Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| homeostatic regulation of sleep: a role for preoptic area neurons. | the median preoptic nucleus (mnpn) and the ventrolateral preoptic area (vlpoa) contain putative sleep-regulatory neurons that exhibit elevated discharge rates during sleep compared with waking. expression of c-fos protein immunoreactivity (ir) in gabaergic neurons in the mnpn and the vlpoa is high in spontaneously sleeping rats and in rats undergoing recovery sleep after sleep deprivation. however, it is unclear whether c-fos-ir in these neurons is evoked by increases in sleep pressure or by inc ... | 2006 | 16971526 |
| p2y receptor-mediated excitation in the posterior hypothalamus. | histaminergic neurons located in the posterior hypothalamus (tuberomamillary nucleus, tmn) project widely through the whole brain controlling arousal and attention. they are tonically active during wakefulness but cease firing during sleep. as a homeostatic theory of sleep involves atp depletion and adenosine accumulation in the brain, we investigated the role of atp and its analogues as well as adenosine on neuronal activity in the tmn. we show increased firing of rat tmn neurons by atp, adp, u ... | 2006 | 16965543 |
| memory-based detection of rare sound feature combinations in anesthetized rats. | it is unclear whether the ability of the brain to discriminate rare from frequently repeated combinations of sound features is limited to the normal sleep/wake cycle. we recorded epidural auditory event-related potentials in urethane-anesthetized rats presented with rare tones ('deviants') interspersed with frequently repeated ones ('standards'). deviants differed from standards either in frequency alone or in frequency combined with intensity. in both cases, deviants elicited event-related pote ... | 2006 | 16957608 |
| ghrelin and sleep-wake regulation. | 2007 | 16946077 | |
| firing properties of anatomically identified neurons in the medial septum of anesthetized and unanesthetized restrained rats. | cholinergic and gabaergic neurons in the medial septum-diagonal band of broca (ms-db) project to the hippocampus where they are involved in generating theta rhythmicity. so far, the functional properties of neurochemically identified ms-db neurons are not fully characterized. in this study, ms-db neurons recorded in urethane anesthetized rats and in unanesthetized restrained rats were labeled with neurobiotin and processed for immunohistochemistry against glutamic acid decarboxylase (gad), parva ... | 2006 | 16943562 |
| endogenous excitatory drive modulating respiratory muscle activity across sleep-wake states. | the concept of a tonic drive activating respiratory muscle in wakefulness but not sleep has been an important and enduring notion in respiratory medicine, not least because it is useful in modeling sleep effects on breathing and understanding the pathogenesis of sleep-related breathing disorders such as obstructive sleep apnea. however, a neurotransmitter substrate mediating respiratory muscle activation across sleep-wake states has not been identified. | 2006 | 16931636 |
| csf orexin a concentrations and expressions of the orexin-1 receptor in rat hippocampus after cardiac arrest. | orexins/hypocretins are neuropeptides that have various physiological effects, including the regulation of feeding behavior, neuroendocrine functions and sleep-wake cycles. recent studies have suggested that the orexin system may also be involved in brain ischemic reactions. it is also known that changes in sleep patterns, energy homeostasis and neuroendocrine functions are often occur in neurological conditions associated brain ischemia. in the current study, we investigated the time-dependent ... | 2006 | 16930690 |
| fast modulation of prefrontal cortex activity by basal forebrain noncholinergic neuronal ensembles. | traditionally, most basal forebrain (bf) functions have been attributed to its cholinergic neurons. however, the majority of cortical-projecting bf neurons are noncholinergic and their in vivo functions remain unclear. we investigated how bf modulates cortical dynamics by simultaneously recording </=50 bf single neurons along with local field potentials (lfps) from the prefrontal cortex (pfcx) in different wake-sleep states of adult rats. using stereotypical spike time correlations, we identifie ... | 2006 | 16928796 |
