| analgesic effect of intrathecally administered orexin-a in the rat formalin test and in the rat hot plate test. | 1. orexin-a and orexin-b (also known as hypocretin-1 and hypocretin-2) are hypothalamic peptides and regulate feeding behaviour, energy metabolism and the sleep-wake cycle. orexin-a binds equally to both orexin-1 and orexin-2 receptors, while orexin-b has a preferential affinity for orexin-2 receptors. 2. orexins are also known to be concentrated in superficial laminae of the spinal dorsal horn, and orexin-a and orexin-1 receptors are found in the dorsal root ganglion cells. 3. in the present st ... | 2002 | 12208773 |
| serotonin inputs to inspiratory laryngeal motoneurons in the rat. | serotonergic neurons are distributed widely throughout the central nervous system and exert a tonic influence on a range of activities in relation to the sleep-wake cycle. previous morphologic and functional studies have indicated a role for serotonin in control of laryngeal motoneurons. in the present study, we used a combination of intracellular recording, dye-filling, and immunocytochemistry in rats to demonstrate close appositions between serotonin immunoreactive boutons and posterior cricoa ... | 2002 | 12209844 |
| copulatory activity increases slow-wave sleep in the male rat. | it is believed that sexual activity increases the need to sleep in many species. however, the relationship between copulatory activity and sleep has been poorly studied. several studies have observed variations in the sleep of female rats and women as a function of their reproductive state. these effects have been correlated with the effects of female steroid hormones, but not with sexual activity. the aim of the present study was to evaluate the sleep-wake pattern of male rats immediately after ... | 2002 | 12220320 |
| immunostaining of cholinergic pontomesencephalic neurons for alpha 1 versus alpha 2 adrenergic receptors suggests different sleep-wake state activities and roles. | cholinergic neurons of the pontomesencephalic tegmentum play a critical role in paradoxical sleep, when, according to single unit recording of 'possibly' cholinergic neurons, they fire maximally. the profile of activity of the cholinergic neurons may be determined by noradrenergic locus coeruleus neurons that are active during waking and silent during paradoxical sleep. indeed, a permissive role of the noradrenergic neurons in paradoxical sleep has been proposed based upon an inhibitory action o ... | 2002 | 12220555 |
| selective action of orexin (hypocretin) on nonspecific thalamocortical projection neurons. | as is evident from the pathological consequences of its absence in narcolepsy, orexin (hypocretin) appears to be critical for the maintenance of wakefulness. via diffuse projections through the brain, orexin-containing neurons in the hypothalamus may act on a number of wake-promoting systems. among these are the intralaminar and midline thalamic nuclei, which project in turn in a widespread manner to the cerebral cortex within the nonspecific thalamocortical projection system. testing the effect ... | 2002 | 12223534 |
| relationship between low-dose amphetamine-induced arousal and extracellular norepinephrine and dopamine levels within prefrontal cortex. | despite the well-known and potent arousal-enhancing effects of amphetamine (amph)-like stimulants, the neurobiological substrates of amph-induced arousal have rarely been examined explicitly. available evidence suggests the possible participation of noradrenergic and/or dopaminergic systems in the arousal-enhancing actions of amph-like stimulants. the current studies examined the extent to which low-dose amph-induced increases in waking are related to amph-induced increases in extracellular nore ... | 2002 | 12325041 |
| sleep-wake effects of yohimbine and atropine in rats with a clomipramine-based model of depression. | the present study examined the sleep-wake cycle effects of microinjections of yohimbine, an adrenergic antagonist, and atropine, a cholinergic antagonist, into the cerebral ventricle of clomipramine-induced depressed rats. yohimbine microinjection caused a significant reduction in the total duration and the number of rem sleep episodes compared to control saline injections. atropine microinjection caused a significant reduction in the total duration and the number of rem sleep episodes without c ... | 2002 | 12352610 |
| cellular localization of cyclooxygenase-1 and cyclooxygenase-2 in the normal mouse, rat, and human retina. | prostaglandins, synthesized by cyclooxygenase (cox), regulate diverse neurophysiological actions such as regulation of autonomic responses, transmission of pain, generation of fever, control of sleep-wake cycle, synaptic signaling, and cross-talk between neurons and glia in the central nervous system. although prostaglandins have been widely studied in the anterior segment tissues of the eye, relatively little is known about prostaglandins in the neural retina. by using immunohistochemistry, we ... | 2002 | 12355421 |
| region selective alterations of soluble guanylate cyclase content and modulation in brain of cirrhotic patients. | modulation of soluble guanylate cyclase (sgc) by nitric oxide (no) is altered in brain from experimental animals with hyperammonemia with or without liver failure. the aim of this work was to assess the content and modulation of sgc in brain in chronic liver failure in humans. expression of the alpha-1, alpha-2, and beta-1 subunits of sgc was measured by immunoblotting in autopsied frontal cortex and cerebellum from cirrhotic patients and controls. the contents of alpha-1 and alpha-2 subunits of ... | 2002 | 12395325 |
| single cell activity patterns of pedunculopontine tegmentum neurons across the sleep-wake cycle in the freely moving rats. | microinjections of the excitatory amino acid, l-glutamate into the cholinergic cell compartment of the pedunculopontine tegmentum (ppt) of the rat induces both wakefulness and/or rapid eye movement (rem) sleep depending on the glutamate dosage. however, no studies have systematically recorded the electrical activity of these cells in the freely moving rat across the sleep-wake cycle. in this study, we have recorded the spontaneous activity patterns of single ppt cells (n = 70) in the freely movi ... | 2002 | 12404515 |
| indirect projections from the suprachiasmatic nucleus to the ventrolateral preoptic nucleus: a dual tract-tracing study in rat. | the suprachiasmatic nucleus (scn) contains a master clock for most circadian rhythms in mammals, including daily sleep-wake cycles. the ventrolateral preoptic nucleus (vlpo) plays a key role in sleep generation and, as such, might be an important target of the scn circadian signal. however, direct scn projections to the vlpo are limited, suggesting that most of the scn output to the vlpo might be conveyed indirectly. we examined this possibility by microinjecting selected known major targets of ... | 2002 | 12405980 |
| diurnal and nocturnal rodents show rhythms in orexinergic neurons. | orexin (orx) a and b (hypocretins) are excitatory neuropeptides produced by neurons of the lateral hypothalamus that have been implicated in the regulation of the sleep-wake cycle. in rats, fos (the product of the cfos gene) expression shows daily rhythms in areas involved in sleep and wakefulness and orexinergic neurons show elevated fos expression during the night. the present study directly compared the daily pattern of fos expression in orexinergic neurons in diurnal (a. niloticus; grass rat ... | 2002 | 12419515 |
