Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| high corticosterone levels in prenatally stressed rats predict persistent paradoxical sleep alterations. | prenatal stress predisposes rats to long-lasting disturbances that persist throughout adulthood (e.g., high anxiety, dysfunction of the hypothalamo-pituitary-adrenal axis, and abnormal circadian timing). these disturbances parallel to a large extent those found in depressed patients, in which hypercortisolemia and sleep alterations may be related to stress-inducing events. we studied sleep-wake parameters in control and prenatally stressed adult rats (3-4 months old) and examined possible relati ... | 1999 | 10493766 |
| orexin a activates locus coeruleus cell firing and increases arousal in the rat. | the localization of orexin neuropeptides in the lateral hypothalamus has focused interest on their role in ingestion. the orexigenic neurones in the lateral hypothalamus, however, project widely in the brain, and thus the physiological role of orexins is likely to be complex. here we describe an investigation of the action of orexin a in modulating the arousal state of rats by using a combination of tissue localization and electrophysiological and behavioral techniques. we show that the brain re ... | 1999 | 10485925 |
| psychogenetically selected (roman high- and low-avoidance) rats differ in 24-hour sleep organization. | a comparison of sleep organization in roman high-(rha/verh) and low-(rla/verh) avoidance rats, which differ in the way they respond to environmental stimuli and in several neuroendocrine and neurochemical parameters, was carried out. eeg-sleep recordings were obtained from adult males over 12:12 light-dark periods to determine how these two psychogenetically selected rat lines might also differ in their sleep-wake cycle. there was no significant difference in total sleep time between the two lin ... | 1999 | 10452334 |
| forced desynchrony of circadian rhythms of body temperature and activity in rats. | the daily rhythm in body temperature is thought to be the result of the direct effects of activity and the effects of an endogenous circadian clock. forced desynchrony (fd) is a tool used in human circadian rhythm research to disentangle endogenous and activity-related effects on daily rhythms. in the present study, we applied an fd protocol to rats. we subjected 8 rats for 5 days to a 20 h forced activity cycle consisting of 10 h of forced wakefulness and 10 h for rest and sleep. the procedure ... | 1999 | 10442237 |
| immunohistochemical distribution of the somatostatin receptor subtype 5 in the adult rat brain: predominant expression in the basal forebrain. | somatostatin exerts its actions by means of a family of g protein-coupled receptors, five of which have so far been cloned. whereas mrnas for receptor subtypes sst(1)-sst(4) have been unequivocally localized in the brain, the data concerning the fifth subtype, sst(5), are contradictory. moreover, whereas sst(1) and sst(2a) receptor proteins have been localized by immunohistochemistry, the distribution of sst(3)-sst(5) receptor proteins and/or subtype-specific binding remains to be determined in ... | 1999 | 10440710 |
| retinal input to the sleep-active ventrolateral preoptic nucleus in the rat. | light-dark periodicity and luminance play important roles in regulating sleep-wake cycles. we recently identified a discrete cluster of sleep-active cells in the ventrolateral preoptic nucleus that we hypothesize plays a central role in sleep regulation. these ventrolateral preoptic nucleus neurons are gabaergic and galaninergic and innervate the monoaminergic cell groups that contribute to the ascending arousal system. to determine whether there are retinal inputs to sleep-active ventrolateral ... | 1999 | 10430484 |
| hypoprolactinemic rats under conditions of constant darkness or constant light. effects on the sleep-wake cycle, cerebral temperature and sulfatoxymelatonin levels. | in genetic hypoprolactinemic rats under light-dark (ld) conditions, the circadian rhythms of slow-wave (sws) and paradoxical (ps) sleep display an alteration of their phase relationship. the aim of our study was to investigate the effects of constant darkness (dd) or constant light (ll) on the daily distribution and amounts of sleep-wake stages, cerebral temperature and concentrations of the urinary melatonin metabolite, 6-sulfatoxymelatonin, in prolactin-deficient rats. after 3 weeks of dd, the ... | 1999 | 10415384 |
| critical threshold cerebral hypoperfusion causes alzheimer's disease? | after nearly a century of inquiry, the cause of alzheimer's disease (ad) remains to be found. in this review, basic and clinical evidence is presented that assembles and hypothetically explains most of the key pathologic events associated with the development of ad. these pathologic events are triggered in ad by an impaired cerebral perfusion originating in the microvasculature which affects the optimal delivery of glucose and oxygen and results in a breakdown of metabolic energy pathways in bra ... | 1999 | 10412794 |
| blockade of 5-hydroxytryptamine (serotonin)-2 receptors alters interleukin-1-induced changes in rat sleep. | recent data suggest that interleukin-1-induced enhancement of non-rapid eye movement sleep is mediated, in part, by the serotonergic system. to determine if sleep changes induced by interleukin-1 are mediated by a specific serotonergic receptor subtype, we evaluated interleukin-1 effects on sleep in rats pretreated with the 5-hydroxytryptamine (serotonin)-2 receptor antagonist ritanserin. ritanserin (0.63 mg/kg, intraperitoneally) by itself did not alter sleep-wake behavior, although it did redu ... | 1999 | 10408622 |
| nitric oxide and sleep in the rat: a puzzling relationship. | to date, only a few studies indicate that nitric oxide may play a role in the regulation of the sleep-wake cycle. however, data reported are controversial and the part played by nitric oxide in sleep-wake cycle regulation still remains uncertain. in the present report, we studied the effects on sleep amounts of two different nitric oxide synthase inhibitors: n-nitro-l-arginine methyl ester, a non-selective nitric oxide synthase inhibitor, and 7-nitro-indazole, a specific inhibitor of neuronal ni ... | 1999 | 10408611 |
| a comparative study of quiet sleep, active sleep, and waking on the first 2 days of life. | direct behavioral observation and motility monitoring procedures provide reliable data, and both are appropriate for sleep/wake state measurements starting immediately after birth. using these procedures, newborn rats, rabbits, and humans were found to have a greater amount of quiet sleep on the day of birth rather than 24 hr later. changes in active sleep and wake were inconsistent across the 2 days. the quiet sleep findings are contrary to the developmental course which increases with age. the ... | 1999 | 10397895 |
| automated sleep staging systems in rats. | one of the major inconveniences encountered in sleep studies is the time consuming labor involved in equating visual analysis of physiological recordings (eeg, emg, eog, ...) to an appropriate state of vigilance. the explosion of computer technology is responsible for the emergence of several automated sleep-wake staging systems to supplement human analysis. conversely to human sleep analysis, rat sleep is characterized by the absence of consensus about numerous elements constituting the sleep-w ... | 1999 | 10389657 |