| sleep and brain monoamine changes produced by acute and chronic acetaldehyde administration in rats. | acetaldehyde, the most toxic metabolite of ethanol, has been implicated in many toxic effects of ethanol. in the present study, we used rats to investigate the possible changes on the sleep-wake cycle and brain regional concentrations of noradrenaline and serotonin after intraperitoneal administration of several doses of acetaldehyde. results showed that acetaldehyde significantly decreases the time spent in rapid eye movements sleep and wakefulness and increases the time spent in slow-wave slee ... | 2006 | 16920203 |
| central administration of neuropeptide y induces wakefulness in rats. | neuropeptide y (npy) is a well-characterized neuromodulator in the central nervous system, primarily implicated in the regulation of feeding. npy, orexins, and ghrelin form a hypothalamic food intake regulatory circuit. orexin and ghrelin are also implicated in sleep-wake regulation. in the present experiments, we studied the sleep-modulating effects of central administration of npy in rats. rats received intracerebroventricular injection of physiological saline or three different doses of npy ( ... | 2006 | 16914434 |
| sleep-wake study in an animal model of acute and chronic heat stress. | the study of the variations in different parameters of sleep-wake states following exposure to high environmental heat in three different age groups of freely moving rats have been presented in this paper. each age group of rats was subdivided in three group (i) acute heat stress--subjected to a single exposure for 4 h in the bod (biological oxygen demand) incubator at 38 degrees c; (ii) chronic heat stress--exposed for 21 days daily for 1 h in the incubator at 38 degrees c, and (iii) handling c ... | 2006 | 16899261 |
| adenosine and sleep homeostasis in the basal forebrain. | it is currently hypothesized that the drive to sleep is determined by the activity of the basal forebrain (bf) cholinergic neurons, which release adenosine (ad), perhaps because of increased metabolic activity associated with the neuronal discharge during waking, and the accumulating ad begins to inhibit these neurons so that sleep-active neurons can become active. this hypothesis grew from the observation that ad induces sleep and ad levels increase with wake in the basal forebrain, but surpris ... | 2006 | 16885223 |
| evaluation of the effect of chronic exposure to 137cesium on sleep-wake cycle in rats. | since the chernobyl accident, the most significant problem for the population living in the contaminated areas is chronic exposure by ingestion of radionuclides, notably (137)cs, a radioactive isotope of cesium. it can be found in the whole body, including the central nervous system. the present study aimed to assess the effect of (137)cs on the central nervous system and notably on open-field activity and the electroencephalographic pattern. rats were exposed up to 90 days to drinking water con ... | 2006 | 16876929 |
| serotonin and 5-hydroxy-indole-acetic acid contents in dorsal raphe and suprachiasmatic nuclei in normal, malnourished and rehabilitated rats under 24 h of sleep deprivation. | it has been discussed that serotonin (5-ht) could be involved in the effects of sleep deprivation (sd) and/or malnutrition (m) on the sleep-wake cycle. the aim of this work was to study the effects of the m, sd and its interaction on 5-ht and 5-hydroxy-indole-acetic acid (5-hiaa) contents in the dorsal raphe (dr) and the suprachiasmatic nuclei (scn), two sleep-wake cycle regulators. forty-eight puppets rats were obtained from mothers fed with low or normal casein diet. they were allocated in 3 g ... | 2006 | 16876773 |
| cholinergic regulation of the posterior medial thalamic nucleus. | we previously showed that the gabaergic nucleus zona incerta (zi) suppresses vibrissae-evoked responses in the posterior medial (pom) thalamus of the rodent somatosensory system. we proposed that this inhibitory incertothalamic pathway regulates pom responses during different behavioral states. here we tested the hypothesis that this pathway is modulated by the ascending brain stem cholinergic system, which regulates sleep-wake cycles and states of vigilance. we demonstrate that cholinergic inpu ... | 2006 | 16870838 |