| influence of sleep disturbance on steroid 5alpha-reductase mrna levels in rat brain. | sleep deprivation has been shown to affect the production of steroid hormones in peripheral steroidogenic organs, but little is known about the influence of sleep disturbance on the metabolism of steroid hormones in the brain. to elucidate a possible association of the sleep-wake cycle with brain neurosteroid metabolism, the influence of short-term sleep disturbance on the expression of mrna encoding steroid 5alpha-reductase, the enzyme converting progesterone and other steroid hormones to their ... | 2002 | 12421601 |
| sleep-wake effects of meta-chlorophenyl piperazine and mianserin in the behaviorally depressed rat. | the present study examined the effects of meta-chlorophenyl piperazine (mcpp) and mianserin on the sleep-wake cycle of the clomipramine-induced behaviorally screened depressed rats. six-hour polygraphic recordings were made between 06:00 and 12:00 h, after a single injection of either saline or mianserin or mcpp into the lateral cerebral ventricle (i.c.v.) of both the depressed (n=12) and control rats (n=12). the injection of mcpp in the depressed rats caused a significant reduction in the total ... | 2002 | 12433592 |
| nicotinic excitation of rat hypoglossal motoneurons. | hypoglossal motoneurons (hmns), which innervate the tongue muscles, are involved in several important physiological functions, including the maintenance of upper airway patency. the neural mechanisms that affect hmn excitability are therefore important determinants of effective breathing. obstructive sleep apnea is a disorder characterized by recurrent collapse of the upper airway that is likely due to decline of pharyngeal motoneuron activity during sleep. because cholinergic neuronal activity ... | 2002 | 12435424 |
| [potentiometric monitoring of the redox state of brain structures of freely-moving rats in sleep-wake cycles]. | variations of brain tissue redox state potential (e) of freely-moving white rats (300-350 g) in cycles of wakefulness (w), slow-wave sleep (sws), and paradoxical sleep (ps) were measured by platinum electrodes symmetrically implanted into the frontal and occipital cortices and hippocampus. in addition, emg of neck muscles and general motor activity of animals were recorded. the common reference electrode was implanted in the nasal bone. it was shown that in some brain sites (called active), epis ... | 2002 | 12449837 |
| the rat ponto-medullary network responsible for paradoxical sleep onset and maintenance: a combined microinjection and functional neuroanatomical study. | the neuronal network responsible for paradoxical sleep (ps) onset and maintenance has not previously been identified in the rat, unlike the cat. to fill this gap, this study has developed a new technique involving the recording of sleep-wake states in unanaesthetized head-restrained rats whilst locally administering pharmacological agents by microiontophoresis from glass multibarrel micropipettes, into the dorsal pontine tegmentum and combining this with functional neuroanatomy. pharmacological ... | 2002 | 12453060 |
| microinjection of neostigmine into the pontine reticular formation of c57bl/6j mouse enhances rapid eye movement sleep and depresses breathing. | the cholinergic model of rapid eye movement (rem) sleep has contributed significantly to understanding sleep neurobiology and sleep-dependent respiratory depression. the model has been used extensively in cat and rat, but no previous studies have demonstrated cholinergic rem sleep enhancement in mouse. the present study used microinjection of neostigmine into pontine reticular formation of mouse to test the hypothesis that enhancing pontine cholinergic neurotransmission would cause increased rem ... | 2002 | 12489888 |
| specific contributions of the basal forebrain corticopetal cholinergic system to electroencephalographic activity and sleep/waking behaviour. | the present study examined the role of the basal forebrain corticopetal cholinergic projection in the regulation of cortical electroencephalographic activity across sleep/wake states in rats. selective lesions of this projection were effected by local intraparenchymal infusions of the immunotoxin 192 igg-saporin. lesions spared the septo-hippocampal cholinergic system, as well as p75-receptor-bearing noncholinergic neurons in the suprachiasmatic nucleus. relative to sham-lesioned control animals ... | 2002 | 12492440 |
| brain-immune interactions in sleep. | this chapter discusses various levels of interactions between the brain and the immune system in sleep. sleep-wake behavior and the architecture of sleep are influenced by microbial products and cytokines. on the other hand, sleep processes, and perhaps also specific sleep states, appear to promote the production and/or release of certain cytokines. the effects of immune factors such as endotoxin and cytokines on sleep reveal species specificity and usually strong dependence on parameters such a ... | 2002 | 12498102 |
| preoptic area warming inhibits wake-active neurons in the perifornical lateral hypothalamus. | activation of the preoptic area (poa) warm sensitive neurons is known to promote non-rem (nrem) sleep and inhibit neuronal discharge in arousal-related brain structures. the perifornical area of the lateral hypothalamus (pf/lh) was recently recognized to be an additional important arousal promoting region. we studied the behavior of pf/lh neurons in rats during the normal sleep-wake cycle and in response to local poa warming. most pf/lh neurons were wake-active, and exhibited low discharge throu ... | 2003 | 12505669 |
| brain structures and mechanisms involved in the generation of nrem sleep: focus on the preoptic hypothalamus. | four lines of research have greatly increased our understanding of the hypothalamic preoptic area (poa) sleep-promoting system. first, sleep-active neurons within the poa have been identified using both electrophysiological recording and immediate early gene protein (c-fos) staining methods. segregated sleep-active neurons were found in ventrolateral and median poa (vlpo and mnpn). additional sleep-active neurons may be intermixed with non-sleep specific neurons in other poa regions and the adja ... | 2001 | 12530996 |
| sleep and the hypothalamo-pituitary-adrenocortical system. | the intention of this review is to summarize the current knowledge on the bidirectional interaction between sleep eeg and the secretion of corticotropin (acth) and cortisol. the administration of various hypothalamic-pituitary- adrenocortical (hpa) hormones and their antagonists exerts specific sleep-eeg changes in several species including humans. it is well documented that corticotropin releasing hormone (crh) impairs sleep and enhances vigilance. in addition, it may promote rem sleep. changes ... | 2002 | 12531148 |
| activation of the phasic pontine-wave generator enhances improvement of learning performance: a mechanism for sleep-dependent plasticity. | the aim of this study was to test the hypothesis that supplementary activation of the phasic pontine wave (p-wave) generator during rapid eye movement (rem) sleep enhances consolidation and integration of memories, resulting in improved learning. to test this hypothesis, two groups of rats were trained on a two-way active avoidance learning task in the morning. immediately after training, one group of rats received a carbachol microinjection into the p-wave generator and the other group was micr ... | 2003 | 12542673 |
| glutamatergic afferent projections to the dorsal raphe nucleus of the rat. | based on wga-apo-hrp-gold (wg) retrograde tracing, the present study revealed that different subdivisions of the dorsal raphe (dr) such as dorsomedial, ventromedial, lateral wing, and caudal regions receive unique, topographically organized afferent inputs, that are more restricted than previously reported. phaseolus vulgaris leucoagglutinin anterograde tracing studies confirmed that the medial prefrontal cortex provides the major afferent input to each subdivision of the dr. double-labeling stu ... | 2003 | 12560111 |