| hypothalamic serotonergic activity correlates better with brain temperature than with sleep-wake cycle and muscle tone in rats. | the activity of the serotonergic system varies in phase with the sleep-wake cycle, which is associated with changes in several physiological functions, including electroencephalographic activity, brain temperature, and locomotion. the aim of the present study was to clarify which of these parameters correlates better with serotonergic activity in spontaneous conditions. voltammetric recordings by telemetry of serotonergic metabolism in the medial preoptic area and polygraphic recordings of sleep ... | 1999 | 10362311 |
| hippocampal type 1 (movement-related) theta rhythm positively correlates with serotonergic activity. | to investigate the relationship between the hippocampal [symbol: see text] activity (or rhythmical slow activity, rsa) and the hippocampal serotonergic activity during spontaneous behavior, simultaneous recordings of i) hippocampal eeg, ii) sleep-wake activity, and iii) hippocampal levels of the serotonin (5-ht) metabolite 5-hydroxyndolacetic acid (5-hiaa--measured by in vivo voltammetry and infrared telemetry) were performed. the results show that hippocampal type 1 rsa recorded during wakefuln ... | 1999 | 10349493 |
| acute and chronic blood pressure response to recurrent acoustic arousal in rats. | repetitive episodic hypoxia every 30 sec administered chronically to sprague-dawley (sd) rats has been shown by previous studies to cause a sustained increase in daytime blood pressure (bp). acoustic arousal in humans during wake or sleep produces an acute bp rise. the question then arises as to whether chronic episodic acoustic arousal applied with the same frequency and duration as episodic hypoxia induces elevated bp. we exposed 14-week-old (n = 10) sd rats in individual cages to recurrent bu ... | 1999 | 10342789 |
| region-dependent difference in the sleep-promoting potency of an adenosine a2a receptor agonist. | the present study has demonstrated that the sleep-promoting potency of 2-[p-(2-carboxyethyl)phenethylamino]-5'-n-ethylcarboxamido adenosine (cgs21680), a selective agonist for the adenosine a2a receptor, varies depending on the location of the administration. cgs21680 was continuously administered to rats through a chronically implanted cannula for 6 h during their active phase. the tip of the cannula was located in the subarachnoid space or the brain ventricle neighbouring the established brain ... | 1999 | 10215911 |
| subnuclear organization of the rat habenular complexes. | the habenular complexes represent phylogenetically constant structures in the diencephalon of all vertebrates. available evidence suggests that this area is engaged in a variety of important biological functions, such as reproductive behaviors, central pain processing, nutrition, sleep-wake cycles, stress responses, and learning. based on nissl-stained sections, one medial nucleus and two lateral nuclei (divisions) have been widely accepted in the rat. cytochemical, hodologic, and functional stu ... | 1999 | 10213193 |
| age-related changes in sleep in the rat. | human sleep in old age is characterized by a number of changes, including reductions in sleep efficiency, amounts of visually scored slow-wave and rem sleep, and amplitude of the diurnal sleep/wake rhythm. in older rats, some, but not all, of these traits have been reported, including a decrease in the mean duration of sleep bouts, an increase in the number of sleep bouts, and a modest reduction of rem sleep. studies of the diurnal rhythm of total sleep have had varied results. there are, howeve ... | 1999 | 10201059 |
| neurotolerability of gadobenate dimeglumine in a rat model of focal brain ischemia: eeg evaluation. | the neurologic pathologies for which contrast-enhanced mri is indicated are often accompanied by a disruption of the blood-brain barrier (bbb), which allows the contrast agent to come into contact with the nervous tissue. thus, assessment of the neurologic safety for a new contrast agent is of crucial importance. the objective of this study was to assess the neurotolerability of the new mri contrast agent gadobenate dimeglumine using eeg in the presence of focal lesions of the bbb. | 1999 | 10196717 |
| sino-aortic denervation augments the increase in blood pressure seen during paradoxical sleep in the rat. | using a computer assisted telemetric system, we have re-examined the effect of sino-aortic denervation (sad) on the changes in arterial blood pressure (ap) and heart rate (hr) during sleep in the rat suitably recovered from the operation. eight 1 hourly polygraphic recordings were performed 4 weeks after the initial sad surgery. in the sad rats, the increase in ap during paradoxical sleep (ps) was much larger than that in sham-operated rats. hr in the sad rats increased on-going from slow-wave s ... | 1999 | 10188135 |
| fos expression in the sleep-active cell group of the ventrolateral preoptic area in the diurnal murid rodent, arvicanthis niloticus. | the ventrolateral preoptic area (vlpo) of the nocturnal laboratory rat receives direct input from the retina and is active during sleep; however, nothing is known about vlpo function in day-active (diurnal) species. in the first study, we used 24-h videotaping of arvicanthis niloticus, a diurnal murid rodent, to estimate the distribution of sleep and wakefulness across a 12:12 light-dark cycle. based on behavioral data, a. niloticus were perfused at a time when the animals are inactive (zeitgebe ... | 1999 | 10082823 |
| insulin-like growth factor-1 (igf-1)-induced inhibition of growth hormone secretion is associated with sleep suppression. | the hypothalamic growth hormone (gh)-releasing hormone (ghrh) promotes non-rapid eye movement sleep (nrems). insulin-like growth factor-1 (igf-1) acts as a negative feedback in the somatotropic axis inhibiting ghrh and stimulating somatostatin. to determine whether this feedback alters sleep, rats and rabbits were injected intracerebroventricularly (i.c.v.) with igf-1 (5.0 and 0.25 microgram, respectively) and the sleep-wake activity was studied. compared to baseline (i.c.v. injection of physiol ... | 1999 | 10082812 |
| intrapreoptic microinjection of ghrh or its antagonist alters sleep in rats. | previous reports indicate that growth hormone-releasing hormone (ghrh) is involved in sleep regulation. the site of action mediating the nonrapid eye movement sleep (nrems)-promoting effects of ghrh is not known, but it is independent from the pituitary. ghrh (0.001, 0. 01, and 0.1 nmol/kg) or a competitive antagonist of ghrh (0.003, 0.3, and 14 nmol/kg) was microinjected into the preoptic area, and the sleep-wake activity was recorded for 23 hr after injection in rats. ghrh elicited dose-depend ... | 1999 | 10066272 |
| prostaglandin d2 and sleep regulation. | prostaglandin (pg) d2 is recognized as the most potent endogenous sleep-promoting substance whose action mechanism is the best characterized among the various sleep-substances thus far reported. the pgd2 concentration in rat cerebrospinal fluid (csf) shows a circadian change coupled to the sleep-wake cycle and elevates with an increase in sleep propensity during sleep deprivation. lipocalin-type pgd synthase is dominantly produced in the arachnoid membrane and choroid plexus of the brain, and is ... | 1999 | 9989291 |
| ionic mechanisms of action of neurotensin in acutely dissociated neurons from the diagonal band of broca of the rat. | whole cell recordings were performed on acutely dissociated neurons from the horizontal limb of the diagonal band of broca (hdbb) from rats to elucidate the ionic mechanisms of action of neurotensin. neurotensin caused a decrease in whole cell voltage-activated outward currents and failed to elicit a response when ca2+ influx was blocked by changing the external solution to the one containing 0 mm ca2+ and 50 microm cd2+, suggesting the involvement of ca2+-dependent conductances. charybdotoxin, ... | 1999 | 9914284 |