| the sleep-enhancing effect of valerian inhalation and sleep-shortening effect of lemon inhalation. | we examined the effects of odorant inhalation on the sleep-wake states in rats. odorants used in the experiment were clove, jasmine, lavender, lemon, peppermint, pine, rose, sandalwood, valerian, and ylang-ylang. valerian and rose inhalation significantly prolonged the pentobarbital-induced sleeping time, whereas lemon inhalation significantly shortened it. the effect of valerian inhalation was markedly noticeable. in the anosmic rats, a significant effect of odorants on the pentobarbital sleep ... | 2006 | 16857858 |
| prenatal malnutrition and sleep states in adult rats: effects of restraint stress. | independently, prenatal malnutrition and psychological/physical stress have been shown to affect sleep architecture in adult rats. as malnutrition and stress commonly co-exist in malnourished human populations, the objective of the present study was to ascertain the combined effects of these two insults by examining sleep-wake parameters following a brief restraint stress in prenatally protein malnourished rats. the male offspring of rats provided with a protein deficient diet (6% casein) for 5 ... | 2006 | 16828813 |
| hippocampal synaptic plasticity and spatial learning are impaired in a rat model of sleep fragmentation. | sleep fragmentation, a symptom in many clinical disorders, leads to cognitive impairments. to investigate the mechanisms by which sleep fragmentation results in memory impairments, rats were awakened once every 2 min via 30 s of slow movement on an automated treadmill. within 1 h of this sleep interruption (si) schedule, rats began to sleep in the 90-s periods without treadmill movement. total non-rapid eye movement sleep (nrem) sleep time did not change over the 24 h of si, although there was a ... | 2006 | 16817877 |
| obestatin alters sleep in rats. | obestatin is a recently identified peptide derived from the ghrelin gene. ghrelin stimulates food intake whereas obestatin has an opposite effect in rats. previous experiments in our laboratory revealed that ghrelin also induces wakefulness in rats. the aim of the present experiments was to study the effect of obestatin on sleep. rats received intraperitoneal (n = 7; 16 or 64 microg/kg) or intracerebroventricular (i.c.v.; n = 11) injection of pyrogen-free isotonic nacl or obestatin (1, 4 and 16 ... | 2006 | 16806691 |
| p-cpa pretreatment reverses the changes in sleep and behavior following acute immobilization stress rats. | the effects of p-cpa (para-chlorophenylalanine) pretreatment was studied on the sleep-wake parameters and patterns of behavioral activities in an animal model of acute immobilization stress. for the experiments, young male charles foster rats were divided into three groups, subjected to (i) acute immobilization stress for four hours on specially designed wooden boards, (ii) a similar model of acute immobilization stress after pretreatment of p-cpa (injected through i.p. route), and (iii) control ... | 2006 | 16779920 |
| alpha-2 adrenergic regulation of pedunculopontine nucleus neurons during development. | rapid eye movement sleep decreases between 10 and 30 days postnatally in the rat. the pedunculopontine nucleus is known to modulate waking and rapid eye movement sleep, and pedunculopontine nucleus neurons are thought to be hyperpolarized by noradrenergic input from the locus coeruleus. the goal of the study was to investigate the possibility that a change in alpha-2 adrenergic inhibition of pedunculopontine nucleus cells during this period could explain at least part of the developmental decrea ... | 2006 | 16753270 |
| the orexin system regulates alcohol-seeking in rats. | 1. orexin-containing neurons have been implicated in feeding, sleep-wake cycles and more recently in drug-seeking behaviour. 2. pretreatment of alcohol-preferring (ip) rats with an orexin1 receptor antagonist (sb-334867, 20 mg kg(-1), intraperitoneally) completely abolished an olfactory cue-induced reinstatement of alcohol-seeking behaviour, and also attenuated alcohol responding under an operant fixed ratio regimen without affecting water responding. 3. the mrna encoding orexin within the hypot ... | 2006 | 16751790 |
| [analysis of rat 24h heart rate variability based on telemetry technology]. | in this study ecg signal of unstrained rat was recorded by telemetry device, and heart rate variability (hrv) was analyzed in order to evaluate 24h autonomic nervous activity. the results demonstrated an obvious circadian rhythm in the autonomic nervous activity: sympathetic activity being dominant during wake phase, and parasympathetic activity, dominant during sleep phase. the ratio of the low frequency to high frequency components in hrv power spectrum (lf/hf) fluctuates with the change in th ... | 2006 | 16706337 |
