000 | 10718326 |
| the novel brain neuropeptide, orexin-a, modulates the sleep-wake cycle of rats. | orexin-a is a novel neuropeptide initially isolated from hypothalamic extracts but now known to be present in fibres distributed throughout the rat cns including many regions associated with sleep-wake regulation. the recognition of a particularly dense innervation of orexinergic nerves in the locus coeruleus, together with the observed increase in firing rate of locus coeruleus neurons following application of orexin-a in vitro, further highlighted a potential involvement of the peptide in modu ... | 2000 | 10712652 |
| effects of sleep deprivation on sleep and sleep eeg in three mouse strains: empirical data and simulations. | gene targeted mice can be used as models to investigate the mechanisms underlying sleep regulation. three commonly used background strains for gene targeting (129/ola, 129/svj and c57bl/6j) were subjected to 4-h and 6-h sleep deprivation (sd), and their sleep and sleep eeg were continuously recorded. the two-process model of sleep regulation has predicted the time course of slow-wave activity (swa) in nonrem sleep after several sleep-wake manipulations in humans and the rat [3] [9]. we tested th ... | 2000 | 10700548 |
| cholinergic modulation of respiratory brain-stem neurons and its function in sleep-wake state determination. | 1. shifts in behavioural state are controlled by reciprocal changes in discharge of cholinergic and aminergic groups of brain-stem/pontine neurons. during rapid eye movement (rem) sleep, cholinergic neurons are most active and aminergic neurons are least active. 2. significant changes occur in the central control of breathing during rem sleep; respiration rate increases in frequency and variability, brain-stem respiratory neuron discharge is generally enhanced and the outputs of some respiratory ... | 2000 | 10696542 |
| a sparse projection from the suprachiasmatic nucleus to the sleep active ventrolateral preoptic area in the rat. | the circadian clock of the suprachiasmatic nucleus (scn) may control the sleep-wake cycle by modulating the activity of brain regions important in sleep onset and maintenance, such as the ventrolateral preoptic area (vlpo). the aim of this study was to determine whether the vlpo receives direct projections from the scn. the retrograde tracer cholera toxin (beta subunit; ct beta) was injected into the vlpo of male rats and the scn was examined for the presence of labeled, vlpo-projecting neurons. ... | 2000 | 10683837 |
| a new method for continuous, long-term polysomnographic recording of neonatal rats. | many findings suggest that in altricial mammals neonatal rem sleep has developmental functions. however, investigations of these developmental functions has been hampered by technical limitations of the conventional polysomnographic (psg) recording technique. one limitation is that continuous (24 hour/day), long-term (weeks) psg recordings have not been achieved. a second limitation is that the metal screw electrodes and head plugs cemented to the skull cannot be removed to allow the neonate to ... | 2000 | 10678461 |
| diurnal variation in orexin a immunoreactivity and prepro-orexin mrna in the rat central nervous system. | orexins are a family of neuropeptides originally believed to be important mediators of food intake. the wide distribution of orexins and their receptors, however, has suggested other regulatory functions for these peptides including involvement in sleep and arousal mechanisms. in this study, we have demonstrated diurnal variation in orexin a immunoreactivity in the pons, from where locus coeruleus noradrenergic neurones innervate other brain areas to stimulate arousal, and in the preoptic/anteri ... | 2000 | 10674633 |
| 5-hydroxytryptophan, but not l-tryptophan, alters sleep and brain temperature in rats. | the precise role of serotonin (5-hydroxytryptamine) in the regulation of sleep is not fully understood. to further clarify this role for 5-hydroxytryptamine, the 5-hydroxytryptamine precursors l-tryptophan (40 and 80 mg/kg) and l-5-hydroxytryptophan (25-, 50-, 75-, 100 mg/kg) were injected intraperitoneally into freely behaving rats 15 min prior to dark onset, and subsequent effects on sleep-wake activity and cortical brain temperature were determined. l-5-hydroxytryptophan, but not l-tryptophan ... | 2000 | 10658624 |
| involvement of the caudal raphe nuclei in the feeding behavior of rats. | involvement of the caudal raphe nuclei (raphe pallidus, rpa; raphe magnus, rmg, and raphe obscurus, rob) in feeding behavior of adult rats was studied by measuring c-fos protein expression, in animals submitted to the "meal-feeding" model of food restriction in which the rats were fed ad libitum only from 7:00 to 9:00 h, for 15 days. the experimental groups submitted to chronic fasting, named 'search for food' (sf), 'ingestion of food' (if) and 'satiety of food' (saf) were scheduled after a prev ... | 2000 | 10657063 |
| density of perfused brain capillaries in the aged rat during the wake-sleep cycle. | structural and functional age-related changes in brain vasculature might affect the cerebral microcirculation. the present study evaluated the density of perfused brain capillaries and the perfusion fraction (perfused/existing capillaries) in aged rats (24 months) during the states of the wake-sleep cycle (quiet wakefulness, quiet sleep, active sleep) characterized by different levels of brain activation. the number of perfused capillaries was determined by intravascular injection of the fluores ... | 2000 | 10638443 |
| relationship of activity in the subthalamic nucleus-globus pallidus network to cortical electroencephalogram. | one of the functions of the excitatory subthalamic nucleus (stn) is to relay cortical activity to other basal ganglia structures. the response of the stn to cortical input is shaped by inhibition from the reciprocally connected globus pallidus (gp). to examine the activity in the stn-gp network in relation to cortical activity, we recorded single and multiple unit activity in stn and/or gp together with cortical electroencephalogram in anesthetized rats during various states of cortical activati ... | 2000 | 10632612 |
| dynamic changes in hypothalamic monoamines during sleep/wake cycles assessed by parallel eeg and microdialysis in the rat. | monoaminergic changes during sleep/wake cycles were investigated in the rostral hypothalamic areas since feeding, metabolism and sleep were shown to be causally related. thus, the microdialysis probe was located stereotaxically in the ventromedial and paraventricular nuclei and cemented together with cortical electrodes for eeg sleep recordings. the monoaminergic changes were extensively investigated. sampling of dialysates over six minutes in freely behaving rats showed an increase in 5-ht and ... | 1995 | 10607153 |
| studies on sleep/wake effects of serotonin reuptake inhibitors and receptor subtype involvement. | studies with the serotonin uptake inhibitors zimeldine and alaproclate show biphasic effects on the sleep/wake axis in rats and cats. zimeldine induced an initial waking response succeeded by a small sws-2 increase in rats. the waking increase was not blocked by the 5-ht2 antagonist ritanserin nor by the putative 5-ht1a antagonist (-)-alprenolol. in cats, zimeldine induced initial behavioural changes which were succeeded by a large sws-2 increase. alaproclate gave similar initial responses as zi ... | 1992 | 10607045 |
| pituitary crh receptor blockade reduces waking in the rat. | we have previously hypothesized that corticotropin-releasing hormone (crh) is involved in the regulation of physiological waking. central administration of crh receptor antagonists reduces spontaneous waking in the rat. some of the responses to central administration of crh receptor antagonists may be mediated by mechanisms involving the hypothalamic-pituitary-adrenal axis, either by direct actions on the hypothalamus or by actions at the level of the pituitary due to leakage of the antagonists ... | 1999 | 10604839 |
| adenosinergic modulation of rat basal forebrain neurons during sleep and waking: neuronal recording with microdialysis. | 1. the cholinergic system of the basal forebrain (bf) is hypothesized to play an important role in behavioural and electrocortical arousal. adenosine has been proposed as a sleep-promoting substance that induces sleep by inhibiting cholinergic neurons of the bf and brainstem. however, adenosinergic influences on the activity of bf neurons in naturally awake and sleeping animals have not been demonstrated. 2. we recorded the sleep-wake discharge profile of bf neurons and simultaneously assessed a ... | 1999 | 10601498 |
| mirtazapine, a mixed-profile serotonin agonist/antagonist, suppresses sleep apnea in the rat. | serotonin enhancing drugs, including l-tryptophan and, more recently, fluoxetine and paroxetine, have been tested as pharmacologic treatments for sleep apnea syndrome. although some patients have demonstrated reduced apnea expression after treatment with these compounds, this improvement has been restricted to nonrapid eye movement (nrem) sleep, with some patients showing no improvement. this study reports the effects of mirtazapine, an antidepressant with 5-ht(1) agonist as well as 5-ht(2) and ... | 1999 | 10588592 |
| the burst-suppression electroencephalogram. | the burst-suppression (bs) pattern of the eeg occurs in a rather limited number of conditions. it has been observed in deep stages of general anesthesia and in conjunction with sedative overdoses. it is also known to occur in the wake of cardiorespiratory arrest. undercutting of the cortex has been found to result in bs activity. rare neonatal epileptic encephalopathies also give rise to bs. our personal interest was prompted by the consistent finding of bs activity in rats following cerebral an ... | 1999 | 10578472 |
| sleep impairments in rats implanted with morphine pellets. | morphine pellets (2 x 75 mg) were subcutaneously implanted in rats and vigilance states (wakefulness, slow wave sleep and paradoxical sleep) were observed during ten days. significant impairment of each vigilance state distribution appeared during the first days of morphine dependence. although waking and slow wave sleep were not affected during the last days, paradoxical sleep duration was reduced during dependence. nevertheless, the sleep-wake circadian rhythm was not abolished. these results ... | 1999 | 10559705 |
| pituitary adenylyl cyclase-activating peptide: a pivotal modulator of glutamatergic regulation of the suprachiasmatic circadian clock. | the circadian clock in the suprachiasmatic nucleus (scn) of the hypothalamus organizes behavioral rhythms, such as the sleep-wake cycle, on a near 24-h time base and synchronizes them to environmental day and night. light information is transmitted to the scn by direct retinal projections via the retinohypothalamic tract (rht). both glutamate (glu) and pituitary adenylyl cyclase-activating peptide (pacap) are localized within the rht. whereas glu is an established mediator of light entrainment, ... | 1999 | 10557344 |
| gabaa receptor modulation of temperature sensitive neurons in the diagonal band of broca in vitro. | several regions of the brain, including the horizontal limb of the diagonal band of broca (hdb), contain neurons that are responsive to changes in local temperature. these neurons are hypothesized to participate in thermoregulation and sleep-wake control. the hdb contains a large number of gamma-aminobutyric acid (gaba) terminals, and it has many neurons that utilize gaba as a neurotransmitter. therefore, in this study we characterized the in vitro effects of the gabaa receptor agonist muscimol ... | 1999 | 10536201 |
| gadolinium chloride pretreatment prevents cafeteria diet-induced sleep in rats. | the liver kupffer cells constitute the largest population of fixed macrophages in the body and reside at a strategic position in liver sinusoids to interact with mediators from the gut. previously, we showed that cafeteria feeding increases sleep by a subdiaphragmatic mechanism and increases interleukin-1beta (il-1beta) mrna expression in rat liver and brain. thus, the aim of the present experiment was to test the hypothesis that macrophages, in particular liver kupffer cells, contribute to the ... | 1999 | 10505816 |
| choline acetyltransferase expression during periods of behavioral activity and across natural sleep-wake states in the basal forebrain. | the present study examined whether the expression of the messenger rna encoding the protein responsible for acetylcholine synthesis is associated with sleep-wakefulness. choline acetyltransferase messenger rna levels were analysed using a semi-quantitative assay in which reverse transcription was coupled to complementary dna amplification using the polymerase chain reaction. to examine the relationship between steady-state messenger rna and behavioral activity, rats were killed during the day (4 ... | 1999 | 10501461 |
| chronic, low-level exposure to the cholinesterase inhibitor dfp. ii. time course of behavioral state changes in rats. | rats were repeatedly administered with low doses of diisopropylfluorophosphate (dfp; 0.2 mg/kg/day, sc), an irreversible cholinesterase (che) inhibitor. control rats received a daily injection of oil vehicle or of saline. recordings of the sleep-wake states were obtained in the 6 h following 1, 3, 6, 9, 13, 17, and 21 injections, as well as 2, 4, and 19 days after 9-day treatment. dfp administration increased waking at the expense of slow-wave sleep (sws), but not of paradoxical sleep (ps); as a ... | 1999 | 10495004 |