| manipulations during forced wakefulness have differential impact on sleep architecture, eeg power spectrum, and fos induction. | we propose a hypothesis suggesting that the most prominent experiences occurring during wakefulness activate specific clusters of neurons related to such experiences. these neurons could possibly then evoke the release of various types of sleep-inducing molecules, thereby causing different patterns of sleep architecture. in this study, we therefore sought to determine whether manipulations of behavior during wakefulness, such as forced wakefulness induced by gentle handling, forced wakefulness a ... | 1998 | 9886782 |
| endogenous nitric oxide in the rat pons promotes sleep. | pontine cholinergic structures are known to play a key role in the regulation of vigilance states associated with desynchronised eeg, i. e., wakefulness and paradoxical sleep. as the cholinergic cells of these nuclei, the pedunculopontine tegmentum (ppt) and the laterodorsal tegmentum, are enriched with nitric oxide synthase (nos), we tested the hypothesis that nitric oxide (no) in the pons is implicated in wake and sleep regulation. for this reason, a nos inhibitor, a no precursor and a no dono ... | 1999 | 9878741 |
| localization of nitric oxide-synthesizing neurons sending projections to the dorsal raphe nucleus of the rat. | the origin of the nerve fibers immunoreactive for neuronal nitric oxide synthase (nnos) in the rat dorsal raphe nucleus (drn) was determined by combining the use of cholera toxin subunit b (ctb) as a retrograde tracer and nnos immunohistochemistry with a monoclonal anti-nnos antibody. double labeled ctb-nnos cell bodies were distributed from the rostral diencephalon to the caudal medulla oblongata, in about 20 areas of the brain. several of the areas displaying double labeled cells are known for ... | 1998 | 9870341 |
| the fasciculus retroflexus controls the integrity of rem sleep by supporting the generation of hippocampal theta rhythm and rapid eye movements in rats. | the fasciculus retroflexus (fr) fiber bundle comprises the intense cholinergic projection from the medial division of the habenula nucleus (hbn) of the epithalamus to the interpeduncular nucleus (ipn) of the limbic midbrain. due to the widespread connections of the hbn and ipn, it could be surmised that the fr is integrated in the processings of various subsystems that are known to be involved in the sleep-wake mechanisms; relevant sites include the limbic forebrain and midbrain areas and more c ... | 1998 | 9820735 |
| daily rhythms in fos activity in the rat ventrolateral preoptic area and midline thalamic nuclei. | the present experiment investigated the expression of the nuclear phosphoprotein fos over the 24-h light-dark cycle in regions of the rat brain related to sleep and vigilance, including the ventrolateral preoptic area (vlpo), the paraventricular thalamic nucleus (pvt), and the central medial thalamic nucleus (cmt). immunocytochemistry for fos, an immediate-early gene product used as an index of neuronal activity, was carried out on brain sections from rats perfused at zeitgeber time (zt) 1, zt 5 ... | 1998 | 9791082 |
| output signals of the scn. | the suprachiasmatic nucleus (scn) of the hypothalamus controls circadian rhythmicity in mammals (for reviews, see refs. 33 and 59). responses modulated by the scn are numerous and include rhythms in sleep/wake cycles, locomotor, gnawing and general activity, temperature, ingestive behavior, and rhythms of hormonal and peptide secretions. though a great deal is known about the neuroanatomical organization of the scn, many elements of the structure-function relationships remain to be discovered. f ... | 1998 | 9787940 |
| morphological substrates underlying opioid, epinephrine and gamma-aminobutyric acid inhibitory actions in the rat locus coeruleus. | the locus coeruleus (lc) has been implicated in attentional processes related to orienting behaviors, learning and memory, anxiety, stress, the sleep-wake cycle, and autonomic control, as well as to contributing to the affective state. direct activation of lc neurons causes desynchronization of the electroencephalogram, suggesting that the lc is an important modulator of the behavioral state. the lc has been an intensely studied neuronal system, as the physiology and pharmacology of this nucleus ... | 1998 | 9766384 |
| brain regional substrates for the actions of the novel wake-promoting agent modafinil in the rat: comparison with amphetamine. | modafinil is a novel wake-promoting compound for which the mechanism and sites of action are unknown. we examined the neural substrates in the brain for the actions of modafinil using 2-deoxyglucose autoradiography and compared the findings to those obtained with amphetamine. modafinil showed a relatively restricted pattern of changes in brain regional metabolic activity, while amphetamine altered glucose utilization in a wide variety of brain regions. both modafinil and amphetamine increased gl ... | 1998 | 9759978 |
| subdiaphragmatic vagotomy does not block sleep deprivation-induced sleep in rats. | cytokines, such as interleukin-1beta (il-1beta), are involved in physiological sleep regulation and in the sleep responses to sleep deprivation. sleep deprivation increases systemic cytokine levels and recent evidence suggests that cytokine-to-brain communication occurs via the vagus nerve. furthermore, the vagus nerve plays a role in sleep responses elicited by feeding and vagal activity affects electroencephalographic (eeg) activity. thus, this study examined sleep-wake activity and brain temp ... | 1998 | 9748105 |
| albumin enhances sleep in the young rat. | rats 4 to 7 days after weaning received intraperitoneal (i.p.) injections of vehicle (baseline day), and either serum (2 ml of lyophilized rabbit serum), 140 mg of rat albumin, or hyperosmotic nacl (experimental day). injections were given 1 h before light onset. sleep-wake activity and cortical brain temperature were recorded during the subsequent 12-h light period. the intensity of non-rapid eye movement sleep (nrems) was characterized by the power density values of the electroencephalogram sl ... | 1998 | 9748091 |
| [are active neurons a better defense against aging in alzheimer's disease?]. | this article deals with the question whether metabolic activity of neurons interferes with their survival during brain aging and alzheimer's disease (ad). this 'use it or lose it' concept assumes that active neurons have a better chance to survive these conditions. we have monitored activity changes in human hypothalamic nuclei, that show differential survival patterns in aging and ad. the size of the golgi apparatus (ga) was measured in e.g. the nucleus basalis of meynert (nbm), that is severel ... | 1998 | 9746932 |
| adrenergic and cholinergic inputs in preoptic area of rats interact for sleep-wake thermoregulation. | isolated studies have shown that both norepinephrine and acetylcholine into the medial preoptico-anterior hypothalamic area tonically regulate sleep-wake and body temperature. a possible interaction between these neurotransmitters for the regulation of such functions has been investigated in this study. to study this interaction a combination of either prazosin and carbachol or, scopolamine and methoxamine was injected into the medial preoptico-anterior hypothalamic area and the effect on sleep, ... | 1998 | 9738535 |
| rolipram, an antidepressant that increases the availability of camp, transiently enhances wakefulness in rats. | a study was carried out on the effects on sleep of rolipram, an antidepressant that increases the availability of camp by inhibiting a phosphodiesterase isoenzyme. rats were treated with rolipram (0.1 or 1 mg/kg) twice a day (at light and dark onset) for 11 days, after a chronic period of injection of physiological saline for habituation purposes. the sleep-wake activity was recorded for 12 h following the injection at light onset on the baseline day (physiological saline), on rolipram days 1, 5 ... | 1998 | 9700966 |