| changes in the sleep-wake cycle architecture and cortical nitric oxide release during ageing in the rat. | changes in sleep-wake states and nitric oxide release were examined in aged rats versus young-adult ones. sleep-wake recordings and nitric oxide measurements were taken from animals chronically equipped with polygraphic and voltametric electrodes. animals were examined in baseline conditions and in response to a 24-hour paradoxical sleep deprivation. in aged rats, basal amount of paradoxical sleep is decreased during the light phase versus young-adult animals. after paradoxical sleep deprivation ... | 2003 | 12573725 |
| gabaa receptor antagonism at the hypoglossal motor nucleus increases genioglossus muscle activity in nrem but not rem sleep. | the pharyngeal muscles, such as the genioglossus (gg) muscle of the tongue, are important for effective lung ventilation since they maintain an open airspace. rapid-eye-movement (rem) sleep, however, recruits powerful neural mechanisms that can abolish gg activity, even during strong reflex respiratory stimulation by elevated co2. in vitro studies have demonstrated the presence of gabaa receptors on hypoglossal motoneurons, and these and other data have led to the speculation that gabaa mechanis ... | 2003 | 12611924 |
| episodic neonatal hypoxia evokes executive dysfunction and regionally specific alterations in markers of dopamine signaling. | perinatal ischemic-anoxic and prolonged anoxic insults lead to impaired dopaminergic signaling and are hypothesized to contribute, at least in part, to the pathogenesis of disorders of minimal brain dysfunction such as attention-deficit hyperactivity disorder. we hypothesized that subtle intermittent hypoxic insults, occurring during a period of critical brain development, are also pathogenic to dopaminergic signaling, thereby contributing to behavioral and executive dysfunction. between postnat ... | 2003 | 12614682 |
| modafinil increases histamine release in the anterior hypothalamus of rats. | modafinil, (rs)-2-(diphenylmethylsulfinyl)acetamide, is a well known wake promoting drug used for the treatment of narcolepsy. we investigated the effect of modafinil on the hypothalamic histamine release in the anesthetized rat using in vivo microdialysis. modafinil (150 mg/kg, i.p.) increased histamine release by 150% of the basal release. the intracerebroventricular (i.c.v.) injection of modafinil (1 nmol) also increased histamine release, however, when modafinil (1 nmol) was injected directl ... | 2003 | 12614915 |
| the wake-promoting hypocretin-orexin neurons are in an intrinsic state of membrane depolarization. | wakefulness depends on the activity of hypocretin-orexin neurons because their lesion results in narcolepsy. how these neurons maintain their activity to promote wakefulness is not known. here, by recording for the first time from hypocretin-orexin neurons and comparing their properties with those of neurons expressing melanin-concentrating hormone, we show that hypocretin-orexin neurons are in an intrinsic state of membrane depolarization that promotes their spontaneous activity. we propose tha ... | 2003 | 12629156 |
| enzymes of adenosine metabolism in the brain: diurnal rhythm and the effect of sleep deprivation. | adenosine plays a role in promoting sleep, an effect that is thought to be mediated in the basal forebrain. adenosine levels vary in this region with prolonged wakefulness in a unique way. the basis for this is unknown. we examined, in rats, the activity of the major metabolic enzymes for adenosine - adenosine deaminase, adenosine kinase, ecto- and cytosolic 5'-nucleotidase - in sleep/wake regulatory regions as well as cerebral cortex, and how the activity varies across the day and with sleep de ... | 2003 | 12675911 |
| effects of acoustic stimulation on cardiovascular regulation during sleep. | the interaction of wake-sleep states and acoustic stimulation on cardiovascular regulation was studied on rats implanted with electroencephalogram and electromyogram electrodes and an arterial catheter. mild acoustic stimuli (1000 hz, 90 db, 50-ms beeps) were administered during wakefulness (w), non-rapid eye movement (nrem) sleep and rem sleep and the changes induced in heart period (hp, ms) and mean arterial pressure (map, mmhg) were analyzed. two 30-s sequences of beat-to-beat hp and map valu ... | 2003 | 12683480 |
| vasoactive intestinal polypeptide and pituitary adenylate cyclase-activating polypeptide activate hyperpolarization-activated cationic current and depolarize thalamocortical neurons in vitro. | ascending pathways mediated by monoamine neurotransmitters regulate the firing mode of thalamocortical neurons and modulate the state of brain activity. we hypothesized that specific neuropeptides might have similar actions. the effects of vasoactive intestinal peptide (vip) and pituitary adenylate cyclase-activating polypeptide (pacap) were tested on thalamocortical neurons using whole-cell patch-clamp techniques applied to visualized neurons in rat brain slices. vip (2 microm) and pacap (100 n ... | 2003 | 12684461 |
| evidence implicating a role for orexin-1 receptor modulation of paradoxical sleep in the rat. | the neuropeptide orexin-a modulates the sleep-wake cycle such that central administration to rats increases arousal, reduces slow-wave-sleep (sws) and paradoxical sleep (ps) and delays ps onset. the contribution of orexin-1 and -2 receptor (oxr) activation to this orexin-a response is still unknown. using the ox(1)r antagonist sb-334867-a we investigated the role of this receptor in orexin-a-induced ps alteration. male rats prepared for frontal-occipital electroencephalograph, nuchal muscle elec ... | 2003 | 12697296 |
| additive wake-promoting actions of medial basal forebrain noradrenergic alpha1- and beta-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 in the medial septal (ms) and medial preoptic (mpoa) areas. mpoa alpha1-receptors exert similar wake-promoting actions. the current study examines the influence of alpha1-receptors located within ms on sleep-wake state. in addition, the extent to which alpha1- and beta-receptors located within ms and mpoa interac ... | 2003 | 12708531 |
| cell-selective effects of ammonia on glutamate transporter and receptor function in the mammalian brain. | increased brain ammonia concentrations are a hallmark feature of several neurological disorders including congenital urea cycle disorders, reye's syndrome and hepatic encephalopathy (he) associated with liver failure. over the last decade, increasing evidence suggests that hyperammonemia leads to alterations in the glutamatergic neurotransmitter system. studies utilizing in vivo and in vitro models of hyperammonemia reveal significant changes in brain glutamate levels, glutamate uptake and gluta ... | 2003 | 12742100 |
| inhibition of rostral basal forebrain neurons promotes wakefulness and induces fos in orexin neurons. | the present study examined whether the activities of the rostral basal forebrain neurons alter the activities of the orexin (also known as hypocretin) neurons in the tuberal part of the hypothalamus in rats. we performed microdialysis perfusion of the ventromedial portion of the rostral basal forebrain with the gabaa receptor agonist muscimol to inhibit focally the neuronal activities in the rostral basal forebrain. then, we monitored sleep/wake behaviour and investigated the pattern of activiti ... | 2003 | 12752381 |