| serotonin turnover in different duration of sleep recovery in discrete regions of young rat brain after 24 h rem sleep deprivation. | sleep plays an important role in restorative function and serotonin (5-hydroxytryptamine: 5ht) equally plays important roles in sleep. though various studies have revealed the roles of 5ht in sleep/wake cycle, the mechanism involved is yet unclear. in the present study we investigated alteration of the 5ht turnover in various regions of the young rat brains after 24 hours (h) rem sleep (srem) deprivation to elucidate the roles of 5ht in sleep restoration function in the these regions. the 5ht tu ... | 2006 | 16697543 |
| prenatal ethanol exposure alters the expression of period genes governing the circadian function of beta-endorphin neurons in the hypothalamus. | sleep-wake disturbances and stress hyper-responsiveness have been observed in human neonates, children and adolescents who were exposed to alcohol during the prenatal period. using the laboratory rat as an animal model, we investigated whether fetal ethanol exposure during gestational days 10-21 affects the circadian function of the stress-axis regulatory beta-endorphin neurons in the hypothalamus. fetal ethanol-exposed rats showed abnormality in the circadian expression of proopiomelanocortin ( ... | 2006 | 16686691 |
| a systematic review of modafinil: potential clinical uses and mechanisms of action. | modafinil is a novel wake-promoting agent that has u.s. food and drug administration approval for narcolepsy and shift work sleep disorder and as adjunctive treatment of obstructive sleep apnea/hypopnea syndrome. modafinil has a novel mechanism and is theorized to work in a localized manner, utilizing hypocretin, histamine, epinephrine, gamma-aminobutyric acid, and glutamate. it is a well-tolerated medication with low propensity for abuse and is frequently used for off-label indications. the obj ... | 2006 | 16669720 |
| ghrelin-induced sleep responses in ad libitum fed and food-restricted rats. | ghrelin is an endogenous ligand for the growth hormone secretagogue receptor and a well-characterized food intake regulatory peptide. hypothalamic ghrelin-, neuropeptide y (npy)-, and orexin-containing neurons form a feeding regulatory circuit. orexins and npy are also implicated in sleep-wake regulation. sleep responses and motor activity after central administration of 0.2, 1, or 5 microg ghrelin in free-feeding rats as well as in feeding-restricted rats (1 microg dose) were determined. food a ... | 2006 | 16631138 |
| corticothalamic 5-9 hz oscillations are more pro-epileptogenic than sleep spindles in rats. | absence-related spike-and-wave discharges (swds) occur in the thalamocortical system during quiet wakefulness or drowsiness. in feline generalized penicillin epilepsy, swds develop from sleep spindles. in contrast, in genetic absence epilepsy rats from strasbourg (gaers), swds develop from wake-related 5-9 hz oscillations, which are distinct from spindle oscillations (7-15 hz). since these two oscillation types share common frequency bands and may contribute to swd genesis, it is important to co ... | 2006 | 16627566 |
| role of noradrenergic and gaba-ergic inputs in pedunculopontine tegmentum for regulation of rapid eye movement sleep in rats. | rapid eye movement (rem) sleep disturbance is associated with several psycho-behavioral disorders, hence, it is important to understand its neural mechanism of regulation. although it was known that the noradrenergic (na-ergic) neurons from locus coeruleus (lc) project to the pedunculopontine tegmentum (ppt), the role of noradrenaline (na) alone and in association with gaba, an inhibitory neurotransmitter, in ppt for rem sleep regulation was not known and was investigated in this study in freely ... | 2006 | 16616214 |
| electrophysiological diversity of the dorsal raphe cells across the sleep-wake cycle of the rat. | through their widespread projections to the entire brain, dorsal raphe cells participate in many physiological functions and are associated with neuropsychiatric disorders. in previous studies, the width of action potentials was used as a criterion to identify putative serotonergic neurons, and to demonstrate that cells with broad spikes were more active in wakefulness, slowed down their activity in slow wave sleep and became virtually silent during paradoxical sleep. however, recent studies rep ... | 2006 | 16613874 |