| measurements of behavior in the naked mole-rat after intraperitoneal implantation of a radio-telemetry system. | the naked mole-rat (heterocephalus glaber) is a unique fossorial mammal that is eusocial, object blind, and virtually poikilothermic. this animal is an ideal model to examine questions pertaining to the thermoregulatory aspects of sleep/wake cycles and other circadian events. however, the monitoring of mammalian sleep usually involves implanting permanent electrodes into the skull which are linked to a counter-weighted cable apparatus. this is not a viable option for h. glaber because of the tun ... | 1998 | 9696320 |
| [melatonin: a popular hormone]. | this contribution makes an attempt to critically reassess the impressive career of melatonin (mel) from a stepchild of hormone research to a best-seller of drug marketing. melatonin, the hormone of the pineal gland, provides temporal information on diurnal and seasonal variation to the body and brain and it is involved in the synchronization of many different aspects of circadian systems to the light-dark cycle. in addition to these receptor-mediated functions, mel may act as a modulator of intr ... | 1998 | 9676179 |
| 5-hydroxyindoles compounds and nitric oxide voltammetric detection in the rat brain: changes occurring throughout the sleep-wake cycle. | the release of serotonin may occur throughout the sleep-wake cycle according to 2 different modalities: - by the axonal nerve endings during waking; - by the dendrites and/or the soma of the nucleus raphe dorsalis (nrd) during sleep. neuronal nitric oxide (no), synthesised by constitutive no synthase (nos), is colocalized with neurotransmitters such as gaba, acetylcholine, somatostatin, serotonin, etc. in order to evaluate its modalities of release throughout the rat sleep-wake cycle, a sensor a ... | 1998 | 9660098 |
| noradrenaline neurotoxin dsp-4 effects on sleep and brain temperature in the rat. | n-(2-chloroethyl)-n-ethyl-2-bromobenzylamine (dsp-4) has a selective degenerative effect on noradrenergic fibers originating from locus coeruleus (lc) neurons. in the present study, we studied its effect on vigilance states and brain temperature by continuous recordings for periods of 1-5 days and 2-4 weeks following dsp-4 treatment. on the first day, paradoxical sleep duration was significantly decreased (-67%, p < 0.05), slow-wave sleep (sws) duration increased (+16%, p < 0.05) up to 48 h afte ... | 1998 | 9654350 |
| age-dependent effect of ketanserin on the sleep-waking phases in rats. | the age-dependent effect of the specific 5-ht2 receptor antagonist ketanserin at two doses (1 mg/kg and 6 mg/kg) on six sleep-waking phases was electroencephalographically (eeg) examined in young, middle-aged, and old male wistar rats. because 5-ht2 receptor binding sites decrease with aging, the question of whether ketanserin can produce any effect on sleep-wake in advanced age was addressed. ketanserin enhanced deep slow wave sleep in the three age groups. however, in the old rats this effect ... | 1998 | 9639243 |
| influence of cedar essence on spontaneous activity and sleep of rats and human daytime nap. | we investigated whether exposure to the odor of extracted cedar essence (ce) has (i) an influence on spontaneous activity and sleep-wake states of rats and (ii) a sleep-promoting effect on human daytime nap after taking an ordinary night's sleep. in rats exposed to ce, spontaneous activities and amount of wake were significantly decreased, while the amount of non-rapid eye movement (nrem) sleep was significantly increased. in human daytime nap, nrem sleep stage 2 latency was significantly shorte ... | 1998 | 9628112 |
| compensatory sleep responses to wakefulness induced by the dopamine autoreceptor antagonist (-)ds121. | the effect of the dopamine autoreceptor antagonist (-)ds121 on wakefulness, locomotor activity, body temperature and subsequent compensatory sleep responses was examined in the rat. animals entrained to a light-dark cycle were treated at 5 h after lights-on (ct-5) with 0.5, 1, 5 or 10 mg/kg i.p. (-)ds121 or methylcellulose vehicle. an additional group received 5 mg/kg i.p. (-)ds121 or vehicle 6 h after lights-off (ct-18). at ct-5, (-)ds121 dose-dependently increased wakefulness, locomotor activi ... | 1998 | 9618410 |
| innervation of histaminergic tuberomammillary neurons by gabaergic and galaninergic neurons in the ventrolateral preoptic nucleus of the rat. | the tuberomammillary nucleus (tmn) is the major source of histaminergic innervation of the mammalian brain and is thought to play a major role in regulating wake-sleep states. we recently found that sleep-active neurons in the ventrolateral preoptic nucleus (vlpo) provide a major input to the tmn, but the specificity of this projection and the neurotransmitters involved remain unknown. in this study, we examined the relationship of vlpo efferents to the tmn using both retrograde and anterograde ... | 1998 | 9614245 |
| cortical and thalamic visual evoked potentials during sleep-wake states and spike-wave discharges in the rat. | flash visual evoked potentials (vep) were simultaneously recorded from the primary visual cortex and the dorsal lateral geniculate nucleus in freely-moving wag/rij rats, to investigate whether the thalamic vep shows the same state-dependent alterations as the cortical vep. veps obtained during active and passive wakefulness (aw and pw), slow-wave sleep (sws), rem sleep and during the occurrence of spike-wave discharges (swd), a specific trait of the genetically epileptic wag/rij rat, were compar ... | 1998 | 9607520 |
| altered neuronal activity rhythm and glutamate receptor expression in the suprachiasmatic nuclei of trypanosoma brucei-infected rats. | the parasites trypanosoma brucei cause african trypanosomiasis (sleeping sickness), a severe neuropsychiatric disease with marked disturbances of sleep-wake alternation. the sites of brain lesions are not well characterized. the present experimental investigation is focused on the hypothalamic suprachiasmatic nuclei, which play a role of a biological clock entraining endogenous rhythms in the mammalian brain. the electrophysiological properties of these neurons were analyzed in slice preparation ... | 1998 | 9600194 |
| effects of muscimol or homotaurine on sleep-wake states in alcohol-dependent rats during withdrawal. | sleep-wake states were studied following withdrawal in 36 adult male wistar alcohol-dependent rats, after chronic administration of ethanol (10 g/kg/24 h) for 13 days. in the light phase of the withdrawal day, 12 alcohol-dependent rats received muscimol (0.25 mg/kg), 12 received homotaurine (140 mg/kg), and 12 received 0.9% physiological saline (10 ml/kg). the results have been compared with a control group of 36 rats that received water during the treatment phase of the experiment, and the 14th ... | 1998 | 9586855 |
| blood glucose and ischemic brain damage. | the effect of hyperglycemia on ischemic brain damage was studied in a rat model of incomplete ischemia. incomplete ischemia was produced by permanent occlusion of one (either left or right) common carotid artery (cca). hyperglycemia was induced by intraperitoneal injection of 50% glucose, and same volume of physiological saline was injected in the controls 40 min before cca ligation. serum glucose level, at the time of vessel ligation, was 33.3 mmol/l. after cca ligation, the rats were allowed t ... | 1998 | 9581071 |
