Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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-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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| sleep-waking discharge patterns of median preoptic nucleus neurons in rats. | several lines of evidence show that the preoptic area (poa) of the hypothalamus is critically implicated in the regulation of sleep. functionally heterogeneous cell groups with sleep-related discharge patterns are located both in the medial and lateral poa. recently a cluster of neurons showing sleep-related c-fos immunoreactivity was found in the median preoptic nucleus (mnpn). to determine the specificity of the state-related behaviour of mnpn neurons we have undertaken the first study of thei ... | 2002 | 12205198 |
| tonic rhythmic activity of rat cerebellar neurons. | simultaneous recordings of multiple single unit activity in both cerebral and cerebellar cortex, cortical eeg, and both nuchal and vibrissal emg were obtained in nine unrestrained rats. putative purkinje cells of the deep vermal cerebellar cortex exhibited rhythmic discharge of simple spikes with extremely low variability in interspike intervals for several hours. the highly rhythmic nature of spike discharge was remarkably stable across all states of sleep (both slow-wave and rapid eye movement ... | 2002 | 12195529 |
| lactate in the brain of the freely moving rat: voltammetric monitoring of the changes related to the sleep-wake states. | cortical lactate was monitored voltammetrically in freely moving rats equipped with polygraphic electrodes. differential normal pulse voltammetric measurements were carried out using a lactate biosensor coated with lactate oxidase and cellulose acetate. changes occurring in lactate level were in keeping with sleep-wake states. during slow wave sleep (sws), the lactate level decreased significantly (-16.2%) vs. the spontaneous waking state (w) referenced to as 100%. during paradoxical sleep (ps), ... | 2002 | 12193189 |
| eeg measurements by means of radiotelemetry after intracerebroventricular (icv) cannulation in rodents. | the utility of implanted radiotelemetry transmitters for the measurement of electroencephalogram (eeg), locomotor activity, body temperature and cardiovascular parameters has been well documented. this paper focuses on the methodology, of combining radiotelemetry with intracerebroventricular (icv) cannulation. the two excitatory neuropeptides, orexin-a and orexin-b, can only be given by icv injection, therefore we examined their effects on the normal sleep-wake cycle of rodents in the present st ... | 2002 | 12191761 |
| a low-noise flexible integrated system for recording and analysis of multiple electrical signals during sleep-wake states in rats. | a low-noise flexible system for the simultaneous recording and analysis of several electrical signals (eeg, ecg, emg, and diaphragm emg) from the same rat was constructed for studying changes in physiological functions during the sleep-wake cycle. the hardware in the system includes a multichannel amplifier, a video camera, a timer code generator, and a pc. a miniature buffer headstage with high-input impedance connected to a 6-channel amplifier was developed. all electrical activities devoid of ... | 2002 | 12191760 |
| the crh1 receptor antagonist r121919 attenuates stress-elicited sleep disturbances in rats, particularly in those with high innate anxiety. | excessive corticotropin-releasing hormone (crh) secretion in limbic and prefrontal brain areas has been postulated to underly stress-related clinical conditions. studies in mice with deleted or pharmacologically compromised crh type 1 receptors (crh-r1) point to a key role of the crh/crh-r1 signaling cascade as a potential drug target. therefore, we compared the effect of a selective high affinity crh-r1 antagonist (r121919) on sleep-wake behavior in two rat lines selectively bred for either hig ... | 2002 | 12191624 |
| the physiology and pharmacology of the orexins. | orexin-a and orexin-b are two peptides derived by proteolytic cleavage from a 130 amino acid precursor prepro-orexin, which recently were isolated from the rat hypothalamus. orexin-a is fully conserved across mammalian species, whilst rat and human orexin-b differ by 2 amino acids. these peptides bind to two g(q)-coupled receptors, termed ox(1) and ox(2). the receptors are 64% homologous and highly conserved across species. orexin-a is equipotent at ox(1) and ox(2), whilst orexin-b displays mode ... | 2002 | 12191593 |
| melatonin microinjection into the medial preoptic area increases sleep in the rat. | a wide variety of hypnotic compounds including triazolam, pentobarbital, ethanol and adenosine have been reported to enhance sleep when microinjected into the medial preoptic area (mpa) of the anterior hypothalamus of the rat. it is uncertain whether the pineal hormone melatonin, which may alter sleep/wake physiology in mammals, acts at this site. a previous report has indicated that a more widespread injection of melatonin into the hypothalamus of the cat induces sleep. in the present study we ... | 2002 | 12175899 |