| orexins, energy balance, temperature, sleep-wake cycle. | 2006 | 16556904 | |
| the preoptic hypothalamus and basal forebrain play opposing roles in the descending modulation of sleep and wakefulness in infant rats. | recent findings in infant rats suggest that the preoptic area (poa) and/or basal forebrain (bf) contribute to developmental changes in sleep and wake organization between postnatal day 2 (p2) and p9. to examine the contributions of these forebrain areas to sleep and wakefulness, separate lesions of the poa or bf, or combined lesions (poa + bf), were performed at p9, and precollicular transections were performed at p2. in addition, modafinil, a drug of unknown mechanism of action the effects of w ... | 2006 | 16553791 |
| modulation of somatosensory evoked potentials during wake-sleep states and spike-wave discharges in the rat. | to clarify the cortical evoked responses in the primary somatosensory cortex of the rat under states of waking, slow-wave sleep (sws), paradoxical sleep (ps), and spike-wave discharges (swds), which are associated with absence seizure. | 2006 | 16553013 |
| amyloid beta peptide (25-35) activates protein kinase c leading to cyclooxygenase-2 induction and prostaglandin e2 release in primary midbrain astrocytes. | prostaglandins (pgs) are generated by the enzymatic activity of cyclooxygenase-1 and -2 (cox-1/2) and modulate several functions in the cns such as the generation of fever, the sleep/wake cycle, and the perception of pain. moreover, the induction of cox-2 and the generation of pgs has been linked to neuroinflammatory aspects of alzheimer's disease (ad). non-steroidal anti-inflammatory drugs (nsaids) that block cox enzymatic activity have been shown to reduce the incidence of ad in various epidem ... | 2006 | 16546299 |
| adenosine inhibits basal forebrain cholinergic and noncholinergic neurons in vitro. | adenosine has been proposed as a homeostatic "sleep factor" that promotes the transition from waking to sleep by affecting several sleep-wake regulatory systems. in the basal forebrain, adenosine accumulates during wakefulness and, when locally applied, suppresses neuronal activity and promotes sleep. however, the neuronal phenotype mediating these effects is unknown. we used whole-cell patch-clamp recordings in in vitro rat brain slices to investigate the effect of adenosine on identified choli ... | 2006 | 16542780 |
| tonic activity of alpha1 adrenergic receptors of the medial preoptic area contributes towards increased sleep in rats. | several studies have suggested that noradrenergic afferents to the medial preoptic area might be involved in hypnogenesis and in lowering the body temperature, and that the alpha1 adrenergic receptors might be mediating these responses. this study was undertaken to find out the changes in sleep-wakefulness and body temperature in rats, when these adrenergic receptors of the medial preoptic area are blocked by alpha1 selective antagonist, prazosin. adult male wistar rats were chronically implante ... | 2006 | 16533567 |
| gaba(a) receptor modulation of 5-ht neuronal firing in the median raphe nucleus: implications for the action of anxiolytics. | 5-ht neurones in the median raphe nucleus (mrn) are involved in anxiety and the sleep/wake cycle. here, using in vitro electrophysiology, we examined if the firing of mrn 5-ht neurones is regulated by gaba(a) receptors. the gaba(a) receptor agonists thip and muscimol caused concentration dependent inhibition of mrn 5-ht neurones. the gaba(a) receptor antagonist bicuculline blocked the responses to thip and muscimol. bicuculline alone increased the basal firing activity. responses to thip were en ... | 2006 | 16531019 |
| sleep induction and temperature lowering by medial preoptic alpha(1) adrenergic receptors. | changes in sleep-wakefulness (s-w) and body temperature (t(b)) on administration of alpha(1) agonist (methoxamine) and antagonist (prazosin) into the medial preoptic area (mpoa) were studied in rats. presynaptic catecholaminergic terminals of the mpoa were destroyed by injecting 6-hydroxydopamine at the ventral noradrenergic bundle (vna), before administration of the drugs. microinjection of 0.05 microg methoxamine induced sleep, though 0.1 microg prazosin produced no change in s-w. on the other ... | 2006 | 16529782 |