| effects of temperature on sleep in the developing rat. | in altricial species, such as humans and rats, much of the development of autonomic systems occurs postnatally. consequently, vulnerabilities exist early in postnatal development when immature autonomic functions are challenged by external factors such as variations in ambient temperature (ta). ta profoundly influences sleep/wake state structure in adult animals and humans, and exposure to excessive warmth has been implicated as a risk factor in sudden infant death syndrome. to better understand ... | 1998 | 9575973 |
| the effects of sensory stimulation on rem sleep duration. | previous experiments have demonstrated that auditory (as) and/or somatosensory (ss) stimulation can increase the duration of rem sleep periods in rats, cats and humans. the objectives of this study were to determine whether repeated as stimulation causes habituation to the stimulus and whether any additive effects could be obtained with the simultaneous application of as and ss. three experimental procedures were used in this study. in experiment 1, animals were recorded for 4 consecutive days w ... | 1998 | 9542797 |
| origin of the neurotensinergic innervation of the rat basal forebrain studied by retrograde transport of cholera toxin. | basal forebrain cholinergic neurons project to the hippocampus and cerebral cortex where they play an important role in cortical activation, attention, and memory. these neurons have been shown to express functional neurotensin receptors and to receive a dense neurotensinergic innervation. in the present study, we investigated the origin of this innervation by combining retrograde transport of cholera toxin with immunohistochemical detection of neurotensin. after injection of cholera toxin in th ... | 1998 | 9527539 |
| differential modulation of high-frequency gamma-electroencephalogram activity and sleep-wake state by noradrenaline and serotonin microinjections into the region of cholinergic basalis neurons. | several lines of evidence indicate that cholinergic basalis neurons play an important role in cortical activation. the present study was undertaken to determine the effect of noradrenergic and serotonergic modulation of the cholinergic neurons on cortical eeg activity and sleep-wake states. the neurotransmitters were injected into the region of the basalis neurons by remote control in freely moving, naturally sleeping-waking rats during the day when the rats are normally asleep the majority of t ... | 1998 | 9502823 |
| effects of paradoxical sleep deprivation on thermoregulation in the rat. | rats were subjected to chronic paradoxical sleep deprivation (psd) by the disk-over-water method to determine if they would develop the sustained increase in core (hypothalamic) temperature (t(hy)); elevated temperature setpoint (tset); and the attenuation of the normal decline in core temperature during the transition from wake to sleep observed in rats subjected to total sleep deprivation (tsd). psd rats did not show a significant elevation in t(hy). psd rats and their yoked controls (psc) wer ... | 1998 | 9485528 |
| on-line detection of extracellular levels of serotonin in dorsal raphe nucleus and frontal cortex over the sleep/wake cycle in the freely moving rat. | we used in vivo microdialysis coupled with polygraphic recording to monitor 5-hydroxytryptamine levels in the dorsal raphe nucleus and frontal cortex across waking, slow-wave sleep and rapid eye-movement sleep. male sprague-dawley rats were prepared with electroencephalogram and electromyogram electrodes. microdialysis probes were placed in dorsal raphe nucleus and/or frontal cortex. dialysate samples were manually collected during polygraphically-defined behavioural states and the level of sero ... | 1998 | 9483564 |
| eeg power densities (0.5-20 hz) in different sleep-wake stages in rats. | frontofrontal and frontoparietal eeg power densities (0.5-20 hz) in waking, light and deep slow-wave sleep, transition-type sleep, and rapid-eye-movement (rem) sleep were investigated for 8 h during the light period in 16 male wistar rats. the data indicate that as delta activity (0.5-4.5 hz) increased from light to deep slow-wave sleep, the number of epochs per scoring epoch with high sigma activity (11-16 hz) as well as power densities in the rest of the spectrum (5-20 hz) including sigma freq ... | 1998 | 9469736 |
| activation of a distinct arousal state immediately after spontaneous awakening from sleep. | in contrast to the many neural studies into the mechanisms of sleep onset and maintenance, few studies have focused specifically on awakening from sleep. however, the abrupt electrographic changes and large brief cardio-respiratory activation at awakening suggest that a distinct, transiently aroused, awake state may exist compared to later wakefulness. to test this hypothesis we utilized the acoustic startle reflex, a standard un-conditioned reflex elicited by a sudden loud noise. this reflex is ... | 1997 | 9462884 |
| hazard assessment of boric acid in toys. | boric acid (h3bo3) has been used in a wide variety of applications--medication, pesticides, and household products. reports of child poisoning by h3bo3 were common in the clinical literature before 1975. however, a decline in its use as a bacteriostatic agent coupled with increased regulatory control has almost eliminated poisonings by accidental ingestion. schedule i (part i, item 8) of the hazardous products act of canada, proclaimed in the late 1960s, followed in the wake of concerns about ac ... | 1997 | 9441917 |
| design and construction of a long-term continuous video-eeg monitoring unit for simultaneous recording of multiple small animals. | in recent years several new rat models of human limbic/mesial temporal lobe epilepsy have been described [1,2,4-7,11,15-17]. unlike earlier models such as kindling in which the seizures are induced by an exogenous stimulus, these new models are characterized by seizures that occur spontaneously at random intervals. although the spontaneity of the seizures makes these models more like human epilepsy, documentation of these seizures by direct observation is highly inefficient, and sub-behavioral e ... | 1997 | 9438076 |
| rat strain differences suggest a role for corticotropin-releasing hormone in modulating sleep. | corticotropin-releasing hormone (crh) mediates many of the hormonal, behavioral, and autonomic responses to a variety of stressors. there is also evidence suggesting that crh may be involved in the modulation of physiologic waking. lewis (lew) rats possess a hypothalamic gene defect that results in reduced synthesis and secretion of crh relative to genetically related fischer 344 (f344) and sprague-dawley (sp-d) rat strains. we therefore hypothesized that lew rats would spend less time awake, an ... | 1997 | 9402617 |
| effects of sleep on wake-induced c-fos expression. | we investigated the effects of sleep on wake-induced c-fos expression in the cerebral cortex of rats and c-fos-lacz transgenic mice. in the cortex of rats, the levels of c-fos, detected both by immunocytochemistry and western blot, remained high during 6 or 12 hr of enforced wakefulness but declined rapidly (within 1 hr) with increasing time of recovery sleep. similarly, in the transgenic mice in which lacz expression is driven from the c-fos promoter, beta-galactosidase activity was high after ... | 1997 | 9391027 |
| cardiopulmonary control in sleeping sprague-dawley rats treated with hydralazine. | to test the hypothesis that hydralazine can suppress spontaneous sleep-related central apnea, respiratory pattern, blood pressure, and heart period were monitored in sprague-dawley rats. in random order and on separate days, rats were recorded after intraperitoneal injection of 1) saline or 2) 2 mg/kg hydralazine. normalized minute ventilation (nvi) declined significantly with transitions from wake to non-rapid-eye-movement (nrem) sleep (-5.1%; p = 0.01) and rapid-eye-movement (rem) sleep (-4.2% ... | 1997 | 9390968 |