| effect of sleep and sleep deprivation on serotonergic neurotransmission in the hippocampus: a combined in vivo microdialysis/eeg study in rats. | brainstem serotonergic neurotransmission is implicated in sleep regulation. however, the role of serotonin (5-ht) in forebrain regions in sleep-wake mechanisms is still unclear. here, we have investigated, using a combined in vivo microdialysis/electroencephalogram method, the relationship between hippocampal 5-ht levels and sleep-wake behaviour in the rat. a clear-cut relationship was found between hippocampal 5-ht levels and vigilance state. the highest levels of 5-ht were observed during wake ... | 2003 | 12752789 |
| a subpopulation of rats show social and sleep-waking changes typical of chronic neuropathic pain following peripheral nerve injury. | neuropathic conditions for which treatment is sought, the so-called chronic pain syndrome, are characterized usually by complex behavioural disturbances as well as pain. in this study we evaluated whether social behavioural and sleep disruptions occurred after nerve injury. before and after chronic constriction of the sciatic nerve, resident-intruder and sleep-wake cycles, as well as mechanical and thermal allodynia/hyperalgesia, were quantified. sciatic nerve injury in all animals reduced withd ... | 2003 | 12752790 |
| h3 agonist immepip markedly reduces cortical histamine release, but only weakly promotes sleep in the rat. | presynaptic h3 receptors exert negative control on brain histamine synthesis and release and may thereby play a key role in the control of the sleep/wake cycle. this suggests that pharmacological stimulation by h3 receptor agonists may potentially decrease wakefulness and induce sleep. this study reports the effect of a potent and selective h3 agonist, immepip, on eeg assessed sleep/wake phases in sprague-dawley rats at doses that significantly modulate brain histamine release. immepip injected ... | 2003 | 12798672 |
| is spontaneous high-voltage rhythmic spike discharge in long evans rats an absence-like seizure activity? | a distinct high-voltage rhythmic spike (hvrs) discharge characterized by a barrage of negative spikes oscillating at 5-12 hz was observed in chronically implanted long evans rats. spontaneous hvrs discharges were exhibited in 90% of 40 long evans rats and occurred during sudden arrest of ongoing behavior (immobility) with occasional facial/whisker twitching. however, the function of hvrs discharges in long evans rats remains inconclusive to date and has been associated with alpha tremor/mu rhyth ... | 2004 | 12826656 |
| colocalization of orexin a and glutamate immunoreactivity in axon terminals in the tuberomammillary nucleus in rats. | the orexins (also known as hypocretins) are peptide neurotransmitters made by hypothalamic neurons that are thought to play an important role in regulating wake-sleep states. one terminal area for orexin neurons is the tuberomammillary nucleus, a histaminergic cell group that is wake-active, but the relationship of the orexinergic terminals to the tuberomammillary neurons has not been examined in detail. we studied the ultrastructure of orexin a-immunoreactive axons and terminals in the tuberoma ... | 2003 | 12831862 |
| state-dependent activity of neurons in the perifornical hypothalamic area during sleep and waking. | neurons containing orexins are located in the perifornical hypothalamic area and are considered to have a role in sleep-wake regulation. to examine how this area is involved in the regulation of sleep and wakefulness, we recorded neuronal activity in undrugged, head-restrained rats across sleep-waking cycles. recordings were made in the perifornical hypothalamic area where orexin-immunoreactive neurons are distributed (pfh), and in the area dorsal to the pfh, including the zona incerta and subin ... | 2003 | 12831874 |
| intracerebral oxytocin modulates sleep-wake behaviour in male rats. | oxytocin released within the brain under basal conditions and in response to stress is differentially involved in the regulation of the hypothalamo-pituitary-adrenal (hpa) axis. because the hpa axis plays an important role in the regulation of wakefulness, central oxytocin may modulate sleep-wake behaviour. in the present vehicle-controlled study, we assessed the influence of a selective oxytocin receptor antagonist (des-gly-nh2d(ch2)5 [tyr(me)2,thr4] ovt; 0.75 microg/5 microl) or of synthetic o ... | 2003 | 12832103 |
| bidirectional interactions between antigen-bearing respiratory tract dendritic cells (dcs) and t cells precede the late phase reaction in experimental asthma: dc activation occurs in the airway mucosa but not in the lung parenchyma. | the airway mucosal response to allergen in asthma involves influx of activated t helper type 2 cells and eosinophils, transient airflow obstruction, and airways hyperresponsiveness (ahr). the mechanism(s) underlying transient t cell activation during this inflammatory response is unclear. we present evidence that this response is regulated via bidirectional interactions between airway mucosal dendritic cells (amdc) and t memory cells. after aerosol challenge, resident amdc acquire antigen and ra ... | 2003 | 12835476 |
| differential kinetics of hypocretins in the cerebrospinal fluid after intracerebroventricular administration in rats. | different potencies for hypocretin-1 and -2 in sleep-wake regulation and feeding after intracerebroventricular (icv) administration have been reported. these differences were often explained by the selectivity of the two hypocretins for hypocretin receptor-1 and -2, but little attention has been paid to kinetics of hypocretin peptides. we investigated the kinetics of the icv hypocretin-1 and -2 in rats. icv hypocretin-1 (10 nmol) increased hypocretin-1 peptide level in the csf by 800-fold from b ... | 2003 | 12853114 |
| the suprachiasmatic nucleus balances sympathetic and parasympathetic output to peripheral organs through separate preautonomic neurons. | opposing parasympathetic and sympathetic signals determine the autonomic output of the brain to the body and the change in balance over the sleep-wake cycle. the suprachiasmatic nucleus (scn) organizes the activity/inactivity cycle and the behaviors that go along with it, but it is unclear how the hypothalamus, in particular the scn, with its high daytime electrical activity, influences this differentiated autonomic balance. in a first series of experiments, we visualized hypothalamic pre-sympat ... | 2003 | 12866127 |
| contribution of twik-related acid-sensitive k+ channel 1 (task1) and task3 channels to the control of activity modes in thalamocortical neurons. | the thalamocortical network is characterized by rhythmic burst activity during natural sleep and tonic single-spike activity during wakefulness. the change between these two activity modes is partially governed by transmitters acting on leak k+ currents in the thalamus, although the nature of the constituting ion channels is not yet known. in the present study, the contribution of members of the two-pore domain k+ channel family to the leak current was investigated using whole-cell patch-clamp t ... | 2003 | 12878686 |
| [morphological characteristics of spermatogenesis in experimental juvenile hypothyroidism in rats]. | partisular features have been studied of spermatozoa and cells of spermatogenesis in rats in experimental hypothyroidism in the prepubertal period. common features to be seen in the wake of hypothyroidism include a decline in the locomotor activity of spermatozoa and abnormalities in maturation of cells of spermatogenesis, which facts necessitate restoration of the thyroid function to prevent disorders of spermatogenesis in the fully-developed organism. | 2003 | 12889374 |