| inhibition of serotonergic medullary raphe obscurus neurons suppresses genioglossus and diaphragm activities in anesthetized but not conscious rats. | although exogenous serotonin at the hypoglossal motor nucleus (hmn) activates the genioglossus muscle, endogenous serotonin plays a minimal role in modulating genioglossus activity in awake and sleeping rats (sood s, morrison jl, liu h, and horner rl. am j respir crit care med 172: 1338-1347, 2005). this result therefore implies that medullary raphe neurons also play a minimal role in the normal physiological control of the hmn, but this has not yet been established because raphe neurons release ... | 2006 | 16484356 |
| cold exposure and sleep in the rat: effects on sleep architecture and the electroencephalogram. | acute exposure to low ambient temperature modifies the wake-sleep cycle due to stage-dependent changes in the capacity to regulate body temperature. this study was carried out to make a systematic analysis of sleep parameters during the exposure to different low ambient temperatures and during the following recoveries at ambient temperature 24 degrees c. | 2005 | 16477956 |
| effects of selective dopamine d4 receptor antagonist, l-741,741, on sleep and wakefulness in the rat. | the influence of the dopamine system upon sleep/wake states is not fully understood. to date, the role of dopamine d4 receptor has not been studied. the aim of this work is to study the influence of dopamine d4 receptor upon sleep/wake states in male rats. male wistar rats were implanted with electroencephalography and electromyography electrodes for sleep recording. sleep/wake times were compared in rats first treated with control solution (vehicle) and the day after treated with a potent and h ... | 2006 | 16457926 |
| evoked response potential markers for anesthetic and behavioral states. | the rodent whisker sensory system is a commonly used model of cortical processing; however, anesthetics cause profound differences in the shape and timing of evoked responses. evoked response studies, especially those that use spatial mapping techniques, such as fmri or optical imaging, will thus show significantly different results depending on the anesthesia used. to describe the effect of behavioral states and commonly used anesthetics, we characterized the early surface-evoked response poten ... | 2006 | 16455771 |
| inhibition of caspase-1 in rat brain reduces spontaneous nonrapid eye movement sleep and nonrapid eye movement sleep enhancement induced by lipopolysaccharide. | evidence suggests that il-1beta is involved in promoting physiological nonrapid eye movement (nrem) sleep. il-1beta has also been proposed to mediate nrem sleep enhancement induced by bacteria or their components. mature and biologically active il-1beta is cleaved from an inactive precursor by a cysteinyl aspartate-specific protease (caspase)-1. this study aimed to test the hypothesis that inhibition in brain of the cleavage of biologically active il-1beta will reduce in rats both spontaneous nr ... | 2006 | 16455762 |
| serotonergic neuron diversity: identification of raphe neurons with discharges time-locked to the hippocampal theta rhythm. | the serotonergic system plays a key role in the regulation of brain states, and many of the known features of serotonergic neurons appear to match this function. midbrain raphe nuclei provide a diffuse projection to all regions of the forebrain, and raphe neurons exhibit a slow metronome-like activity that sets the ambient levels of serotonin across the sleep-wake cycle. serotonergic cells have also been implicated, however, in a variety of more specific functions that can hardly be related to t ... | 2006 | 16418294 |
| identification of wake-active dopaminergic neurons in the ventral periaqueductal gray matter. | recent evidence suggests that dopamine plays an important role in arousal, but the location of the dopaminergic neurons that may regulate arousal remains unclear. it is sometimes assumed that the dopaminergic neurons in the ventral tegmental area that project to the prefrontal cortex and striatum may regulate the state of arousal; however, the firing of these dopaminergic neurons does not correlate with overall levels of behavioral wakefulness. we identified wake-active dopaminergic neurons by c ... | 2006 | 16399687 |