| diurnal changes of blood pressure, heart rate and body temperature during sleep in the rat. | we have studied diurnal changes in mean arterial pressure (map), heart rate (hr) and body temperature (tb) during wake (w), non-rapid eye movement sleep (nrems) and rem sleep (rems) in the rat. although hr and tb show a similar sinusoidal diurnal variation during all vigilance states, the diurnal profile for the map is vigilance-state dependent. during w, map values are higher during the dark phase, during nrems, no significant diurnal change is seen, and during rems, the map exhibits a reversed ... | 1997 | 9377530 |
| muramyl dipeptide and il-1 effects on sleep and brain temperature after inhibition of serotonin synthesis. | the role of the interactions between serotonin (5-ht) and muramyl dipeptide (mdp) and interleukin-1 (il-1) in sleep control and thermoregulation was evaluated. to this purpose, mdp and il-1 were injected intracerebroventricularly at dark onset into freely moving rats pretreated twice intraperitoneally with para-chlorophenylalanine (pcpa) (300 mg/kg), which depletes brain 5-ht and causes insomnia. fever and slow-wave sleep (sws) enhancement induced by 150 pmol mdp were completely blocked in pcpa- ... | 1997 | 9374807 |
| fos-like immunoreactivity in the circadian timing system of calorie-restricted rats fed at dawn: daily rhythms and light pulse-induced changes. | daily rhythms of pineal melatonin, body temperature, and locomotor activity are synchronized to the light-dark cycle (ld) via a circadian clock located in the suprachiasmatic nuclei (scn). a timed caloric restriction in rats fed at dawn induces phase-advances and further phase-stabilization of these rhythms, suggesting that the circadian clock can integrate conflicting daily photic and non-photic cues. the present study investigated the daily expression of fos-like immunoreactivity (fos-ir) and ... | 1997 | 9372223 |
| changes in rat sleep after single and repeated injections of the long-acting somatostatin analog octreotide. | somnogenic activity is attributed to both growth hormone (gh) and gh-releasing hormone (ghrh). the aim of our experiments was to study sleep after suppression of the somatotropic axis by means of administration of a long-lasting somatostatin analog, octreotide. rats received subcutaneous injections of physiological saline (baseline), octreotide (1, 10, and 200 microg/kg), or a control solution just before light onset, and sleep-wake activity and cortical brain temperature were recorded for 23 h. ... | 1997 | 9362315 |
| subdiaphragmatic vagotomy blocks the sleep- and fever-promoting effects of interleukin-1beta. | the mechanism by which peripheral cytokines signal the central nervous system to elicit central manifestations of the acute phase response remains unknown. recent evidence suggests that cytokines may signal the brain via the vagus nerve. to test this possibility, we examined sleep-wake activity and brain temperature (tbr) after the intraperitoneal administration of saline or three doses (0.1, 0.5, and 2.5 microg/kg) of interleukin-1beta (il-1beta) in subdiaphragmatically vagotomized (vx) and sha ... | 1997 | 9362287 |
| transient fluctuation of serum melatonin rhythm is suppressed centrally by vitamin b12. | vitamin b12 has been reported to improve sleep-wake rhythm disorders. although the mechanism is still unclear, a change in the sensitivity of the circadian clock system to photic input is thought to be a possible mechanism of the effect. in this study, the effect of the vitamin b12 on the circadian aspect of the electroretinogram (erg) and serum melatonin level was analyzed in rats. vitamin b12, alpha-(5,6-dimethylbenzimidazolyl)-co-methyl-cobamide was daily administrated subcutaneously for 8 we ... | 1997 | 9360022 |
| effect of intracerebroventricular administration of alpha-helical crh (9-41) on the sleep/waking cycle in rats under normal conditions or after subjection to an acute stressful stimulus. | it has been shown in a previous study that specific lesioning of the noradrenergic system of the locus coeruleus abolished the sleep increase induced by immobilization stress. given the fact that brain corticotropin-releasing hormone (crh) acts as a neurotransmitter in the locus coeruleus under stress conditions, the present study was designed to investigate the involvement of crh in the sleep increase seen after immobilization stress and on the spontaneous wake/sleep cycle. one hundred microgra ... | 1997 | 9358394 |
| modafinil induces wakefulness without intensifying motor activity or subsequent rebound hypersomnolence in the rat. | modafinil, a novel compound for treating excessive sleepiness, potently increases wakefulness in laboratory rodents, cats, monkeys and humans. although its mechanism of action is unknown, modafinil appears to be unlike classic stimulants. we investigated this generality by testing the selectivity of this compound for wake-promoting effects (e.g., relative to locomotor effects) and homeostatic sleep responses after drug-induced waking relative to the prototypical stimulant methamphetamine (meth). ... | 1997 | 9353396 |
| invasion of intestinal epithelia in vitro by the parasitic nematode trichinella spiralis. | studies of nematode establishment in intestinal niches has been hindered by the lack of a readily manipulated in vitro assay. in this report, experiments are described wherein the larval stage of the parasitic nematode trichinella spiralis was shown to invade epithelial cell monolayers in vitro. larvae penetrated cells and migrated through them, leaving trails of dead cells in their wake. cells derived from five different species were susceptible to invasion, reflecting the broad host range of t ... | 1997 | 9353069 |
| pontine microinjection of carbachol does not reliably enhance paradoxical sleep in rats. | it has been repeatedly shown in cats that acute administration of carbachol into the pontine reticular formation (prf) readily evokes a state that closely mimics natural paradoxical sleep (ps). surprisingly, there are few corresponding studies in rats. in order to further characterize the effects of pontine carbachol in rats, 151 injections of different doses (from 3 micrograms to 0.005 microgram in 0.1 microliter saline) of carbachol were made at different sites within the prf of 70 rats. sleep ... | 1997 | 9351126 |
| the hepatic perisinusoidal stellate cell. | hepatic stellate cell (also referred to as ito cell, fat-storing cell, perisinusoidal cell, lipocyte) is one of the sinusoid-constituent cells that play multiple roles in liver pathophysiology. although identification of the stellate cell had taken about 100 years because of the misconception caused by the discoverer von kupffer, wake made a great contribution to the "re" discovery of the cell in 1971. establishment of the isolation of hepatic non-parenchymal cells from rats by knook has made it ... | 1997 | 9302568 |
| stress-induced sleep deprivation modifies corticotropin releasing factor (crf) levels and crf binding in rat brain and pituitary. | electroencephalographic (eeg) studies have shown that corticotropin-releasing factor (crf) administration induces eeg activation, decreases sleep time both in rats and humans and modifies the sleep pattern in sleep deprived rats. in the present study we have investigated whether crf neuronal activity could be altered in a situation of disrupted sleep-wake cycle. sleep deprivation (sd) was induced by keeping the rat for 72 h on a small platform (7 cm) surrounded by water. immediately after the sd ... | 1997 | 9299209 |
| development of diurnal organization of eeg slow-wave activity and slow-wave sleep in the rat. | this study characterizes the development of diurnal patterns of slow-wave sleep (sws) distribution and sws electroencephalographic (eeg) delta-power (dp) density in 12- to 24-day-old rats (p12-p24). diurnal organization in sleep-wake distribution was established by p20. a decline in sws dp across the light phase did not appear until p24. before p20, sws dp increased across the light phase in a pattern inverse to that typically seen in adult rats. at p20, sws dp was evenly distributed across the ... | 1997 | 9277528 |
| antiserum to growth hormone decreases sleep in the rat. | to determine whether an acute withdrawal of growth hormone (gh) alters sleep, the effects of antiserum to gh (gh-as) on sleep were studied in the rat. sleep-wake activity and cortical brain temperature (tc) were recorded for 2 days after systemic injection of physiological saline. then, one group of rats (n = 6) received gh-as whereas another group of rats was injected with normal rabbit serum (n = 6). the injections were given 1 h before light onset, and the rats' behaviors were recorded for 23 ... | 1997 | 9258914 |
| comparison between conventional and neural network classifiers for rat sleep-wake stage discrimination. | this article describes an approach to selecting the most efficient classifier for rat sleep staging (waking, rem sleep and nrem sleep) discrimination. three conventional (bayesian, linear, and euclidean) and two neural network (multilayer perceptrons integrating or not integrating contextual information) classifiers were compared. for each classifier, performances were presented in the form of a statistical concordance matrix comparing classifier results versus human expert results on 6 24-hour ... | 1997 | 9246225 |
| high performance seizure-monitoring system using a vibration sensor and videotape recording: behavioral analysis of genetically epileptic rats. | a new seizure-monitoring apparatus containing a piezoceramic vibration sensor combined with videotape recording was developed. behavioral analysis of ihara's genetically epileptic rat (iger), which is a recently developed novel mutant with spontaneously limbic-like seizures, was performed using this new device. twenty 8-month-old male igers were monitored continuously for 72 h. abnormal behaviors were detected by use of a vibration recorder, and epileptic seizures were confirmed by videotape rec ... | 1997 | 9241637 |
| ccd-3693: an orally bioavailable analog of the endogenous neuroactive steroid, pregnanolone, demonstrates potent sedative hypnotic actions in the rat. | an endogenous neuroactive steroid, pregnanolone, and an orally available synthetic analog, ccd-3693, were administered to rats at the middle of their circadian activity phase (6 hr after lights off). electroencephalogram-defined sleep-wake states, locomotor activity and body temperature were concurrently measured 30 hr before and after treatment. identical procedures were used to test triazolam and zolpidem. triazolam (0.1-1.6 mg/kg), zolpidem (2.5-10 mg/kg) and the neuroactive steroids (10-30 m ... | 1997 | 9223583 |
| determination of nadh in the rat brain during sleep-wake states with an optic fibre sensor and time-resolved fluorescence procedures. | the present paper reports a nanosecond time-resolved fluorescence derived from the cortex and the area of the periaqueductal gray including the nucleus raphe dorsalis (pag-nrd) in unanaesthetized freely moving rats. the measurements were acquired through a single optic fibre transmitting a subnanosecond nitrogen laser pulse (337 nm, 15 hz) and collecting the brain fluorescence occurring at 460 nm which might depend on mitochondrial nadh (reduced form of nicotinamide adenine dinucleotide). the fl ... | 1997 | 9219933 |
| cardiopulmonary interactions following rem sleep deprivation in sprague-dawley rats. | we characterized the effects of 48 h of rapid-eye-movement (rem) sleep deprivation on cardiovascular and respiratory variables and on sleep-related cardiopulmonary interactions in adult male sprague-dawley rats. rats were instrumented for monitoring eeg, emg, and aortic blood pressure. respiratory rate and minute ventilation were measured by unrestrained single-chamber plethysmography. by using radiotelemetry to monitor blood pressure we clearly demonstrated progressive decreases in mean blood p ... | 1997 | 9217073 |
| effects of 72 hours sleep deprivation on wound healing in the rat. | the purpose of this study was to examine effects of sleep deprivation on cellular and biochemical markers of wound healing. expanded polytetrafluoroethylene tubing inserted in subcutaneous tissue created miniature wounds in the dorsal skin of 12 rats. seven days later, 6 rats were deprived of sleep by the platform method for 72 hr; control rats remained on usual sleep/wake routines. numbers of macrophages, granulocytes, fibroblasts, and extent of connective tissue present and total amounts of pr ... | 1997 | 9179179 |
| sleep in rats rendered chronically hyperprolactinemic with anterior pituitary grafts. | a hyperprolactinemic rat model [rats bearing anterior pituitary grafts under the capsule of the kidney (ap-grafted rats)] was used to study sleep-wake activity and cortical brain temperature (t(crt)). fisher 344 male rats (n = 24) were implanted with anterior pituitaries from rat pups; the control rats (n = 12) were sham-operated. sleep-wake activity and t(crt) were recorded for 2 days between weeks 3 and 7 after surgery. the hyperprolactinemic state of the rats was confirmed by plasma prolactin ... | 1997 | 9163548 |
| voltammetric detection of nitric oxide (no) in the rat brain: its variations throughout the sleep-wake cycle. | a sensor allowing the specific detection of nitric oxide (no) is reported. together with differential pulsed voltammetry, it allows the detection of a 650 mv signal either in no solutions or in the rat frontal cortex. the intraperitoneal (i.p.) administration of a no donor (s-nitrosoglutathione, 20 mg/kg i.p.) increases the signal height (+30%) while that of a nitric oxide synthase (nos) inhibitor like l-nitro-arginine-p-nitro-anilide (100 mg/kg i.p.), produces its complete disappearance in the ... | 1997 | 9159507 |
| interleukin-1 induces changes in sleep, brain temperature, and serotonergic metabolism. | simultaneous recordings of sleep-wake activity and of serotonergic metabolism in the medial preoptic area were performed in freely moving rats after the intracerebroventricular injection of interleukin-1 (il-1) at dark onset. il-1 (2.5 ng) induced a biphasic increase in slow-wave sleep and an early increase in serotonergic metabolism starting 30 min postinjection. phasic, state-specific changes (which have been described in spontaneous sleep) were superimposed on this tonic, overall increase in ... | 1997 | 9124484 |
| effect of vitamin b12 on the sleep-wake rhythm following an 8-hour advance of the light-dark cycle in the rat. | we have studied the effect of vitamin b12 (vb12) on the sleep-wake rhythm following an 8-h advance of the light-dark (ld) cycle in the rat. the electroencephalogram and electromyogram were recorded on chart paper via a two-channel telemetry system. infusion of vb12 (mecobalamin; 0.25 microgram/h) or saline into the abdominal cavity was performed using an implanted miniosmotic pump. before the phase shift, there was no significant difference between the two groups in terms of the mean daily amoun ... | 1997 | 9108574 |
| thermosensitive neurons of the diagonal band in rats: relation to wakefulness and non-rapid eye movement sleep. | the thermosensitivity of the neurons in the diagonal band of broca (dbb) was studied in 12 freely moving rats by determining responses to local cooling or warming with a water perfused thermode. of 151 neurons studied, 37 (25%) neurons met the criterion for thermosensitivity including 17 warm-sensitive (wsns) and 20 cold-sensitive neurons (csns). the spontaneous discharge rates of wsns and csns were recorded through 1-3 sleep-waking cycles. the discharge of wsns and csns during waking and non-ra ... | 1997 | 9106443 |
| effects of venlafaxine in the sleep architecture of rats. | different venlafaxine doses (1, 5, and 10 mg/kg) and saline solution were administered to ten male wistar rats (latin-square design). compared with saline, venlafaxine produced a dose-related suppression of rem sleep and an increase in wake time while slow wave sleep was reduced. this effect is similar to the one that has been reported with some tricyclic antidepressants. | 1997 | 9084070 |
| changes in sleep architecture following chronic mild stress. | chronic exposure to mild unpredictable stress causes subsensitivity to rewards (anhedonia). these effects are reversible by chronic treatment with antidepressant drugs, and have been proposed as an animal model of depression. in the present study, sleep architecture, particularly the rapid eye movement (rem) component, was mapped in rats following exposure to chronic mild stress. the study used a unique large scale automated sleep system to record and analyze the sleep signals from 32 rats simul ... | 1997 | 9034536 |
| high-frequency gamma electroencephalogram activity in association with sleep-wake states and spontaneous behaviors in the rat. | the occurrence of high-frequency gamma activity (30-60 hz) and its relationship to other frequency band activities were examined by spectral analysis of the electroencephalogram in association with sleep wake states and spontaneous behaviors in the rat. in the electroencephalogram, gamma wave activity was evident in unfiltered and high-frequency filtered recordings, in which it was prominent during attentive or active wake episodes and during paradoxical sleep, when theta-like activity was also ... | 1997 | 9015337 |
| nitric oxide production in rat thalamus changes with behavioral state, local depolarization, and brainstem stimulation. | since its discovery as a putative neurotransmitter in the cns, several functional roles have been suggested for nitric oxide (no). however, few studies have investigated the role of no in natural physiology. because no synthase (nos) has been localized in regions believed to be important for attention and arousal, we hypothesized that no production would be state-dependent. to test this hypothesis, we used in vivo microdialysis, coupled with the hemoglobin-trapping technique, to monitor extracel ... | 1997 | 8987767 |
| non-rapid eye movement sleep is suppressed in transgenic mice with a deficiency in the somatotropic system. | sleep-wake activity was studied in a transgenic mouse model (th-hgh) with a deficiency in the somatotropic axis (growth hormone (gh)-releasing hormone (ghrh)-gh-insulin-like growth factor-i (igf-i)). this dwarf transgenic mouse strain expresses a human gh (hgh) reporter gene linked to 4.8 kb of the rat tyrosine hydroxylase flanking sequence, targeting the production of hgh to sites of tyrosine hydroxylase synthesis in the brain. endogenous gh and igf-i are suppressed in these mice, as well as gh ... | 1996 | 8981482 |
| continuous recordings of brain regional circulation during sleep/wake state transitions in rats. | continuous measurement of regional blood flow (rbf) in the brain of a freely behaving rat was attained by a combination of laser-doppler (ld) flowmetry and our originally devised apparatus, which had been developed for the automatic releasing of the twisting of lines connected between experimental apparatus and the freely behaving animal. rbf changes were studied in a ventral region of the rostral basal forebrain along with sleep-wake states. when compared with the rbf level during slow-wave sle ... | 1996 | 8967416 |
| the effects of ozone exposure on the sleep-wake cycle and serotonin contents in the pons of the rat. | polysomnographic studies were done at hourly intervals during 0.00, 0.35, 0.75 and 1.50 ppm of ozone (o3) exposure. we found a significant decrease in paradoxical sleep after 2 h and an increase in slow wave sleep after 12 h at all concentrations of o3. high resolution liquid chromatography demonstrated an increase in 5-ht concentration in the rat pons, in a roughly stepwise fashion as the o3 concentration increased. we propose that reaction products derived from o3 exposure, such as prostagland ... | 1996 | 8929975 |
| automation of data acquisition and of experiment control: application to the study of sleep-wake cycles and behavioral paradigms]. | the low cost of microcomputers allows them to be dedicated full time to data acquisition and analysis of experimental paradigms. the usual interfaces required for such interaction with the experiment are briefly explained, namely, analog-to-digital converters, input-output control lines and real time clocks. some basic concepts on the use of microcomputers for the automation of data acquisition and control are summarized, including the characterization of waveshapes, the structure of data storag ... | 1986 | 8929083 |
| human immunodeficiency virus envelope glycoprotein 120 alters sleep and induces cytokine mrna expression in rats [published errata appear in am j physiol 1996 aug;271(2 pt 2):section r following table of contents and 1996 dec;271(6 pt 3):section r following table of contents]. | sleep is altered during the course of viral infection, including that in which the human immunodeficiency virus (hiv) is the etiologic agent. alterations in the sleep of hiv-infected individuals occur early in the course of infection, prior to the onset of aids. the mechanisms for such alterations in sleep are not known. the hiv envelope glycoprotein 120 (gp120) induces the synthesis and secretion of cytokines that enhance [e.g., interleukin (il)-1 and tumor necrosis factor] and suppress (e.g., ... | 1996 | 8928927 |
| midlatency auditory evoked potentials and the startle response in the rat. | the p13 midlatency auditory evoked potential in the rat is (i) sleep state dependent, (ii) undergoes rapid habituation and (iii) is blocked by the cholinergic antagonist scopolamine. as such, the p13 potential in the rat shows the same characteristics as the p1 (or p50) potential in the human. these potentials are thought to be mediated, at least in part, by the cholinergic arm of the reticular activating system. previous studies have linked the reticular activating system with the startle respo ... | 1996 | 8923542 |
| brain capillary perfusion during sleep. | brain capillary perfusion was evaluated in the different states of the wake-sleep cycle-quiet wakefulness (qw), quiet sleep (qs), and active sleep (as)-in rats. the extent of the perfused capillary network was determined by intravascular distribution of a fluorescent marker. evans blue (eb); it remained unchanged across the three behavioral conditions, qw, qs, and as. the anatomical network was assessed by alkaline phosphatase (ap) endothelial staining, which is known to underestimate the number ... | 1996 | 8898706 |
| pregnancy-associated sleep changes in the rat. | sleep disorder during the course of pregnancy has been recently recognized in humans. however, the underlying mechanism of pregnancy-associated sleep disorder remains undetermined, and sleep changes even during normal pregnancy have not been fully understood. to describe the effects of pregnancy on sleep, sleep-wake patterns before and after fertile mating were compared in an animal model. baseline recordings of sleep and brain temperature were made throughout a normal 4-day estrous cycle in fem ... | 1996 | 8898001 |