| ethanol influences on native t-type calcium current in thalamic sleep circuitry. | ethanol is known to disrupt normal sleep rhythms; however, the cellular basis for this influence is unknown. this study uses an in vitro slice preparation coupled with electrophysiological recordings to probe neuronal responses to acute ethanol exposure. recordings were conducted in ferret and rat thalamic slices, since thalamic circuitry is an integral component of sleep/wake cycles and sleep spindles. a key mediator of spindle wave activity is the low-threshold calcium current (t-type current) ... | 2003 | 12893844 |
| a broad role for melanopsin in nonvisual photoreception. | the rod and cone photoreceptors that mediate visual phototransduction in mammals are not required for light-induced circadian entrainment, negative masking of locomotor activity, suppression of pineal melatonin, or the pupillary light reflex. the photopigment melanopsin has recently been identified in intrinsically photosensitive retinal ganglion cells (rgcs) that project to the suprachiasmatic nucleus (scn), intergeniculate leaflet (igl), and olivary pretectal nucleus, suggesting that melanopsi ... | 2003 | 12904470 |
| alpha 2 adrenergic receptors on gabaergic, putative sleep-promoting basal forebrain neurons. | the basal forebrain plays an important role in the modulation of cortical activity and sleep-wake states. yet its role must be multivalent as lesions reportedly diminish cortical fast activity and also cortical slow activity along with slow wave sleep (sws). basal forebrain cholinergic vs. gabaergic cell groups could differentially influence these processes. by labelling recorded neurons with neurobiotin (nb) using the juxtacellular technique and identifying them by immunostaining, we previously ... | 2003 | 12911769 |
| dynamic changes of gamma activities of somatic cortical evoked potentials during wake-sleep states in rats. | somatic evoked potentials (seps) from three brain sites elicited by electrical stimulation in 10 rats were recorded throughout wake-sleep states with intrinsic changes in temporal architectures under different vigilance states. based on the patterns of spontaneous brain and muscle activities, three characteristic vigilance states could be classified: awake, slow-wave sleep (sws), and paradoxical sleep (ps). spontaneous gamma activities prominently appeared under awake and ps states, but less und ... | 2003 | 12914976 |
| cellular interactions in the rat somatosensory thalamocortical system during normal and epileptic 5-9 hz oscillations. | in genetic absence epilepsy rats from strasbourg (gaers), generalized spike-and-wave (sw) discharges (5-9 sw s(-1)) develop during quiet immobile wakefulness from a natural, medium-voltage, 5-9 hz rhythm. this study examines the spatio-temporal dynamics of cellular interactions in the somatosensory thalamocortical system underlying the generation of normal and epileptic 5-9 hz oscillations. paired single-unit and multi-unit recordings between the principal elements of this circuit and intracellu ... | 2003 | 12923213 |
| effects of passive-avoidance training on sleep-wake state-specific activity in the basolateral and central nuclei of the amygdala. | this study examined the effects of intense emotional learning on the sleep-wake state-specific electroencephalographic (eeg) activities of the basolateral (bla) and central (cea) nuclei of the amygdala. rats were trained on a passive-avoidance learning (pal) protocol that was followed by 6 hr of undisturbed polygraphic recording and a pal test. after pal training, the total amount of rem sleep decreased: high-frequency eeg power decreased in the cea during rem sleep and increased in the bla duri ... | 2003 | 12931960 |
| role of inhibitory amino acids in control of hypoglossal motor outflow to genioglossus muscle in naturally sleeping rats. | the hypoglossal motor nucleus innervates the genioglossus (gg) muscle of the tongue, a muscle that helps maintain an open airway for effective breathing. rapid-eye-movement (rem) sleep, however, recruits powerful neural mechanisms that can abolish gg activity even during strong reflex stimulation such as by hypercapnia, effects that can predispose to sleep-related breathing problems in humans. we have developed an animal model to chronically manipulate neurotransmission at the hypoglossal motor ... | 2003 | 12937280 |
| wake-promoting actions of dopamine d1 and d2 receptor stimulation. | multiple ascending neurotransmitter systems participate in the regulation of behavioral state. for example, noradrenergic, cholinergic, and serotonergic systems increase eeg and, in some cases, behavioral indices of arousal. the extent to which dopaminergic systems exert a similar activating influence on behavioral state remains unclear. the current studies examined the wake-promoting actions of centrally administered d1 and d2 receptor agonists. in these studies, intracerebroventricular infusio ... | 2003 | 12944496 |
| fos immunoreactivity in hypocretin-synthesizing and hypocretin-1 receptor-expressing neurons: effects of diurnal and nocturnal spontaneous waking, stress and hypocretin-1 administration. | hypocretin/orexin modulates sleep-wake state via actions across multiple terminal fields. within waking, hypocretin may also participate in high-arousal processes, including those associated with stress. the current studies examined the extent to which alterations in neuronal activity, as measured by fos immunoreactivity, occur within both hypocretin-synthesizing and hypocretin-1 receptor-expressing neurons across varying behavioral state/environmental conditions associated with varying levels o ... | 2003 | 12946712 |
| electrophysiological findings in the sprague-dawley rat induced by moderate-dose carboplatin. | carboplatin is a second generation platinum-containing anti-tumor drug which selectively alters the micromechanical function of the inner hair cells (ihcs) of the organ of corti in the chinchilla. data from a recent study [wake et al., acta otolaryngol. 116 (1996) 374-381], using the chinchilla model, have suggested that a moderate dose of carboplatin alters the efferent feedback loop gain of the ohcs. the present study was designed to evaluate the possible 'efferent feedback alteration mechanis ... | 2003 | 12948601 |
| interleukin-1beta enhances non-rapid eye movement sleep when microinjected into the dorsal raphe nucleus and inhibits serotonergic neurons in vitro. | interleukin-1 (il-1) and il-1 receptors are constitutively expressed in normal brain. il-1 increases non-rapid eye movements (nrem) sleep in several animal species, an effect mediated in part by interactions with the serotonergic system. the site(s) in brain at which interactions between il-1 and the serotonergic system increase nrem sleep remain to be identified. the dorsal raphe (drn) is the origin of the major ascending serotonergic pathways to the forebrain, and it contains il-1 receptors. t ... | 2003 | 12956704 |
| sleep-wake mechanisms and basal forebrain circuitry. | the seminal studies by von economo in humans (1) and by nauta (2) in rats implicated specific basal forebrain areas at the preoptic level as important in sleep regulation. in the last two decades, studies employing recording of single neurons and monitoring of sleep parameters with subsequent chemical and electron microscopic identification of the synaptic input-output relations of these recorded neurons, provided an increasingly detailed understanding of the function of specific neurotransmitte ... | 2003 | 12957822 |
| a role of melanin-concentrating hormone producing neurons in the central regulation of paradoxical sleep. | peptidergic neurons containing the melanin-concentrating hormone (mch) and the hypocretins (or orexins) are intermingled in the zona incerta, perifornical nucleus and lateral hypothalamic area. both types of neurons have been implicated in the integrated regulation of energy homeostasis and body weight. hypocretin neurons have also been involved in sleep-wake regulation and narcolepsy. we therefore sought to determine whether hypocretin and mch neurons express fos in association with enhanced pa ... | 2003 | 12964948 |
| indirect projections from the suprachiasmatic nucleus to the median preoptic nucleus in rat. | we recently showed, using dual tract-tracing, that the suprachiasmatic nucleus (scn), the site of the principal circadian clock in mammals, may have indirect projections to the sleep-promoting ventrolateral preoptic nucleus (vlpo) via relays in the medial preoptic area (mpa), dorsomedial hypothalamic nucleus (dmh), and, to a lesser extent, the subparaventricular zone (spvz). here, we found that the injection of the rostral mpa, the periventricular nucleus/medial spvz, and the caudal dmh with a m ... | 2003 | 14499951 |
| artificial neural network detects changes in electro-encephalogram power spectrum of different sleep-wake states in an animal model of heat stress. | an effective application is presented of a back-propagation artificial neural network (ann) in differentiating electro-encephalogram (eeg) power spectra of stressed and normal rats in three sleep-wakefulness stages. the rats were divided into three groups, one subjected to acute heat stress, one subjected to chronic heat stress and one a handling control group. the polygraphic sleep recordings were performed by simultaneous recording of cortical eeg, electro-oculogram (eog) and electromyogram (e ... | 2003 | 14572011 |
| automated sleep staging in rat with a standard spreadsheet. | a new method of automated sleep-wake staging in the rat is described. hippocampal electroencephalographic (hpc) and nuchal electromyographic signals were recorded by a digital polygraph. the hpc channel was filtered off-line to obtain the original plus theta and delta waves. statistics of each of these four channels were obtained every 5 s and exported to a standard spreadsheet. the automated staging consisted of five steps: (1) automatic detection of waking, nonrapid eye movement sleep and rapi ... | 2003 | 14583408 |
| ozone exposure alters 5-hydroxy-indole-acetic acid contents in dialysates from dorsal raphe and medial preoptic area in freely moving rats. relationships with simultaneous sleep disturbances. | ozone (o3) has been reported to affect sleep patterns and also striatal and mesencephalic contents of 5-hydroxy-indole-acetic acid (5-hiaa) in rats. the aim of this work was to elucidate the effects of o3 exposure in rats upon extracellular 5-hiaa levels in the dorsal raphe (dr) and the hypothalamic medial preoptic area (mpo), two structures involved in sleep-wake homeostasis. exposure to o3 followed a bell-shaped diurnal pattern, similar to that observed in cities with high air pollution levels ... | 2003 | 14597128 |
| wake-related activity of tuberomammillary neurons in rats. | histaminergic neurons of the tuberomammillary nucleus (tmn) are hypothesized to promote wakefulness, but little is known about the activity of these cells during spontaneous behavior. we measured histaminergic neuron activity in the dorsomedial, ventrolateral, and caudal tmn at four different times using fos and adenosine deaminase immunohistochemistry and recordings of sleep/wake behavior. because circadian factors could influence neuronal activity, we then assessed tmn neuron activity in predo ... | 2003 | 14625060 |
| six-hour selective rem sleep deprivation increases the expression of the galanin gene in the hypothalamus of rats. | the effect of short-term selective rem sleep deprivation (rsd) on the gene expression of galanin in the rat hypothalamus was examined using in situ hybridization histochemistry. monitoring an electroencephalogram (eeg) and electromyogram (emg) on an on-line computer screen, as the rsd rats entered rem sleep, they were gently stroked on their backs using a brush to wake them during the rsd period. galanin mrna levels in the preoptic area (poa) were significantly increased by rsd for a period of 6 ... | 2003 | 14625082 |
| critical role of dorsomedial hypothalamic nucleus in a wide range of behavioral circadian rhythms. | the suprachiasmatic nucleus (scn) contains the brain's circadian pacemaker, but mechanisms by which it controls circadian rhythms of sleep and related behaviors are poorly understood. previous anatomic evidence has implicated the dorsomedial hypothalamic nucleus (dmh) in circadian control of sleep, but this hypothesis remains untested. we now show that excitotoxic lesions of the dmh reduce circadian rhythms of wakefulness, feeding, locomotor activity, and serum corticosteroid levels by 78-89% wh ... | 2003 | 14627654 |
| sleep-related sympathovagal imbalance in shr. | the role of the autonomic nervous system in spontaneous hypertension during each stage of the sleep-wake cycle remains unclear. the present study attempted to evaluate the differences in cardiac autonomic modulations among spontaneously hypertensive rats (shr), normotensive wistar-kyoto rats (wky), and sprague-dawley rats (sd) across sleep-wake cycles. continuous power spectral analysis of electroencephalogram, electromyogram, and heart rate variability was performed in unanesthetized free movin ... | 2004 | 14630638 |
| activity of the hypothalamic-pituitary-adrenocortical system and sleep-wake cycle in rats with acute systemic inflammation. | activity of the hypothalamic-pituitary-adrenocortical system and eeg characteristics of the sleep-wake cycle were studied on adult male wistar rats with acute inflammation produced by bacterial lipopolysaccharide in a dose of 250 microg/100 g body weight. blood concentrations of adrenocorticotropic hormone and corticosterone increased by 6 and 10 times, respectively, 30 min after lipopolysaccharide administration and peaked 2 hours after challenge. in this period the sleep-wake cycle underwent t ... | 2003 | 14631484 |
| short-term sleep disturbance enhances brain-derived neurotrophic factor gene expression in rat hippocampus by acting as internal stressor. | rats were subjected to nonselective sleep disturbance for short periods under conditions designed to minimize the adverse influence of external stresses, such as environmental conditions and restricted movement, and both brain-derived neurotrophic factor (bdnf) protein and its mrna levels in the brain were then determined to investigate the influence of sleep disturbance itself on bdnf gene expression. total sleep duration was partially but significantly reduced by disturbing the sleep/wake cycl ... | 2003 | 14645989 |
| brain capillary perfusion in the spontaneously hypertensive rat during the wake-sleep cycle. | hypertension is accompanied by circulatory changes in the brain and in other vascular districts; at disease onset, these changes may be largely functional and dependent on metabolic and vegetative drives. the wake-sleep cycle is a major physiological source of ultradian variability in autonomic function and in cerebral blood flow and metabolism. aim of the study was to investigate whether sleep induces functional changes in the brain microcirculation in the developing hypertensive state. the fra ... | 2004 | 14661067 |
| a corticotropin-releasing hormone antisense oligodeoxynucleotide reduces spontaneous waking in the rat. | we have previously hypothesized that corticotropin-releasing hormone (crh) is involved in the regulation of physiological waking. in this study, we tested the hypothesis that reduction of crh peptide would reduce spontaneous wakefulness of rats. we administered intracerebroventricularly into rats at several circadian time points antisense or sense dna oligodeoxynucleotides (odns) corresponding to the initiation codon of crh mrna and determined subsequent effects on wakefulness and sleep of the r ... | 2004 | 14687700 |
| the presence of tata-binding protein in the brainstem, correlated with sleep apnea in sids victims. | recent reports have indicated that the presence of transcription factors and rna polymerase decreases in rat brains that suffer perinatal asphyxia from hypoxia. as hypoxia has been proposed as a causative factor in the sudden infant death syndrome (sids), the correlation between tata-binding protein (tbp) in the brainstem of sids victims as a marker of transcription and the incidence of sleep apnea was investigated. | 2003 | 14693397 |
| the diurnal rhythm of adenosine levels in the basal forebrain of young and old rats. | there are significant decrements in sleep with age. these include fragmentation of sleep, increased wake time, decrease in the length of sleep bouts, decrease in the amplitude of the diurnal rhythm of sleep, decrease in rapid eye movement sleep and a profound decrease in electroencephalogram delta power (0.3-4 hz). old rats also have less sleep in response to 12 h-prolonged wakefulness (w) indicating a reduction in sleep drive with age. the mechanism contributing to the decline in sleep with agi ... | 2004 | 14698744 |
| hypothalamic contribution to sleep-wake cycle development. | infant mammals cycle rapidly between sleep and wakefulness and only gradually does a more consolidated sleep pattern develop. the neural substrates responsible for this consolidation are unknown. to establish a reliable measure of sleep-wake cyclicity in infant rats, nuchal muscle tone was measured in 2-, 5-, and 8-day-old rats, as were motor behaviors associated with sleep (i.e. myoclonic twitching) and wakefulness (e.g. kicking, stretching). sleep-wake cycles of 2-day-old rats were characteriz ... | 2004 | 14698764 |
| nicotinic enhancement of the noradrenergic inhibition of sleep-promoting neurons in the ventrolateral preoptic area. | according to multiple lines of evidence, neurons in the ventrolateral preoptic area (vlpo) that contain gaba promote sleep by inhibiting neurons of the arousal systems. reciprocally, transmitters used by these systems, including acetylcholine (ach) and noradrenaline (na), exert an inhibitory action on the vlpo neurons. because nicotine, an agonist of ach, acts as a potent stimulant, we queried whether it might participate in the cholinergic inhibition of these sleep-promoting cells. indeed, we f ... | 2004 | 14715938 |
| immunological inhibition of carcinogenesis. | the combination of new information provided by fundamental immunology, along with the refinement of genetic engineering techniques has given scientists the capacity to produce vaccines able to inhibit the growth of most if not every transplantable tumor. however, when faced with already established tumors, vaccines fail to afford any significant protection. many studies are underway which seek to overcome this gloomy situation. however, another possibility is to follow the indications provided b ... | 2004 | 14722672 |
| medullary serotonergic neurones and adjacent neurones that express neurokinin-1 receptors are both involved in chemoreception in vivo. | neurokinin-1 receptor (nk1r)-expressing neurones that are involved in chemoreception at the retrotrapezoid nucleus (nattie & li, 2002b) are also prominent at locations that contain medullary serotonergic neurones, which are chemosensitive in vitro. in medullary regions containing both types, we evaluated their role in central chemoreception by specific cell killing. we injected (2 x 100 nl) (a) substance p-saporin (sp-sap; 1 microm) to kill nk1r-expressing neurones, (b) a novel conjugate of a mo ... | 2004 | 14724193 |
| instrumental rem sleep deprivation in neonates leads to adult depression-like behaviors in rats. | previous studies have demonstrated that neonatal suppression of rapid eye movement (rem) sleep by pharmacologic agents, particularly clomipramine, produces adult depressive behavior. these findings suggest the hypothesis that rem sleep deprivation (rsd) mediates the depressogenic behaviors of neonatally administered antidepressant drugs. drug suppression of rsd, however, was thought to be confounded by the other effects of the drugs. the current study was aimed to show the adult effect of neonat ... | 2003 | 14746380 |
| microinjection of the nitric oxide synthase inhibitor l-name into the lateral basal forebrain alters the sleep/wake cycle of the rat. | the effects of n(g)-nitro-l-arginine methyl ester (l-name) (0.19-0.74 micromol), a competitive inhibitor of the enzyme nitric oxide synthase (nos); l-arginine (48.0-191.0 nmol), a nitric oxide (no) precursor; and molsidomine (0.06-0.24 nmol), an no donor, on spontaneous sleep were studied in adult rats implanted for chronic sleep recordings. direct bilateral application of l-name into the nucleus of the horizontal limb of the diagonal band of broca (hdb) increased waking (w) and reduced slow wav ... | 2004 | 14751418 |
| design and validation of a computer-based sleep-scoring algorithm. | a computer-based sleep scoring algorithm was devised for the real time scoring of sleep-wake state in wistar rats. electroencephalogram (eeg) amplitude (microv(rms)) was measured in the following frequency bands: delta (delta; 1.5-6 hz), theta (theta; 6-10 hz), alpha (alpha; 10.5-15 hz), beta (beta; 22-30 hz), and gamma (gamma; 35-45 hz). electromyographic (emg) signals (microv(rms)) were recorded from the levator auris longus (neck) muscle, as this yielded a significantly higher algorithm accur ... | 2004 | 14757347 |
| target areas innervated by pacap-immunoreactive retinal ganglion cells. | the retinohypothalamic tract (rht) originates from a subset of retinal ganglion cells (rgcs). the cells of the rht co-store the neurotransmitters pacap and glutamate, which in a complex interplay mediate light information to the circadian clock located in the suprachiasmatic nuclei (scn). these ganglion cells are intrinsically photosensitive probably due to expression of melanopsin, a putative photoreceptor involved in light entrainment. in the present study we examined pacap-containing retinal ... | 2004 | 14991397 |
| effect of the wake-promoting agent modafinil on sleep-promoting neurons from the ventrolateral preoptic nucleus: an in vitro pharmacologic study. | the pharmacologic profile of modafinil, an increasingly popular wake-promoting drug for narcolepsy treatment, differs from those of classic psychostimulants such as amphetamine. however, its brain targets are still a matter of debate. we hypothesized that modafinil could increase waking by inhibiting the sleep-promoting neurons from the ventrolateral preoptic nucleus (vlpo). such action could be direct or indirect via the potentiation of inhibition mediated by waking neurotransmitters. we thus s ... | 2004 | 14998233 |
| twenty-four-hour disruption of the sleep-wake cycle and sleep-onset rem-like episodes in a rat model of african trypanosomiasis. | patients with human african trypanosomiasis (sleeping sickness) due to the inoculation of trypanosoma brucei gambiense or rhodesiense show a major disruption of the 24-hour sleep-wake distribution, accompanied by the occurrence of sleep-onset rapid-eye-movement (rem) sleep episodes, proportional to the severity of the illness. although animal models of human african trypanosomiasis have been developed to understand the pathogenic mechanisms leading to immune alterations, the development of an an ... | 2004 | 14998236 |
| nicotine dependence and psychiatric disorders. | nicotine addiction is the single largest preventable cause of morbidity and mortality in the western world. smoking is not any more just a bad habit, but a substance addiction problem. the pharmacological aspects of nicotine show that this substance has a broad distribution in the different body compartnents, due mainly to its lipophilic characteristic. there are nicotinic receptors as members of cholinergic receptors' family. they are located in neuromuscular junction and in the central nervous ... | 2003 | 15011738 |
| sleep-wake related discharge properties of basal forebrain neurons recorded with micropipettes in head-fixed rats. | the basal forebrain has been shown to play an important role in cortical activation of wake and paradoxical sleep (ps), yet has also been posited to play a role in slow wave sleep (sws). in an effort to determine whether these different roles may be fulfilled by different cell groups, including cholinergic and gabaergic cells, we recorded from 123 units in waking-sleeping, head-fixed rats using micropipettes to allow juxtacellular labeling. functional sets of intermingled cell groups emerged as ... | 2004 | 15028746 |
| sleep deprivation increases the activation of nuclear factor kappa b in lateral hypothalamic cells. | sleep deprivation increases sleep propensity in rats and mice as well as the production of several sleep-regulatory substances. nuclear factor kappa b (nf-kappa b) is a transcription factor implicated in the activation of many of these sleep-promoting substances. a unique population of neurons immunoreactive for the p65 subunit of nf-kappa b was previously localized within the caudal dorsolateral hypothalamus of rats. therefore, we evaluated the effect of sleep deprivation on nf-kappa bp65-immun ... | 2004 | 15033423 |
| hypocretin/orexin innervation and excitation of identified septohippocampal cholinergic neurons. | hypothalamic fibers containing the wake-promoting peptides, hypocretins (hcrts) or orexins, provide a dense innervation to the medial septum-diagonal band of broca (msdb), a sleep-associated brain region that has been suggested to show intense axonal degeneration in canine narcoleptics. the msdb, via its cholinergic and gabaergic projections to the hippocampus, controls the hippocampal theta rhythm and associated learning and memory functions. neurons of the msdb express very high levels of the ... | 2004 | 15071100 |
| clozapine alters sleep-wake behavior in rats. | clozapine is an atypical antipsychotic agent showing therapeutic efficacy superior to that of classical neuroleptics. clozapine has strong sedative effects, but detailed studies on the drug influencing sleep in rodents are lacking. we studied the effects of clozapine on sleep and body temperature in rats. clozapine (0, 2.5, and 7.5 mg/kg) was given i.p. to male wistar rats at the beginning of the rest period. after administration of 7.5 mg/kg clozapine, animals were significantly more awake duri ... | 2004 | 15085087 |
| kindling stimuli delivered at different times in the sleep-wake cycle. | clinical and experimental observations argue that sleep disturbances are common and coexist in patients with epilepsy. our previous observations have suggested that neural-immune interactions between corticotropin-releasing hormone (crh) and interleukin-1 (il-1) are involved in the regulation of physiological sleep-wake behavior. in the present study, we determined the involvement of crh and il-1 in the alteration of sleep-wake activities in rats when amygdala kindling was given either at the be ... | 2004 | 15124712 |
| sleep-wake states and cortical synchronization control by pregnenolone sulfate into the pedunculopontine nucleus. | cholinergic neurons of the pedunculopontine tegmentum nucleus (ppt) are crucial for initiation and maintenance of electroencephalographic (eeg) desynchronization states like paradoxical sleep and wakefulness. these neurons are regulated by classical neurotransmitter systems from the pontomesencephalic reticular formation and basal ganglia. in addition to this regulation, ppt neuron activity could be modulated by endogenous neurosteroids and particularly by pregnenolone sulfate (preg-s) because s ... | 2004 | 15139033 |
| experimentally gained insight - based proposal apropos the treatment of osteonecrosis of the femoral head. | an impeded blood flow through the femoral head is incriminated in the etiopathogenesis of osteonecrosis of the femoral head. the disorder is either primary (idiopathic avascular osteonecrosis) or secondary to one condition or another, say, corticosteroid medication, fracture of the neck, coagulation defects, physical or thermal damage, storage disorders, alcoholism, and infectious, autoimmune as also marrow infiltrating diseases. in the wake of the necrosis, several mediators are released in inc ... | 2004 | 15142657 |
| effects of hypocretin2-saporin and antidopamine-beta-hydroxylase-saporin neurotoxic lesions of the dorsolateral pons on sleep and muscle tone. | the hypocretin neurons have been implicated in regulating sleep-wake states as they are lost in patients with the sleep disorder narcolepsy. hypocretin (hcrt) neurons are located only in the perifornical region of the posterior hypothalamus and heavily innervate pontine brainstem neurons, such as the locus coeruleus (lc), which have traditionally been implicated in promoting arousal. it is not known how the hypocretin innervation of the pons regulates sleep-wake states as pontine lesions have ne ... | 2004 | 15147308 |
| sleep, but not febrile responses of fisher 344 rats to immune challenge are affected by aging. | sleep is altered in response to infection and immune challenge in humans and non-human animals. although there are changes in sleep and facets of immune function with aging, sleep responses of aged subjects to immune challenge have received little, if any attention. to test the hypothesis that aging affects sleep responses to immune challenge, intracerebroventricular injections of interleukin 1 (il-1) were given to young and aged rats and subsequent sleep-wake behavior was determined. under basa ... | 2004 | 15157957 |
| pontine intertrigeminal region attenuates sleep apneas in rats. | to determine whether the pontine intertrigeminal region (itr), with recently described anatomic connections and an effect on vagally induced reflex apnea, has an impact on spontaneous sleep apneas in rats. | 2004 | 15164888 |
| changes in sleep patterns in spontaneously hypertensive rats. | to explore whether spontaneous hypertension is associated with a change in sleep pattern in rats. | 2004 | 15164892 |
| electro-encephalogram disturbances in different sleep-wake states following exposure to high environmental heat. | in this study, cerebral electrical activity or electro-encephalogram (eeg) was studied following exposure to high environmental heat, in three different age groups of freely moving rats. each age group was subdivided into three groups: the acute heat stress group, subjected to a single exposure of 4 h at 38 degrees c in the biological oxygen demand incubator; the chronic heat stress group, exposed for 21 days, for 1 h each day, at 38 degrees c in the incubator; and the handling control group. th ... | 2004 | 15191071 |
| acute shifts in baroreflex control of renal sympathetic nerve activity induced by rem sleep and grooming in rats. | the present study aimed to determine the impact of rem sleep and grooming on the baroreflex stimulus-response curve for renal sympathetic nerve activity (rsna). at least 3 days before study, wistar female rats (n= 12) were chronically implanted with catheters to measure systemic arterial pressure (p(a)) and to intravenously infuse vasoactive drugs. in addition, electrodes were placed for measurements of rsna, electroencephalogram, trapezius electromyogram and electrocardiogram. the baroreflex cu ... | 2004 | 15194739 |