| age-related changes in adenosine metabolic enzymes in sleep/wake regulatory areas of the brain. | the impact of age on the enzymatic activities of adenosine metabolic enzymes, i.e., adenosine deaminase, adenosine kinase, cytosolic- and ecto-5'-nucleotidase have been assessed in the brain sleep/wake regulatory areas of young, intermediate and old rats (2, 12 and 24 months, respectively). there were significant spatial differences in the distribution of enzymes of adenosine metabolism in the brain. age did not impact on the enzymatic activity of adenosine deaminase. adenosine kinase activity i ... | 2006 | 16399217 |
| neuropeptide-y y2-receptor agonist, pyy3-36 promotes non-rapid eye movement sleep in rat. | pyy3-36 is a major component of the gut-brain axis and peripheral administration has been reported to exert significant effects on feeding, brain function and is more selective for neuropeptide y2 receptor. therefore, we investigated the effects of nocturnal intraperitoneal administration of single doses of pyy3-36 (30 and 100 microg/kg i.p.) on food intake, water intake and the sleep-wake cycle in rats. sleep recordings were carried out in male sprague-dawley rats implanted with cortical electr ... | 2006 | 16378653 |
| afferents to the orexin neurons of the rat brain. | emotions, stress, hunger, and circadian rhythms all promote wakefulness and behavioral arousal. little is known about the pathways mediating these influences, but the orexin-producing neurons of the hypothalamus may play an essential role. these cells heavily innervate many wake-promoting brain regions, and mice lacking the orexin neurons have narcolepsy and fail to rouse in response to hunger (yamanaka et al. [2003] neuron 38:701-713). to identify the afferents to the orexin neurons, we first i ... | 2006 | 16374809 |
| nitric oxide from the laterodorsal tegmental neurons: its possible retrograde modulation on norepinephrine release from the axon terminal of the locus coeruleus neurons. | nitric oxide released from the cholinergic neurons in the pons may play important roles in sleep-wake regulation. however, there are few reports demonstrating the mechanisms of nitric oxide release in the cholinergic neurons in the pons. the present study investigated the effects of drug delivery of n-methyl-d-aspartic acid on nitric oxide and the neurotransmitters released in the laterodorsal tegmental nucleus (ldt), one of the major cholinergic cell groups in the pons, in rats by in vivo micro ... | 2006 | 16368196 |
| vasopressin induces depolarization and state-dependent firing patterns in rat thalamic paraventricular nucleus neurons in vitro. | the thalamic midline paraventricular nucleus (pvt) is prominently innervated by vasopressin-immunoreactive neurons from the suprachiasmatic nucleus (scn), site of the brain's biological clock. using patch-clamp recordings in slice preparations taken from wistar rats during the subjective day, we examined 90 pvt neurons for responses to bath-applied avp (0.5-2 microm; 1-3 min). in current clamp at resting membrane potentials (-65 +/- 1 mv), pvt neurons displayed low-threshold spikes (ltss) and bu ... | 2006 | 16339383 |
| immunolocalization of ecto-nucleoside triphosphate diphosphohydrolase 3 in rat brain: implications for modulation of multiple homeostatic systems including feeding and sleep-wake behaviors. | three anti-peptide antisera were raised against three distinct amino acid sequences of ecto-nucleoside triphosphate diphosphohydrolase 3 (ntpdase3), characterized by western blot analyses, and used to determine the distribution of ntpdase3 protein in adult rat brain. the three antisera all yielded similar immunolocalization data, leading to increased reliability of the results obtained. unlike ntpdase1 and ntpdase2, ntpdase3 immunoreactivity was detected exclusively in neurons. immunoreactivity ... | 2006 | 16338080 |
| further structure-activity relationship studies of piperidine-based monoamine transporter inhibitors: effects of piperidine ring stereochemistry on potency. identification of norepinephrine transporter selective ligands and broad-spectrum transporter inhibitors. | 4-(4-chlorophenyl)piperidine analogues each bearing a thioacetamide side chain appendage similar to that found in the wake-promoting drug modafinil have been synthesized. the transporter inhibitory activity of both the cis and trans isomers of these 3,4-disubstituted piperidines in both their (+)- and (-)-enantiomeric forms was determined. these studies reveal that the (-)-cis analogues exhibit dopamine transporter/norepinephrine transporter (dat/net) selectivity as was previously reported for t ... | 2005 | 16335921 |