| eeg spectra, behavioral states and motor activity in rats exposed to acetylcholinesterase inhibitor chlorpyrifos. | exposure to organophosphates (op) has been associated with sleep disorders such as insomnia and "excessive dreaming." the central mechanisms of these effects are not well understood. ops inhibit acetylcholinesterase (ache) activity, leading to a hyperactivity of the brain cholinergic systems that are involved in sleep regulation. we studied alterations in the eeg, behavioral states, motor activity and core temperature in rats orally administered with 10 or 40 mg/kg of the op insecticide chlorpyr ... | 2002 | 12175464 |
| modulation of hypothalamic hypocretin/orexin mrna expression by glucocorticoids. | the orexins are peptides which were recently isolated from the rat hypothlamus. they play a role in energy homeostasis and regulation of feeding as well as in other functions such as the sleep-wake cycle. the involvement of glucocorticoids in stress processes as well as in body weight regulation is well known. in the present paper, we investigated the role of glucocorticoids on hypocretin (hcrt)/orexin (ox) pathway in sprague-dawley rats. we confirmed by in situ hybridization that prepro-hcrt/ox ... | 2002 | 12147238 |
| novel object presentation affects sleep-wake behavior in rats. | sleep is suggested to be crucial for the processing and storage of new information. several learning tasks have been shown to increase the amount of rapid eye movement sleep (rems) with its typical theta activity (6-8 hz) relative to total sleep time. vice versa, rems deprivation is able to affect memory consolidation following some, but not all learning tasks. furthermore, recent studies have shown an increase of spindle activity (12-15 hz) within the electroencephalogram (eeg) of nonrems as we ... | 2002 | 12123855 |
| orexins in rat dorsal motor nucleus of the vagus potently stimulate gastric motor function. | orexins regulate food intake, arousal, and the sleep-wake cycle. they are synthesized by neurons in the lateral hypothalamus and project to autonomic areas in the hindbrain. orexin a applied to the dorsal surface of the medulla stimulates gastric acid secretion via a vagally mediated pathway. we tested the hypothesis that orexins in the dorsal motor nucleus (dmn) of the vagus regulate gastric motor function. multibarelled micropipette assemblies were used to administer vehicle, l-glutamate, orex ... | 2002 | 12121895 |
| role of corticotropin-releasing hormone in stressor-induced alterations of sleep in rat. | corticotropin-releasing hormone (crh) mediates responses to a variety of stressors. we subjected rats to a 1-h period of an acute stressor, physical restraint, and determined the impact on subsequent sleep-wake behavior. restraint at the beginning of the light period, but not the dark period, increased waking and reduced rapid eye movement sleep without dramatically altering slow-wave sleep (sws). electroencephalogram (eeg) slow-wave activity during sws and brain temperature were increased by th ... | 2002 | 12121853 |
| theoretical and practical considerations in the application of whole body plethysmography to sleep research. | the sleep-wake state has a profound influence on many, perhaps most, aspects of normal physiology and is strongly implicated in the mediation (or remediation) of impaired health and performance. many sleep disorders stem from abnormal respiratory anatomy or sleep-induced changes in respiratory control, underscoring the need for research into the effects of the sleep-wake state on respiratory control processes. whole body plethysmography is being increasingly used to study respiration in freely b ... | 2002 | 12111280 |
| circadian-dependent and circadian-independent behavioral actions of hypocretin/orexin. | the hypocretins/orexins modulate behavioral state as well as a variety of state-dependent behaviors. levels of hypocretin-1 and prepro-hypocretin mrna vary in a circadian fashion, suggesting that hypocretin neurotransmission may vary across the circadian cycle. to better assess the circadian dependency of the behavioral actions of hypocretin-1, the behavioral effects of intracerebroventricular hypocretin-1 administration (3.0 nmol/2 microl) were examined at differing portions of the circadian cy ... | 2002 | 12101045 |
| in vivo microdialysis measures of extracellular norepinephrine in the rat amygdala during sleep-wakefulness. | norepinephrine (ne)-containing locus ceruleus (lc) has been known to participate in the regulation of the sleep-wake cycle according to the differential firing rate. the aim of this study was to know the change of extracellular ne level in the rat amygdala, which are reciprocally connected with lc, during sleep-wakefulness. extracellular ne levels in the rat amygdala were investigated during different stages of the sleep-waking cycle using in vivo microdialysis and polygraphic recording. dialysa ... | 2002 | 12068146 |
| assessment of spontaneously occurring periodic limb movements in sleep in the rat. | periodic limb movements in sleep (plms) are often associated with the restless legs syndrome (rls). although the dopaminergic system seems to be involved, the pathophysiology of plms and rls is still obscure. the objective of this study is to explore whether a plms-like phenomenon can be observed in rodents in order to elucidate the underlying mechanisms. | 2002 | 12039666 |
| the central nucleus of the amygdala and the wake-promoting effects of modafinil. | modafinil, a novel non-amphetamine stimulant recently approved for the treatment of narcolepsy, has been shown to increase waking in both animals and humans. however, its mechanism of action is currently unknown. earlier research into the brain structures responsible for the wake-producing actions of modafinil implicated the central nucleus of the amygdala (ace) as a possible site of action [neuroscience 87 (1998) 905-911; neurosci. lett. 241 (1998) 95-98]. the present experiments were designed ... | 2002 | 12031546 |
| the effect of restraint stress on paradoxical sleep is influenced by the circadian cycle. | it is well known that the physiological impact imposed by events or behaviors displayed during the waking period determines the way organisms sleep. among the situations known to affect sleep both in its duration and quality, stress has been widely studied and it is now admitted that its effects on sleep architecture depend on several factors specific to the stressor or the individual itself. although numerous reports have highlighted the prominent role of the circadian cycle in the physiologica ... | 2002 | 12020861 |
| pre- and post-natal protein malnutrition alters the effect of rapid eye movements sleep-deprivation by the platform-technique upon the electrocorticogram of the circadian sleep-wake cycle and its frequency bands in the rat. | selective deprivation of paradoxical (or rapid eye movements) sleep (rems) in protein malnourished young male rats, results in circadian and homeostatic alterations. by means of electrocorticographic recordings, we have examined the sleep-wake cycle as a functional maturity index, and its circadian and homeostatic mechanisms in prenatal (pm) and chronically (cm) protein malnourished young male rats. the effects of rapid eye movements sleep-deprivation (rems-d), by the platform technique in a "co ... | 2002 | 12000087 |
| melatonin modulates [3h]serotonin release in the rat hippocampus: effects of circadian rhythm. | serotonin (5-ht) participates as a neurotransmitter in the control of the circadian sleep/wake rhythm, feeding and sexual behaviours, and emotional and affective states. the present study investigated whether melatonin affects the circadian rhythm of 5-ht neurotransmission in the hippocampus, a major target for serotoninergic antidepressants. the present results show a daytime dependency of [3h]5-ht uptake insensitive to melatonin, with a peak from 14.00 h to 22.00 h and a trough from 02.00 h to ... | 2002 | 11999718 |
| co2 dialysis in nucleus tractus solitarius region of rat increases ventilation in sleep and wakefulness. | to evaluate the function of widely distributed central chemoreceptors during sleep and wakefulness in the rat, we focally stimulate single chemoreceptor sites during naturally occurring sleep-wake cycles by microdialysis of artificial cerebrospinal fluid equilibrated with 25% co2. in retrotrapezoid nucleus, this increased ventilation (tidal volume) by 24% only in wakefulness (li a, randall m, and nattie e. j appl physiol 87: 910-919, 1999). in caudal medullary raphé, it increased ventilation (fr ... | 2002 | 11960965 |
| distinct sleep-wake stages in rats depend differentially on age. | the objective was to study age-related changes in sleep-wake stages in the rat by using precise polyphysiograph criteria for stage identification. cortical and hippocampal electroencephalogram, and ocular and myographic activities were recorded in young, middle-aged, and old male wistar rats to define 6 stages: active and quiet wake (aw, qw); light and deep slow wave sleep (sws: s1, s2); intermediate stage of sleep (is); and paradoxical sleep (ps). the old rats displayed a decrease in s1, s2, an ... | 2002 | 11958861 |
| [variations of hypothalamic and cortical prostaglandins and monoamines reveal transitions in arousal states: microdialysis study in the rat]. | brain microdialysis coupled with eeg recording allowed us to track dynamic neurochemical changes every 3 or 6 minutes in relation to sleep/wake cycles. we chose to investigate prostaglandins (pg) and monoamines (catecholamines, serotonin and metabolites) because of their respective role in the states of vigilance, mainly suggested by pharmacological approaches, and because of the known interactions between pgs and monoamines. we focused on the paraventricular and ventromedial nuclei of the hypot ... | 2001 | 11924034 |
| [influence of cerebral and peripheral nitric oxide on sleep/wake cycle in the rat]. | through a polygraphic and pharmacological approach conducted in the rat, it is established that l-name (n-nitro-l-arginine methyl ester; an inhibitor of the endothelial and neuronal no-synthases), administered intraperitoneally (i.p., 100 mg/kg) increases significantly slow wave sleep (sws) and paradoxical sleep (ps). on the contrary, 7-ni (7-nitro-indazole; an inhibitor of the neuronal no-synthase), when administered locally in the nrd (n. raphe dorsalis), decreases ps without sws changes. fina ... | 2001 | 11924033 |
| ultradian rhythmicity of ghrelin secretion in relation with gh, feeding behavior, and sleep-wake patterns in rats. | ghrelin, an endogenous ligand for the ghs receptor, stimulates gh secretion and gastrointestinal motility and has orexigenic effects. in this study, the relationships between ghrelin, gh secretion, feeding behavior, and sleep-wake patterns were investigated in adult male rats. the half-life of exogenous ghrelin (10 microg i.v.) in plasma was about 30 min. repeated administration of ghrelin at 3- to 4-h intervals (one during lights-on and two during lights-off periods) increased gh release and fe ... | 2002 | 11897692 |
| the sk-n-mc cell line expresses an orexin binding site different from recombinant orexin 1-type receptor. | orexin a and b (also known as hypocretins), two recently discovered neuropeptides, play an important role in food intake, sleep/wake cycle and neuroendocrine functions. orexins are endogenous ligands of two g-protein-coupled receptors, termed ox1 and ox2. this work presents the first short orexin a and b analogues, orexin a 23-33 and orexin b 18-28, with high affinity (119 +/- 49 and 49 +/- 23 nm) for ox1 receptors expressed on sk-n-mc cells and indicates the importance of the c-terminal part of ... | 2002 | 11856342 |
| expression of lipopolysaccharide binding protein and its receptor cd14 in experimental alcoholic liver disease. | to evaluate the relationship between the expression of lipopolysaccharides (lps) binding protein (lbp) and cd14 mrna and the severity of liver injury in alcohol-fed rats. | 2001 | 11854912 |
| orexin receptor-1 (ox-r1) immunoreactivity in chemically identified neurons of the hypothalamus: focus on orexin targets involved in control of food and water intake. | the neuropeptides orexin-a and orexin-b are produced in neurons of the lateral hypothalamic area and have been implicated to be involved in the regulation of food/water intake and sleep-wake control. the orexins act at two different g-protein-coupled orexin receptors (ox-r1 and ox-r2) that are derived from separate genes and expressed differentially throughout the central nervous system. in the present study, we have used a polyclonal antipeptide antiserum to analyse in detail the distribution o ... | 2002 | 11849298 |
| mesolimbic dopaminergic system is involved in diurnal blood pressure regulation. | parkinson's disease (pd) patients with autonomic failure show no nocturnal decrease in blood pressure (bp). at present, it is not clear if this symptom is attributable to the disturbance of the dopaminergic (da) system that is responsible for pd. in the present study, we determined that the mesolimbic da system is involved in diurnal profiles of the mean bp (mbp) by destroying the a10 da system in rats with 6-hydroxydopamine. in control rats, a clear dip in the mbp and heart rate (hr) occurs dur ... | 2002 | 11844487 |
| orexins and adipoinsular axis function in the rat. | orexin a and b are recently identified as peptides that are derived from the same precursor and their expression is highly specifically localized in neurons located in the lateral hypothalamic area, a region implicated in the feeding behaviour. these peptides appear to be a part of a complex circuit that integrates the aspects of energy metabolism, cardiovascular function, hormone homeostasis and sleep/wake behaviours. the functional linking of orexins with leptin and insulin suggests the possib ... | 2002 | 11830279 |
| effects of sleep-wake state on the genioglossus vs.diaphragm muscle response to co(2) in rats. | the effects of sleep on the ventilatory responses to hypercapnia have been well described in animals and in humans. in contrast, there is little information for genioglossus (gg) responses to a range of co(2) stimuli across all sleep-wake states. given the notion that sleep, especially rapid eye movement (rem) sleep, may cause greater suppression of muscles with both respiratory and nonrespiratory functions, this study tests the hypothesis that gg activity will be differentially affected by slee ... | 2002 | 11796705 |
| sleep-waking discharge patterns of neurons recorded in the rat perifornical lateral hypothalamic area. | the perifornical lateral hypothalamic area (pf-lha) has been implicated in the control of several waking behaviours, including feeding, motor activity and arousal. several cell types are located in the pf-lha, including projection neurons that contain the hypocretin peptides (also known as orexins). recent findings suggest that hypocretin neurons are involved in sleep-wake regulation. loss of hypocretin neurons in the human disorder narcolepsy is associated with excessive somnolence, cataplexy a ... | 2002 | 11790824 |
| gaba(b) receptors in the median raphe nucleus: distribution and role in the serotonergic control of hippocampal activity. | previous studies have shown that serotonergic neurons of the median raphe nucleus have a suppressive effect on theta synchronization in the hippocampus. median raphe lesion, suppression of 5-ht neuronal activity by administration of gaba(a) receptor antagonist or by glutamate blockade or depletion produced long-lasting non-interrupted hippocampal theta in freely behaving rats independent of behavior and in rats anesthetized with urethane. serotonergic neurons show a characteristic sleep-wake pat ... | 2002 | 11784704 |
| sleep of transgenic mice producing excess rat growth hormone. | the effects of chronic excess of growth hormone (gh) on sleep-wake activity was determined in giant transgenic mice in which the metallothionein-1 promoter stimulates the expression of rat gh (mt-rgh mice) and in their normal littermates. in the mt-rgh mice, the time spent in spontaneous non-rapid eye movement sleep (nrems) was enhanced moderately, and rapid eye movement sleep (rems) time increased greatly during the light period. after a 12-h sleep deprivation, the mt-rgh mice continued to slee ... | 2002 | 11742825 |
| chemosensitivity of serotonergic neurons in the rostral ventral medulla. | the medullary raphé contains two subtypes of chemosensitive neuron: one that is stimulated by acidosis and another that is inhibited. both types of neuron are putative chemoreceptors, proposed to act in opposite ways to modulate respiratory output and other ph sensitive brain functions. in this review, we will discuss the cellular properties of these chemosensitive raphé neurons when studied in vitro using brain slices and primary dissociated cell culture. quantification of chemosensitivity of r ... | 2001 | 11738653 |
| variations in extracellular monoamines in the prefrontal cortex and medial hypothalamus after modafinil administration: a microdialysis study in rats. | the role of brain amines in mediating the effects of the wake-promoting agent modafinil, used in the treatment of sleepiness associated with narcolepsy is still uncertain. therefore we studied the effects of modafinil on extracellular serotonin (5-ht), dopamine (da) and noradrenaline (na), in rat prefrontal cortex and in the medial hypothalamus area. modafinil (128 mg/kg i.p.) significantly increased waking in the first 4 h of eeg sleep recording. this cortical and behavioral activation was asso ... | 2001 | 11733706 |
| orexin a and b evoke noradrenaline release from rat cerebrocortical slices. | 1. orexin a and b, recently identified in the rat hypothalamus are endogenous neuropeptide agonists for the g-protein coupled orexin-1 (ox1) and orexin-2 (ox2) receptors. 2. in the present study, we have examined the effects of orexin a, b and raised extracellular k(+) on noradrenaline release from the rat cerebrocortical slice. we have compared this with other sleep-wake-related (excitatory) neurotransmitters; dopamine, glutamate, serotonin and histamine. 3. neurotransmitter release studies wer ... | 2001 | 11724752 |
| an adenosine a2a agonist increases sleep and induces fos in ventrolateral preoptic neurons. | considerable evidence indicates that adenosine may be an endogenous somnogen, yet the mechanism through which it promotes sleep is unknown. adenosine may act via a1 receptors to promote sleep, but an a2a receptor antagonist can block the sleep induced by prostaglandin d(2). we previously reported that prostaglandin d(2) activates sleep-promoting neurons of the ventrolateral preoptic area, and we hypothesized that an a2a receptor agonist also should activate these neurons. rats were instrumented ... | 2001 | 11720788 |
| electrophysiological analysis of suprachiasmatic nucleus projections to the ventrolateral preoptic area in the rat. | the circadian pacemaker housed in the suprachiasmatic nucleus (scn) synchronizes daily sleep-wake cycles, presumably by modulating the sleep-wake regulatory system, including ventrolateral preoptic area (vlpo) neurons. we used whole-cell patch-clamp recording to study the projections from the scn to the vlpo in horizontal slices of rat hypothalamus. single-pulse stimulation of the scn region elicited postsynaptic currents (pscs) in 20 of 66 neurons (30%) recorded within the vlpo region as verifi ... | 2001 | 11703455 |
| further definition of the effect of corticosterone on the sleep-wake pattern in the male rat. | it is well known that the activation of the hypothalamic-pituitary-adrenal (hpa) axis can induce alterations in the sleep-wake pattern. corticotropin-releasing factor (crf), adrenocorticotropin, and corticosterone are involved in the activation of the axis and each one of them has shown an effect on wakefulness and sleep. nevertheless, concerning corticosterone, the picture is still controversial. in the present study, we analyzed the effects of a low (lc, 0.2 mg), medium (mc, 2 mg), and high (h ... | 2001 | 11701201 |