| a versatile, low-cost adaptor for stereotaxic and electrophysiologic spinal preparations in juvenile and adult rodents. | rats and mice provide excellent models for normal spinal cord physiology, traumatic spinal cord injury, and various disease states. alternative and improved methodologies for experimental spinal preparations are desirable, particularly in the wake of expanding neuroscience technology, such as the diverse array of transgenic mice now available, and exciting new therapeutic approaches, including transplantation and gene therapy. this report describes a simple, low-cost instrument for spinal prepar ... | 2005 | 16325015 |
| cyclic nucleotides modulate genioglossus and hypoglossal responses to excitatory inputs in rats. | previous studies modulating pharyngeal muscle activity with pharmacologic approaches have targeted membrane receptors on pharyngeal motoneurons. whether modulation of intracellular pathways can increase pharyngeal muscle activity, however, has not been investigated but is relevant to pharmacologic treatments of obstructive sleep apnea. | 2006 | 16322643 |
| smad-dependent alterations of ppt cholinergic neurons as a pathophysiological mechanism of age-related sleep-dependent memory impairments. | in humans, memory impairments are highly prevalent in the aged population, but their functional and structural origins are still unknown. we hypothesized that circadian rhythm alterations may predict spatial memory impairment in aged rats. we demonstrate an association between sleep/wake circadian rhythm disturbances (non-rem sleep fragmentation) and spatial memory impairments in aged rats. we show by light and electron microscopy that these age-related disruptions in circadian rhythm and spatia ... | 2006 | 16316709 |
| beneficial effects of regular exercise on sleep in old f344 rats. | with aging there is a significant decline in the normal architecture of sleep and a reduction in the diurnal amplitude of core body temperature. regular moderate exercise has been shown to have a positive impact in the elderly and here we investigate whether sleep-wake patterning can also be improved. young (3 months) and old (22 months) f344 rats were exercised once a day for 50min at night onset over an 8-week period. thereafter, polysomnographic recordings were obtained immediately after exer ... | 2006 | 16309796 |
| insomnia following hypocretin2-saporin lesions of the substantia nigra. | the neuropeptide hypocretin, also known as orexin, has been implicated in waking since its deletion leads to the sleep disorder narcolepsy. hypocretin neurons project to major arousal areas, and in an effort to determine which region is responsible for the changes in sleep-wake architecture we have developed the neurotoxin hypocretin2-saporin, which lesions hypocretin receptor bearing neurons. here, in rats, we investigate the effects of hypocretin2-saporin lesions of the substantia nigra and ve ... | 2006 | 16289583 |
| nuclear parcellation of certain immunohistochemically identifiable neuronal systems in the midbrain and pons of the highveld molerat (cryptomys hottentotus). | the present paper details our findings following immunohistochemical examination of the midbrain and pons of the highveld molerat (cryptomys hottentotus) using antibodies for vesicular acetylcholine transporter (cholinergic neurons), tyrosine hydroxylase (dopaminergic and noradrenergic neurons), and serotonin (serotonergic neurons). the aim was to see if, in this microphthalmic rodent that lacks a distinct circadian rhythm, the nuclei involved in aspects of visual processing and the sleep-wake c ... | 2006 | 16289497 |
| a quartet neural system model orchestrating sleep and wakefulness mechanisms. | physiological knowledge of the neural mechanisms regulating sleep and wakefulness has been advanced by the recent findings concerning sleep/wakefulness-related preoptic/anterior hypothalamic and perifornical (orexin-containing)/posterior hypothalamic neurons. in this paper, we propose a mathematical model of the mechanisms orchestrating a quartet neural system of sleep and wakefulness composed of the following: 1) sleep-active preoptic/anterior hypothalamic neurons (n-r group); 2) wake-active hy ... | 2006 | 16282204 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |