Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| vasoactive intestinal polypeptide neuron changes in the senile rat suprachiasmatic nucleus. | the suprachiasmatic nucleus (scn) is thought to be the main neuronal oscillator underlying circadian rhythmicity of different biological phenomena such as sleep-wakefulness and body temperature. although numerous studies in old rats showed that circadian organization is clearly disturbed in senescence, no decrease in total scn cell number has been observed. however, in an earlier study we found a significant decrease of approximately 30% in the number of immunocytochemically-stained vasopressin ... | 1988 | 3398995 |
| sleep fragmentation in the arthritic rat. | we examined the diurnal sleep-wake patterns in the adjuvant arthritic rat. in contrast to control rats, arthritic rats lacked a normal diurnal variation in sleep and wakefulness. thus, arthritic rats exhibited no differences in the mean number or duration of bouts of sleep and episodes of wakefulness between light and dark hours. arthritic rats also had a marked increase in the fragmentation of their sleep manifested by an increased number of sleep bouts and episodes of wakefulness and a decreas ... | 1988 | 3405623 |
| effect of peripheral administration of arginine vasotocin on neonatal sleep in rats. | vasotocin was recently reported to increase the neonatal amount of active sleep in kittens. in this study we examined the effects of arginine vasotocin (vasotocin), given intraperitoneally and at a wide dose range, on the sleep-wake behavior of 7-day-old and 14-day-old rat pups using a static charge sensitive recording system. it increased the percentage of quiet state relative to total sleep time at the doses of 0.01-1.0 ng/g of body weight but did not affect it at the dose of 0.001 ng/g. the p ... | 1988 | 3420009 |
| desensitization of adenosine a2 receptors in the striatum of the rat following chronic treatment with diazepam. | following prolonged treatment (7 days) with diazepam (10 mg/kg/day, using alzet mini-osmotic pumps) in rats, the function of adenosine receptors was assessed in specific structures of the brain, using both agonist ligand binding and adenylate cyclase assays. binding to a1 receptors was quantified using [3h]n6-[(r)-1-methyl-2-phenylethyl] adenosine, a selective ligand at a1 receptors. differences in the binding of this ligand and that of [3h]5'-n-ethylcarboxamide adenosine, which binds to both a1 ... | 1988 | 2849727 |
| sleep state-specific neuronal activity in rat dorsal lateral geniculate nucleus is not altered by local serotonin and norepinephrine depletion. | the relay cells in dorsal lateral geniculate nucleus (dlgn) represent one among many populations of neurons throughout the neuraxis that display systematic alteration of spontaneous rate and pattern of discharge concurrent with change in state of arousal. both noradrenergic (ne) and serotonergic (5-ht) systems innervate dlgn and are implicated in sleep-wake control mechanisms. our study was designed to test the influence of these systems upon sleep state-related multiple unit activity in the dlg ... | 1989 | 2494051 |
| [role of hypothalamic adenosinergic systems in regulating states of wakefulness in the rat]. | immunohistochemical localization of adenosine deaminase (ada), marker for the putative neurotransmitter/neuromodulator adenosine, has revealed a population of ada-positive neurons in the ventrolateral hypothalamus in the rat brain. these posterior neurons possess adenosine uptake sites. we have studied the effects of local injections of adenosinergic drugs on the sleep-wake cycle in the rat. microinjection of erythro-9-(hydroxy-2, nonyl-3) adenine (ehna), a specific inhibitor of adenosine deamin ... | 1989 | 2499406 |
| [the effect of valproic acid on sleep structure and ethanol consumption in rats with various types of individual reactivity before and after stress exposure]. | the influence of valproic acid on sleep structure and alcohol motivation was studied in pretyped rats prior and following rem sleep deprivation. during eeg recording of wake-sleep cycle valporoic acid was shown to produce hypnotic action dependent on drug dosage in high active and low active animals. there was also shown that following rem sleep deprivation low active animals significantly reduced ethanol consumption under valproic acid influence. it seems likely from the results obtained that v ... | 1989 | 2514811 |
| the influence of the light-dark and wake-sleep cycles on preoptic camp concentration in the rat. | the concentration of camp was measured in the preoptic region of rats sleeping at normal laboratory conditions (12:12 h ld, ta 22 +/- 0.5 degrees c). the results show that the nucleotide concentration changed both during the circadian ld cycle and during the ultradian wake-sleep cycle. | 1989 | 2547403 |
| the effect of propranolol on camp concentration in the rat preoptic region during the wake-sleep cycle. | in control conditions preoptic camp concentration during wakefulness was significantly higher than during synchronized sleep. no differences in nucleotide concentration were observed in the cerebral cortex. propranolol decreases brain camp concentration. this change was associated with the suppression of the difference observed between wakefulness and synchronized sleep in the preoptic region. | 1989 | 2547404 |
| the cholinergic influence upon rat dorsal lateral geniculate nucleus is dependent on state of arousal. | several lines of evidence suggest a role for acetylcholine (ach) in mediating the effects of state of arousal on transfer of visual information through the lateral geniculate nucleus (lgn). local application of cholinergic agonists to geniculate relay cells in anesthetized cats and rats produces predominantly facilitatory effects. this indicates that presynaptic release of ach may be responsible for the increased excitability of lgn relay cells that is observed during waking and rem sleep. in th ... | 1989 | 2570623 |
| effects of sex, thyro-parathyroidectomy, and light regime on levels and circadian rhythms of wheel-running in rats. | intact and thyro-parathyroidectomized (tpx) sprague-dawley rats of both sexes were observed for 24 days under a 12:12 light:dark cycle (entrainment), followed by 20 days in constant dim red light (free-run). circadian periods and levels of wheel-running activity were examined. intact females and tpx males were significantly more active and had significantly shorter free-running circadian periods than intact males, and the effects of tpx in females were different from those in males. circadian pe ... | 1989 | 2623053 |
| changes in vasopressin neurons and fibers in aging and alzheimer's disease: reversibility in the rat. | the neuropeptide vasopressin (vp) is released from the neurohypophysis into the circulation where it acts as antidiuretic hormone on the kidney. in addition, vp is present in nerve cells and fibers in several areas in the rodent and primate brain where it acts as a neurotransmitter or neuromodulator. in the human brain a marked decrease in total cell number and vp cell number was observed in senescence in the suprachiasmatic nucleus, the hypothalamic nucleus regulating circadian rhythms. this de ... | 1989 | 2690091 |
| decreased slow-wave and paradoxical sleep in a rat chronic pain model. | diurnal sleep-wake patterns in the normal and the adjuvant arthritic rat were measured during the first 3 h of both light and dark periods. during the hours of maximal sleep in the normal rat, arthritic rats showed a significant increase in wakefulness (wake), a shift to non-rapid-eye-movement (nrem) stages with lower amplitudes (ls and hs1), and a large reduction of nrem sleep with the highest-amplitude (hs2) and paradoxical sleep. arthritic rats also showed marked sleep fragmentation manifeste ... | 1989 | 2711092 |
| awaking effect of prostaglandin e2 in freely moving rats. | the awaking effect of prostaglandin (pg) e2 was further examined in a long-term bioassay system. pge2 in saline solution was infused between 11.00 and 17.00 h at 0.1, 1, 10, and 100 pmol/min (infusion volume 10 microliters/h) into the third cerebral ventricle of freely moving rats. these rats were otherwise infused with saline continuously and exhibited a circadian cycle, spending 70% of the daytime and 37% of the night in sleep. in the rats that received pge2 infusion at 1, 10, and 100 pmol/min ... | 1989 | 2720378 |
| suppressant effects of selective 5-ht2 antagonists on rapid eye movement sleep in rats. | the effects of the novel, highly selective serotonin-2 (5-ht2) antagonists, ici 169,369 and ici 170,809, on 24 h eeg sleep-wake activity were studied in the rat. both compounds caused a dose-related increase in the latency to rapid eye movement sleep (rems) and significantly suppressed cumulative rems time up to 12 h postinjection. in contrast, neither drug disrupted slow-wave sleep continuity in as much as the latency to non-rems (nrems) and cumulative nrems time were unchanged. however, at the ... | 1989 | 2720415 |
| neurobehavioral teratogenic effects of clomipramine and alpha-methyldopa. | neonatal treatment of rats with centrally acting drugs such as clomipramine was shown to affect adult body and brain weight, behavior and sleep. we made a further study of the effects of clomipramine and tested one dose of alpha-methyldopa. male rats were treated twice daily with saline, 7.5 or 15 mg/kg clomipramine or 100 mg/kg alpha-methyldopa from postnatal day 2-14 and tested in adulthood for effects on acquisition of radial maze behavior, on problem solving behavior in hebb-williams mazes, ... | 1989 | 2725445 |
| evidence that brain prostaglandin e2 is involved in physiological sleep-wake regulation in rats. | we reported in previous studies that prostaglandin e2 (pge2) has central effects of augmenting wakefulness and suppressing slow-wave sleep (sws) and paradoxical sleep (ps) in rats. in the present study, we tested the effect of ah 6809, an antagonist of pge2 receptors, on sleep-wake activities. ah 6809 in saline was infused continuously into the third ventricle of freely moving rats at a rate of 2.1, 6.3, and 21 pmol/min from 2300 to 0500 hr. during the infusion at 21 pmol/min, wakefulness decrea ... | 1989 | 2748610 |
| prolactin, vasoactive intestinal peptide, and peptide histidine methionine elicit selective increases in rem sleep in rabbits. | the purpose of these experiments was to determine whether (1) vasoactive intestinal peptide (vip) produces effects on rabbit sleep similar to those reported for rats and cats; (2) peptide histidine methionine (phm), a peptide closely related to vip, mimics the sleep effects of vip; and (3) pituitary prolactin (prl), a pituitary hormone that has a sleep-related secretory pattern and for which vip and phm act as releasing factors, has similar effects on sleep. vip or phm (0.01, 0.1 and 1.0 nmol/kg ... | 1989 | 2765864 |
| [brucella clearance as a sensitive method for the detection of cross reactions of brucella abortus with yersinia enterocolitica 03, 06, 09 and salmonella urbana and salmonella abony]. | determination of the brucella clearance rate has proved to enable assessment of brucella immune reaction in rat, even after vaccination with yersiniae and salmonellae. vaccination with yersinia (y.) enterocolitica o6 and o9 produced 95 per cent of "high responders", whereas 65 per cent of "high responders" and 25 per cent of "non-responders" were recorded in the wake of o3. salmonella (s.) urbana vaccination gave 50 per cent of "high responders" and 27 per cent of "non-responders", while 100 per ... | 1989 | 2774825 |
| metabolic diversions in the oxidative metabolism of hepatic and neuronal systems of rat (wistar strain) under induced benthiocarb stress. | metabolic diversions in oxidative metabolism of hepatic and neuronal systems of rat were noticed during induced benthiocarb stress. the inhibition of dehydrogenases indicates disturbed mitochondrial integrity, and reduction in cytochrome-c-oxidase suggests possible respiratory distress. the drop in atpases and pnppase indicates the prevalence of energy crisis. the increased specific activities of nadp+ dependent dehydrogenases suggests augmented lipid biosynthesis in the wake of impaired oxidati ... | 1989 | 2818608 |
| alpha-interferon modifies cortical eeg activity: dose-dependence and antagonism by naloxone. | activation of the immune system is believed to provide signals in the form of chemical messengers that are able to change neural activity in a variety of regions of the central nervous system. in studies designed to examine the effects of alpha-interferon (alpha-ifn) upon the central nervous system, recordings of cortical eeg were made following intracerebroventricular injection of various doses of the cytokine. administration of 25 u of alpha-ifn increased the amount of wake and decreased the a ... | 1990 | 1965206 |
| sleep variables are unaltered by zolantidine in rats: are histamine h2-receptors not involved in sleep regulation? | the effects of the h1-receptor antagonist diphenhydramine and the brain-penetrating h2-receptor antagonist zolantidine were studied in rats implanted for chronic sleep recordings. diphenhydramine (1.0-4.0 mg/kg) significantly increased slow wave sleep and decreased wakefulness. zolantidine (0.25-8.0 mg/kg) had no significant effects on any of the sleep parameters examined. one possibility is that zolantidine did not enter the brain in sufficient concentration to produce significant changes on sl ... | 1990 | 1977498 |
| proopiomelanocortin (pomc)-derived peptides and sleep in the rat. part 1--hypnogenic properties of acth derivatives. | the sleep-wake effects of the proopiomelanocortin (pomc)-derived peptides, i.c.v. injected, are reported. adrenocorticotropic hormone (acth, 1 microgram) induces an awakening effect, while its two derivatives, desacetyl-alpha-msh (des-alpha-msh, 1ng) and corticotropin-like intermediate lobe peptide (clip, 10 ng), are respectively able to increase slow wave sleep (sws) and paradoxical sleep (ps); the hypnogenic effect of clip is also observed in hypophysectomized rats. furthermore, two hypothalam ... | 1990 | 1981927 |
| the in vivo and in vitro activity of ahr-13268d, a new antiallergic/antihistaminic agent. | ahr-13268d (4-[3-[4-[bis(4-fluorophenyl)hydroxymethyl]-1- piperidinyl]propoxy]benzoic acid, sodium salt) is a potent, long-acting water soluble, antiallergic and antihistaminic agent. ahr-13268d protects sensitive guinea pigs from collapse induced by aerosolized antigen; 1, 5, and 24 h ed50s in the test were 0.27, 0.25, 0.93 mg/kg, po, respectively. ahr-13268d was also active when given as an aerosol, the 1 h ed50 = 0.29%. in the rat passivefoot anaphylaxis test. ahr-13268d was slightly more act ... | 1990 | 1982201 |
| rates of cerebral protein synthesis are linked to slow wave sleep in the rat. | using l-[1-14c]leucine autoradiography, rates of cerebral and local cerebral protein synthesis were studied during wakefulness, slow wave sleep (sws) and rem sleep in the rat. in the cerebrum as a whole, the rate at which labelled leucine was incorporated into tissues was positively correlated with the occurrence of slow wave sleep. we failed to observe a significant correlation of protein synthesis rate with either wakefulness or rem sleep. as in the cerebrum as a whole, most discrete brain reg ... | 1990 | 2082375 |
| effects of alternating 45-min light-dark cycles on sleep in the rat. | we studied the effect of alternating 45-min light-dark (l-d) cycles on sleep in rats. introduction of short l-d cycles did not abolish the normal circadian rhythm of sleep-wake activity. the amount of non-rem sleep was however increased in the l and decreased in the d 45-min periods. rem was promoted in the d and inhibited in the l 45-min periods. the influence of l-d or d-l transitions depended on the sleep wake activity immediately before the transition. | 1990 | 2100102 |
| sleep during acute dopamine d1 agonist skf 38393 or d1 antagonist sch 23390 administration in rats. | the effect of the d1 dopamine (da) receptor agonist skf 38393 was compared with that produced by the d1-receptor antagonist, sch 23390, in rats implanted with electrodes for chronic sleep recordings. skf 38393 (0.1 to 4.0 mg/kg) significantly suppressed rapid-eye-movement sleep (rems) after the highest dose. sch 23390 (0.1 to 2.0 mg/kg) increased slow-wave sleep (sws), whereas wakefulness (w) and rems were decreased. pretreatment with skf 38393 (0.5 mg/kg) prevented the effects of sch 23390 (0.2 ... | 1990 | 2141985 |
| chloramphenicol modifies benzodiazepine receptor rhythm in the pontomesencephalic formation of the rat. | pontomesencephalic benzodiazepine (bz) receptors were measured at 4 h intervals throughout a 24 h day, and compared with those in frontal cortex, using [3h]diazepam binding. animals were treated with saline, chloramphenicol (cap) or thiamphenicol (tap). an ultradian rhythm of receptors was observed in both cases, which was abolished by cap but not by tap. saturation curves and scatchard analysis indicated decreased binding was due to a decrease in the number of receptors. cap effect on rem sleep ... | 1990 | 2165436 |
| the short-term effects of dl-propranolol on the wake-sleep cycle of the rat are related to selective changes in preoptic cyclic amp concentration. | the short-term effects of the intraperitoneal administration of dl-propranolol on the wake-sleep cycle of the rat were studied in relation to the cyclic amp concentration in the preoptic region and cerebral cortex. the results show that propranolol, but not saline, affected all stages of the wake-sleep cycle, increasing wakefulness, decreasing synchronized sleep and abolishing desynchronized sleep. these effects were associated with a decrement in cyclic amp concentration both in wakefulness and ... | 1990 | 2168318 |
| [changes in the oxygen tension level in different brain structures of rats in the waking-sleep cycle]. | changes of oxygen tension level (po2) in the visual cortex, dorsal hippocampus, lateral hypothalamus and central grey substance were studied during wake-sleep cycle in rats. the dependence was established of po2 level changes on the character of behavioural reactions and on the accompanying hippocampal eeg activity: during orienting-investigatory and active defensive behaviour and also during paradoxical sleep, accompanied by hippocampal theta rhythm, po2 level increased; during passive-defensiv ... | 1990 | 2169159 |
| relationship between camp concentration in anterior hypothalamic-preoptic region and the ultradian wake-sleep cycle. | in the rat anterior hypothalamic-preoptic region adenosine 3':5'-cyclic monophosphate concentration changes during the ultradian wake-sleep cycle. the administration of dl-propranolol and the exposure to low ambient temperature decreased the nucleotide concentration and also modified the wake-sleep cycle. this suggests that in this region a biochemical correlation exists with different functional states. | 1990 | 2170491 |
| responsiveness of rats to interleukin-1: effects of monosodium glutamate treatment of neonates. | monosodium glutamate (msg) treatment of neonatal rats results in degenerative lesions of the medial basal hypothalamus, particularly the arcuate nucleus (an). the an is rich in corticotropin-releasing hormone (crf) and adrenocorticotrophic hormone/alpha-melanocyte-stimulating hormone (alpha-msh). these substances are part of a negative feedback mechanism for the regulation of interleukin-1 (il1), a cytokine with diverse biologic actions including a role in sleep regulation. the purpose of these ... | 1990 | 2176294 |
| sensitivity of eeg in young rats to toluene exposure. | effects of toluene on the electroencephalogram (eeg) and its power spectra were measured during a 2-hr exposure in a dynamic inhalational chamber in young rats (30-53 days old) and compared to those in adult rats (63-77 days old). rats were exposed to one of the three concentrations [low (108-111 ppm), medium (160-163 ppm), and high (407-432 ppm)] of toluene on different days. in tests on sleep-wake cycle, in the young animals the duration of the wake stage (w) was increased with decreases of ra ... | 1990 | 2217506 |
| effect of repeated application of nootropic drugs on sleep in rats. | the effects of repeated application of nootropic drugs on the sleep-wake cycle were investigated in rats. piracetam, meclofenoxate and pyritinol were injected intraperitoneally, 100 mg/kg per day, during a period of 10 days. the sleep-wake cycle was recorded each day between 8 a.m. and 4 p.m. repeated administration of piracetam and meclofenoxate led to an increase of the paradoxical sleep, a decrease of waking, and a very small increase of slow-wave sleep. pyritinol, on the other hand, decrease ... | 1990 | 2271011 |
| [prostaglandin e2 and d2: opponents in the regulation of the sleep-wake rhythm?]. | 1990 | 2304416 | |
| development of a computer program classifying rat sleep stages. | we developed a simple and precise program for the on-line judgement of the sleep stages of four rats simultaneously for an unlimited period, using a commercially available general purpose signal processor (nec-sanei 7t17; 32-bit, 5 mhz, 4 mbyte, 1 mbyte 1 floppy disc drive). eeg and emg were recorded with an 8-channel polygraph (nec-sanei, system 380) through electrodes chronically implanted into the brain. the signals were a/d converted every ms and integrated for 2760 ms after full-wave rectif ... | 1990 | 2319814 |
| hypoxia-induced sleep disturbance in rats. | the effects of varying degrees of hypoxia on sleep-wake organization were studied in rats prepared for chronic electrophysiological recording. the influence of piracetam (75, 50, and 500 mg/kg, i.p.) and hydergine (0.5, 1, and 3 mg/kg, i.p.) on sleep-wake organization in 10.5% oxygen was also investigated. the sleep-wake organization of rats under the effect of 15.5% oxygen content was unchanged, compared to that of normoxic control. more extreme hypoxia (12.6 and 10.5% oxygen) produced dramatic ... | 1990 | 2356393 |
| glutathione-s-transferase, superoxide dismutase, xanthine oxidase, catalase, glutathione peroxidase and lipid peroxidation in the liver of exercised rats. | glutathione-s-transferase (gst), superoxide dismutase (sod), xanthine oxidase, selenium-dependent glutathione peroxidase (gpxi), catalase activities and malondialdehyde (mda) content were determined in liver of three groups of exercised rats (e) viz., one day (e1), 10 days (e10) and 60 days (e60). gst, sod and xanthine oxidase activities increased significantly with the increase in exercise period. lipid peroxidation, expressed in terms of mda formation, also increased in the liver of all the th ... | 1990 | 2386536 |
| effects of t cycles of light/darkness and periodic forced activity on methamphetamine-induced rhythms in intact and scn-lesioned rats: explanation by an hourglass-clock model. | in this study intact and suprachiasmatic nuclei (scn)-lesioned female rats were treated with chronic methamphetamine (ma) via the drinking water. body temperature, feeding, drinking and wheel-running activity were continuously and automatically recorded. the rats were subjected to light-dark (ld) cycles with period t = 23 hr for 4 months and subsequently t = 25 hr for 3 months. daily 3-hr forced activity (fa 3:21) was imposed during a few weeks under both ld regimes. ma induced infradian rhythms ... | 1990 | 2388949 |
| propagation and collision characteristics of calcium waves in rat myocytes. | in myocytes, local contractions occur spontaneously and propagate as traveling waves. we observed the waves in myocytes as local changes in fura-2 fluorescence and determined some characteristics of the wave. myocytes were enzymatically isolated from rat left ventricles and incubated with 2 microm fura-2/am for 60 min. microscopic fluorescence images of myocytes were recorded with a high-sensitivity video camera. the images were digitally analyzed, frame by frame, and temporal changes in local f ... | 1990 | 2396699 |
| ultradian and circadian changes in the camp concentration in the preoptic region of the rat. | the concentration of adenosine 3',5'-cyclic monophosphate was measured, during the wake-sleep cycle, in the preoptic region and the cerebral cortex of rats kept in normal laboratory conditions (ambient temperature 22 +/- 0.5 degrees c, 12 h:12 h light-dark cycle) and, during wakefulness, in the preoptic region of rats exposed to extended light and dark periods (i.e. dark in the light hours of the normal photoperiod, and light in the dark hours of the normal photoperiod). the results show that th ... | 1991 | 1655158 |
| cholinergic modulation of responses to glutamate in the thalamic reticular nucleus of the anesthetized rat. | neurons in the thalamic reticular nucleus (trn) of the chloral hydrate-anesthetized rat were studied with extracellular recording and microiontophoretic application of cholinergic agents. in most cases (63%), the ejection of the agonist, carbachol, had no observable effect on spontaneous activity, and in an additional 33% of cases was observed to inhibit discharge rate. carbachol ejections with identical current and duration parameters proved capable of antagonizing the uniformly facilitatory re ... | 1991 | 1684131 |
| spike-wave discharges and sleep-wake states in rats with absence epilepsy. | the occurrence of spike-wave discharges was studied in relation to the daily fluctuations of vigilance level in rats. eight rats of the wag/rij strain, an animal model for idiopathic generalized epilepsy of the absence type, which were equipped with cortical eeg and nuchal emg electrodes, served as subjects. it was found that spike-wave discharges predominantly occur during light slow wave sleep and passive wakefulness. rem sleep, active wakefulness, and deep slow wave sleep are less susceptible ... | 1991 | 1743184 |
| cholecystokinin promotes sleep and reduces food intake in diabetic rats. | it has been reported that systemic injections of cholecystokinin (cck) elicit the behavioral characteristics of satiety, including sleep, in rats. cck is a potent stimulator of insulin secretion, and insulin is hypothesized to be involved in sleep and feeding regulation. the purpose of the current experiments was to study the possible role of endogenous insulin in the food-intake-reducing and hypnogenic effects of intraperitoneally (ip) administered cck. normal and streptozotocin (str)-diabetic ... | 1991 | 1745688 |
| serotonin and behavior: emphasis on motor control. | electrophysiologic studies of brain serotonergic neurons in behaving animals indicate that their activity is closely related to the sleep-wake-arousal cycle and to certain specific types of repetitive motor activity. a variety of other environmental and physiologic manipulations are ineffective in altering the activity of this neurochemical system. an attempt is made to relate these results to well-known involvement of brain serotonin in human affective disorders. | 1991 | 1752856 |
| intraperitoneal injection of cholecystokinin elicits sleep in rabbits. | cholecystokinin (cck) reduces food intake and promotes non-rapid-eye-movement sleep (nrems) in rats. the purpose of present experiments was to determine if cck is somnogenic in rabbits; another species in which cck suppresses feeding. white new zealand rabbits were treated intracerebroventricularly (icv; 0.05, 0.5 and 2 micrograms) or intraperitoneally (ip; 2.5, 10 and 40 micrograms/kg) with cck or saline, and sleep-wake activity and brain temperature (tbr) were recorded for 6 h. injections of 1 ... | 1991 | 1798781 |
| triazolam-induced sleep in the rat: influence of prior sleep, circadian time, and light/dark cycles. | rats entrained to 12-h on /12-h off light schedule and injected with triazolam 0.4 mg/kg at the mid-point of their activity phase (6 h after lights out: circadian time = ct-18) had a stronger hypnotic response than animals free-running in constant dark injected at the equivalent circadian time. in contrast, entrained rats injected 5 h after lights on (ct-5) showed increased wake after injection relative to baseline, largely due to rem sleep inhibition. hypnotic efficacy was found to be inversely ... | 1991 | 1798833 |
| sleep-wake regulation by pgd2 and e2. | 1991 | 1825402 | |
| the role of 5-hydroxytryptophan (5-htp) in the regulation of the sleep/wake cycle in parachlorophenylalanine (p-cpa) pretreated rat: a multiple approach study. | in the rat, the insomnia which follows the administration of parachlorophenylalanine (p-cpa), a serotonin synthesis inhibitor, is transiently reversed either by intra-cisternal injection of l-5-htp or by an associated injection of 5-htp and an l-aromatic-acid-decarboxylase inhibitor (benserazide). histochemical, immunohistochemical and chemical investigations showed that 5-htp administration does not lead to a detectable increase in cerebral 5-ht. these findings suggest that the restoration of s ... | 1991 | 1836762 |
| absence epilepsy and the level of vigilance in rats of the wag/rij strain. | in man, a relationship exists between sleep-wake states and absence epilepsy. during wakefulness, spike-wave discharges predominantly occur when the level of vigilance is not high, while during sleep they have a preference to occur during slow-wave sleep. during this latter type of sleep, spike-wave discharges prevail in periods where slow-wave sleep is light. in a series of experiments, the wag/rij rat model for absence epilepsy was characterized with respect to the relationships between the le ... | 1991 | 1906586 |
| molecular mechanisms of sleep-wake regulation: roles of prostaglandins d2 and e2. | although sleep-wake cycles are repeated every day and night and almost one-third of our lifetime is spent sleeping, the molecular mechanisms of sleep-wake regulation have remained little understood. recent experimental evidence indicates that prostaglandins (pg) d2 and e2 are probably two of the major endogenous sleep-regulating substances, one promoting sleep and the other wakefulness, in rats, dogs, rabbits, monkeys, and probably in humans as well. preliminary evidence indicates that the sites ... | 1991 | 1907936 |
| differential effects of m2 and m3 muscarinic antagonists on the sleep-wake cycle. | to study the role of muscarinic receptor subtypes in sleep control, methoctramine (25, 50, 75 micrograms), a highly selective m2 antagonist, was injected intra-cerebroventricularly into freely moving rats. methoctramine induced a dose-dependent increase in desynchronized sleep (ds) latency (from 62.7 +/- 10 min following saline to 122.4 +/- 13.8 min with the lowest dose) and a 75% decrease in the amount of ds in 6 h recordings. 4damp (a m3/m1 selective antagonist) did not significantly change ds ... | 1991 | 1912471 |
| inhibition of sleep in rats by inorganic selenium compounds, inhibitors of prostaglandin d synthase. | prostaglandin (pg) d2 has been postulated to be an endogenous sleep-promoting factor in rats, and secl4 and na2seo3 recently have been shown to inhibit the pgd synthase (prostaglandin-h2 d-isomerase, ec 5.3.99.2) activity of rat brain. the effect of these selenium compounds on sleep-wake activities was examined in freely moving rats along with their effects on brain temperature, food and water intake, and behavior. test substances were administered for 6 hr into the third ventricle of rats, usin ... | 1991 | 1924366 |
| sleep changes induced by the local application of 5,7-dihydroxytryptamine into the nodose ganglia and aortic denervation in the rat. | the effects of a bilateral microinjection of 5,7-dihydroxytryptamine (5,7-dht) into the nodose ganglia and aortic denervation on the daily amounts of sleep/wake states were studied in rats. both lesions produced an increase in paradoxical sleep and provoked the onset of paradoxical sleep episodes without slow-wave-sleep transition ("narcolepsy-like" paradoxical sleep episodes). the increase in paradoxical sleep observed after 5,7-dht injection was more important than that of the aortic denervati ... | 1991 | 1945758 |
| behavioural characteristics of sleep in rats under different light/dark conditions. | in the light, rats tend to sleep with curled-up body and closed eyes, while in the dark they tend to sleep more stretched out and often with open eyes. these differences in posture may be caused by the differences in light intensity or by a diurnal rhythm. to study this, rats were provided with eeg and emg electrodes for sleep classification and two housing conditions were created. one group of rats was maintained on a light/twilight schedule, while another group lived on a twilight/dark schedul ... | 1991 | 1946735 |
| interleukin 1 alters rat sleep: temporal and dose-related effects. | rats received various doses of interleukin 1 (il-1) (range, 0.5-25.0 ng) or pyrogen-free saline intracerebroventricularly during the rest (light) and the active (dark) cycles of the day, and sleep-wake activity and brain temperature were determined for 6 h. low doses of il-1 (0.5 ng at night, 2.5 ng during the day) increased both the duration of non-rapid-eye-movement sleep (nrems) and electroencephalogram (eeg) slow-wave activity during nrems episodes. increasing doses of il-1 had divergent eff ... | 1991 | 1992828 |
| sleep in diabetic rats: effects of interleukin 1. | previous observations indicate that both interleukin 1 beta (il-1 beta) and insulin are involved in sleep regulation. il-1 beta has been reported to stimulate insulin secretion, suggesting that some of the effects of il-1 beta are mediated by insulin. the purpose of the current experiments was to study the possible role of endogenous insulin in physiological sleep regulation and in the hypnogenic effects of exogenously administered il-1 beta. isotonic saline or il-1 beta (2.5 ng) was intracerebr ... | 1991 | 2035711 |
| effects of ethanol inhalation on eeg in rats. | effects of ethanol on duration of stages of sleep-wake cycle and eeg power spectra were measured during a 2-h exposure in a dynamic inhalational chamber in rats. rats were exposed to one of four graded concentrations (approx. 100, 400, 800 and 1600 ppm) of ethanol on different days. ethanol was found to increase the duration of waking (w) with a decrease in duration of rapid eye movement (rem) sleep at 100 and 400 ppm. no effect was observed at 800 and 1600 ppm on the stages of sleep-wake cycle ... | 1991 | 2057499 |
| sleep continuity and the rem-nonrem cycle in the rat under baseline conditions and after sleep deprivation. | wakefulness, nonrapid eye movement sleep (nonrems) and rems of rats were scored in 4-s epochs during the first 8 h of the 12-h light period of a baseline (bl) day and during recovery (rec) from 24-h sleep deprivation (sd). vigilance state continuity was investigated by analyzing the distribution of state episodes. after sd, state continuity was enhanced. the reduced occurrence of short wake episodes resulted in a consolidation of sleep states. the distribution of the rem-nonrem cycle length show ... | 1991 | 2062936 |
| sleep and waking have a major effect on the 24-hr rhythm of cortical temperature in the rat. | the relationship between the time course of cortical temperature (tcrt) and sleep-wake alternation was investigated by correlation analyses and a computer simulation. the data for these analyses were collected in 10 rats in a 4-day experiment (ld 12:12), during which vigilance states and tcrt were determined for consecutive 8-sec epochs. on day 1 baseline recordings were obtained; on day 2 the animals were sleep-deprived; and days 3 and 4 served as recovery days. the correlation analyses reveale ... | 1992 | 1286205 |
| theta waves and behavioral manifestations of alertness and dreaming activity in the rat. | electro-oscillographic recordings show that when rats wake up, behavioral manifestations such as head dorsal extension and snout and eye movements (which occur in this sequence), occasionally followed by brief ear and limb twitches, are preceded by and are simultaneous with theta waves (around 6.5 hz in frequency) in neocortical areas 3 and 17 and in the hippocampus. heart rate increases when the animal passes from synchronized sleep to relaxed wakefulness to exploratory behavior. during desynch ... | 1992 | 1342605 |
| visual evoked potentials during spontaneously occurring spike-wave discharges in rats. | flash evoked visual potentials (veps) were recorded in freely moving wag/rij rats. these rats show spontaneously occurring spike-wave discharges in the eeg, interpreted as absence-like seizures. veps recorded during the presence of spike-wave discharges were compared with those obtained during normal states of vigilance as quiet wakefulness, slow-wave sleep and rem sleep. almost similar veps were recorded during wakefulness and rem sleep, whereas during slow-wave sleep the second positive peak ( ... | 1992 | 1372232 |
| sleep homeostasis in suprachiasmatic nuclei-lesioned rats: effects of sleep deprivation and triazolam administration. | the electroencephalogram (eeg) and electromyogram of rats with lesions in the suprachiasmatic nuclei (scnx) were recorded during two series of 24-h baseline, 6-h sleep deprivation (sd), and 24-h recovery. at recovery onset, rats were injected i.p. with vehicle (veh) control solution or 0.4 mg/kg triazolam (trz) in a balanced crossover design. consecutive 10-s epochs were scored for vigilance states and eeg power spectra were computed. arousal states were uniformly distributed during 24-h baselin ... | 1992 | 1393593 |
| sleep deficits in rats after nmda receptor blockade. | n-methyl-d-aspartate (nmda) receptor blockade disrupts a variety of functions associated with neural plasticity, including acquisition of learned responses and long-term potentiation. deficits in memory are significantly correlated with deficits in measures of paradoxical sleep in several amnesic populations. the present experiment therefore assessed whether npc 12626, a competitive nmda receptor antagonist, also disrupts sleep. npc 12626 (1, 10, 50, and 100 mg/kg) or saline was administered to ... | 1992 | 1409928 |
| tumor necrosis factor-beta induces sleep, fever, and anorexia. | the enhanced sleep, fever, and anorexia experienced during general infections are attributed to the increased production of cytokines. cytokines such as interleukin-1 and tumor necrosis factor-alpha (tnf-alpha) have characteristic somnogenic, pyrogenic, and anorectic effects. tnf-beta is closely related to tnf-alpha, and they share common receptors. the effects of tnf-beta on sleep-wake activity, brain temperature (tbr), and food intake were, however, heretofore unknown. we injected 0.5-200 ng t ... | 1992 | 1415661 |
| growth hormone-releasing hormone antibodies suppress sleep and prevent enhancement of sleep after sleep deprivation. | previous reports suggest that the hypothalamic growth hormone-releasing hormone (ghrh) promotes sleep, especially non-rapid-eye-movement sleep (nrems). to evaluate the role of endogenous ghrh in sleep regulation, the effects of antibodies to rat ghrh (ghrh-ab) were studied on normal sleep, brain temperature (tbr), and gh secretion in experiment i and on enhanced sleep after sleep deprivation in experiment ii. in experiment i, affinity-purified ghrh-ab (50 and 200 micrograms) raised in goats and ... | 1992 | 1443226 |
| an animal model for delirium. | this study describes an animal model for delirium comparing rats treated with either saline or atropine. the model was defined by recordings of cortical eegs, maze performance, and behavioral observations. eeg slowing and increased amplitude, difficulty with attention and memory, sleep-wake cycle reversal, and changes in behavior (lack of focused direction, irritability, fluctuating levels of activity, excessive random sniffing) appeared consistent with signs and symptoms seen in human delirium. ... | 1992 | 1461966 |
| age-variant and age-invariant rhythmicities in the cortical and hippocampal electrical activities of neonatal rats. | the neocortical and hippocampal electrical activities were studied in 8, 15, 22, and 29-day-old rats. segments of eeg recorded for 4 hours were analyzed by means of fast fourier transformation. the sleep-wake activity stages were determined. the developments in the neocortical and hippocampal eeg activities were characterized by the gradual appearance of adult-like eeg waves and a shift towards higher frequencies in the theta wave range of the hippocampal electrical activity. the power value in ... | 1992 | 1478115 |
| antiserum to prolactin decreases rapid eye movement sleep (rem sleep) in the male rat. | previous reports suggest that blood-born prolactin (prl) may selectively promote rapid eye movement sleep (rems). to study the possible involvement of endogenous prl in sleep regulation, rats were systemically injected with either antiserum to prl or normal rabbit serum, and the sleep-wake activity was determined during the subsequent 12-h light cycle. the administration of normal rabbit serum in physiological saline did not alter sleep-wake activity compared to control recordings, whereas the p ... | 1992 | 1484861 |
| neuronal firing in the nucleus accumbens is associated with the level of cortical arousal. | because of evidence that the nucleus accumbens mediates the activating effects of many drugs, this study examined the hypothesis that the firing rates of individual nucleus accumbens neurons are positively correlated with spontaneous changes in behavioral arousal that occur during the sleep-wake cycle. the present report examined the firing patterns of 80 neurons in the nucleus accumbens of unanesthetized, unrestrained rats during various electrographically determined levels of arousal. synaptic ... | 1992 | 1488114 |
| effects of an eight-hour advance of the light-dark cycle on sleep-wake rhythm in the rat. | we observed effects of an 8-h advance of the light-dark (ld) cycle on the sleep-wake rhythm in the rat. on the day phase-advanced, rapid eye movement (rem) sleep increased with its enhanced diurnal amplitude. non-rem (nrem) sleep gradually increased in parallel with the decrease of its diurnal amplitude. although the acrophase of nrem sleep gradually advanced after the phase advance, that of rem sleep did not significantly change. we confirmed that diurnal rhythm of rem sleep was hardly shifted ... | 1992 | 1584456 |
| studies on sleep/wake effects of serotonin reuptake inhibitors and receptor subtype involvement. | studies with the serotonin uptake inhibitors zimeldine and alaproclate show biphasic effects on the sleep/wake axis in rats and cats. zimeldine induced an initial waking response succeeded by a small sws-2 increase in rats. the waking increase was not blocked by the 5-ht2 antagonist ritanserin nor by the putative 5-ht1a antagonist (-)-alprenolol. in cats, zimeldine induced initial behavioural changes which were succeeded by a large sws-2 increase. alaproclate gave similar initial responses as zi ... | 1992 | 10607045 |
| dual projections of single cholinergic and aminergic brainstem neurons to the thalamus and basal forebrain in the rat. | compelling evidence indicates that cholinergic basal forebrain neurons are strongly activated during waking, and concurrently thalamic spindle activity is suppressed and thalamocortical sensory transmission is facilitated. both thalamus and basal forebrain are known to receive projections from brainstem cholinergic and aminergic neuronal pools that are involved in wake/sleep regulation. the present study addressed the question of whether single cholinergic and aminergic neurons contributed to bo ... | 1993 | 7681346 |
| the dopamine d1 receptor agonists, a68930 and skf 38393, induce arousal and suppress rem sleep in the rat. | the effects of the dopamine d1 receptor full agonist, a68930, on sleep-wake patterns and grooming behaviour were studied in the rat. the partial dopamine d1 receptor agonist, skf 38393, was used for comparison. a68930 (0.003-0.3 mg/kg s.c.) increased waking time, reduced the amount of rapid eye movement (rem) sleep and enhanced spontaneous grooming dose dependently. the ed50 were 0.06, 0.02 and 0.05 mg/kg, respectively. the d1 antagonist, sch 23390 (0.003 mg/kg s.c.), blocked the effects of a689 ... | 1993 | 8100197 |
| differential effects of dopamine d-1 and d-2 receptor antagonist antipsychotics on sleep-wake patterns in the rat. | a series of antipsychotics having different selectivity for dopamine (da) d-1 and d-2 receptors were studied for their effects on sleep stages in the rat. electroencephalographic activity was recorded and classified according to the stages of wakefulness, rapid eye movement (rem) sleep and non-rem sleep. total sleep duration, non-rem and rem latencies, number and duration of rem episodes were calculated. the da d-1 antagonists, sch 23390 (0.001-0.1 mg/kg s.c.), sch 39166 (0.01-0.3 mg/kg s.c.) an ... | 1993 | 8102647 |
| injection of tetanus toxin into the neocortex elicits persistent epileptiform activity but only transient impairment of gaba release. | focal injection of a minute quantity of tetanus toxin into the rat neocortex induces chronic epileptogenesis. within a day, spontaneous and stimulus-evoked paroxysmal discharges appear in widespread regions of both hemispheres and this lasts for at least nine months. tetanus toxin blocks transmitter release, apparently by catalysing the breakdown of synaptobrevin, a synaptic protein. it specifically binds to neuronal membranes but its potent epileptogenic properties have been ascribed to a highe ... | 1993 | 8115035 |
| anatomical distribution of prolactin-like immunoreactivity in the rat brain. | the present study examines prolactin prl-like immunoreactivity (prl-lir) in the rat central nervous system and describes the distribution of labeled perikarya and fibers using a specific antiserum to ovine prl. this antiserum does not cross-react with molecules of the pro-opiomelanocortin (pomc) family and recognizes rat prl. prl-lir cell bodies are found exclusively in the lateral hypothalamic area surrounding the fornix, especially dorsolateral to it. no labeled cells are detectable in any oth ... | 1993 | 8127395 |
| intravenous administration of inorganic selenium compounds, inhibitors of prostaglandin d synthase, inhibits sleep in freely moving rats. | prostaglandin (pg) d2 has been postulated to be an endogenous sleep-promoting factor. biosynthesis of pgd2 is catalyzed by pgd synthase (prostaglandin-h2 d-isomerase, ec 5.3.99.2), the activity of which is inhibited by inorganic selenium compounds such as secl4 and na2seo3. we recently examined the effect of intracerebroventricular administration of these selenium compounds on sleep in rats, and demonstrated time- and dose-dependent sleep inhibition. to establish whether this effect of selenium ... | 1993 | 8221095 |
| spontaneous activity in the thalamic reticular nucleus during the sleep/wake cycle of the freely-moving rat. | neurons of the somatosensory thalamic reticular nucleus (trn) were studied by extracellular recordings through the sleep/wake cycle in the unanesthetized, freely-moving rat. all electrophysiologically-identified trn neurons expressed rhythmic patterns of discharge that altered with shifts in sleep/wake state. during slow wave (sw) sleep, neurons displayed spike-burst discharges in long trains followed by pauses. high-frequency oscillations in auto-correlograms in the spindle-frequency range (app ... | 1993 | 8221106 |
| cholinergic receptor subtypes and rem sleep in animals and normal controls. | as reviewed here and elsewhere in this symposium, acetylcholine, in conjunction with other neurotransmitter systems, plays a very important role in the regulation of circadian and sleep-wake states. to briefly recapitulate, several current basic concepts about the regulation of sleep-wake states include: (a) rem sleep, or at least its phasic events (eye movements and pgo spikes), are promoted by cholinergic neurons originating within the peribrachial regions [ldt/ppt] (mitani et al., 1988; shiro ... | 1993 | 8248526 |
| successful use of s20098 and melatonin in an animal model of delayed sleep-phase syndrome (dsps). | in human delayed sleep-phase syndrome (dsps), sleep onset and wake times occur far later than normal. in the population, dsps may be an important contributor to complaints of sleep onset insomnia. we previously reported an animal model of dsps in laboratory rats in which the onset of nocturnal activity is delayed by several hours [negative phase angle difference (pad)]. the effect of melatonin 1 mg/kg sc and s20098 (servier) 1 and 3 mg/kg on the negative pad was investigated over 22 days of inje ... | 1993 | 8255922 |
| the influence of the muscarinic receptor subtypes on the sleep-wake cycle. | the specific role played by different muscarinic receptor subtypes in sleep regulation is investigated and discussed. on the basis of the results obtained with intracerebroventricular injections of selective muscarinic antagonists into freely moving rats, it is suggested that each muscarinic receptor subtype induces different and specific changes in sleep phases and cortical desynchronization processes. | 1993 | 8259978 |
| melatonin, the pineal gland, and circadian rhythms. | amniote circadian organization derives from the interactions of circadian oscillators and photoreceptors located in the hypothalamic suprachiasmatic nuclei (scn), the pineal gland, and the eyes. in mammals, circadian organization is dominated by the scn, which serve as "master pacemakers" in the control of a wide array of behavioral and physiological rhythms (including locomotion, sleep-wake, thermoregulation, cardiovascular function, and many endocrine processes). among the rhythms under scn co ... | 1993 | 8274765 |
| spinal cord blood flow changes during the sleep-wake cycle in rat. | regional spinal cord blood flow was measured in rats during the sleep-wake cycle with the use of radioactive microspheres. spinal cord blood flow decreases from wakefulness to quiet (synchronized) sleep while increasing in active (desynchronized) sleep. blood-flow changes depend on changes in vascular resistance whose mechanisms have yet to be elucidated. blood-gas tension or mean arterial pressure, however, do not play a relevant causal role. | 1993 | 8309626 |
| day-night variations of adenosine and its metabolizing enzymes in the brain cortex of the rat--possible physiological significance for the energetic homeostasis and the sleep-wake cycle. | the role of adenosine as a metabolic regulator of physiological processes in the brain was studied by measuring its concentrations and the activity of adenosine-metabolizing enzymes: 5'-nucleotidase, s-adenosylhomocysteine hydrolase, adenosine deaminase and adenosine kinase in the cerebral cortex of the rat. other purine compounds, such as, inosine, hypoxanthine and adenine nucleotides were also studied. the purines' pattern was bimodal with high levels of adenosine, inosine and hypoxanthine dur ... | 1993 | 8330191 |
| methyl parathion induced alterations in gabaergic system during critical stage of central nervous system development in albino rat pups. | sublethal doses of methyl parathion (o, o-dimethyl-o-nitrophenyl thiophosphate) injected intraperitoneally to 7th day old developing albino rat pups induced alterations in the inhibitory gabaergic system of cns. a substantial simulation of the inhibitory system was noticed. a profound increase was found in the level of the inhibitory transmitter, gaba on methyl parathion injection. an increase in the activity levels of the enzymes glutamic acid decarboxylase and 4-aminobutyrate-2-oxoglutarate-am ... | 1993 | 8359836 |
| reliability and validity of computer scoring of behavioral sleep-wake states in rats and rabbits. | previous studies in human infants, rabbits, and rats have shown that states of sleep and wakefulness can be reliably identified from motility signals produced by respiration and body movement. thoman has described a computer-scoring algorithm for automated scoring of behavioral states from motility signals in human infants. in the present studies, we report the use of the computer scoring program with motility signals obtained from electronic activity monitors. in the newborn rabbit, computer cl ... | 1993 | 8372120 |
| differences in the retinohypothalamic tract in albino lewis versus brown norway rat strains. | differences in sleep-wake patterns in response to light-dark stimulation have been observed between albino lewis and pigmented brown norway strains of rats, which may be associated with albinism. since several anatomical differences have been demonstrated in the visual pathways of albino and pigmented mammals, the present study was undertaken to determine whether additional differences in visual pathways of these rat strains exist that might account for their behavioral differences. using antero ... | 1993 | 8390623 |
| effect of prolactin on the sleep-wake cycle in the rat. | the purpose of this study was to examine the effects of prolactin on the sleep-wake cycle. ovine prolactin was injected subcutaneous at a dose of 10 micrograms/animal or intra-cerebro-ventricularly at doses of 100, 10 and 1 ng/animal. the subcutaneous injections were given during either the diurnal or nocturnal period. results indicate that oprl decreases paradoxical sleep duration when injected during the dark period and increases it when injected during the light period. the i.c.v. injections ... | 1993 | 8414171 |
| hippocampal interneuron activity in unanesthetized rats: relationship to the sleep-wake cycle. | evoked population spikes and interneuronal discharges were recorded throughout the sleep-wake cycle in hippocampal regions ca1 and dentate gyrus (dg) of ten chronically implanted rats. during quiet wakefulness (qw) and slow-wave-sleep (sws) (non-theta rhythm states), the primary shock of paired stimuli evoked in ca1 both high amplitude population spikes and multiple interneuron discharges when compared to active wakefulness (aw) and rapid-eye-movement (rem) sleep (theta rhythm states). a second ... | 1993 | 8414179 |
| effect of light intensity on diurnal sleep-wake distribution in young and old rats. | during the aging process, the amplitude of the circadian rhythms of many physiological variables is reduced. it has been hypothesized that increasing light intensity during the light phase of the light-dark cycle might result in a reduction of age-related changes in the circadian rhythms. indeed, in the present sleep-wake study in young and old rats it was found that (a) various parameters, such as the light-dark differences and total amounts of each behavioral state responded positively to chan ... | 1993 | 8420626 |
| electroencephalographic changes in experimental autoimmune myasthenia gravis. | a number of reports have suggested that central disturbances of cholinergic function may occur in patients with myasthenia gravis. the present study was designed in order to examine cortical electroencephalographic (eeg) activity in lewis rats with experimental autoimmune myasthenia gravis (eamg). experiments were performed on conscious rats with clinical eamg and demonstrable antibodies against the acetylcholine receptor. the animals showed no gross changes in cortical eeg discharge in terms of ... | 1993 | 8445401 |
| transient hyperemia succeeds oligemia in the wake of cortical spreading depression. | regional cerebral blood flow (rcbf) was examined following single episodes of cortical spreading depression (csd) in rat brain after an intravenous bolus injection of [14c]iodoantipyrine. cortical rcbf decreased to approximately 75% of control values during the first 60 min after csd. this change was succeeded at 90-105 min by a small, transient flow increase. rcbf returned to normal at 120 min after csd, and remained normal for the following 2 h. the same sequence of rcbf changes has been recor ... | 1993 | 8448676 |
| the relative effects of selective m1 muscarinic antagonists on rapid eye movement sleep. | three muscarinic antagonists, scopolamine, trihexyphenidyl and biperiden were systemically administered (0, 0.5, 1, 2 and 4 mg/kg) in rats. scopolamine increased wakefulness and deceased sleep, both slow wave and rem. trihexyphenidyl increased wakefulness and decreased rem sleep while biperiden decreased rem sleep selectively. the rank order rem-suppressing effect was roughly scopolamine and trihexyphenidyl having a greater suppressing effect than biperiden. these results suggest that the regula ... | 1993 | 8495352 |
| effect of ephedrine on muscle weakness in a model of myasthenia gravis in rats. | in addition to therapy with anticholinesterases, ephedrine is sometimes used to improve muscle strength in myasthenia gravis, with variable results. the efficacy of ephedrine was tested in rats with a alpha-bungarotoxin-induced model of myasthenia gravis. the rats showed a drooping lower lip and impaired capability of drinking. injections of neostigmine caused an improvement of the position of the lip. ephedrine caused some improvement. however, ephedrine had no effect, either on the lower lip o ... | 1993 | 8497338 |
| daily variations in concentration of vasoactive intestinal peptide immunoreactivity in hypothalamic nuclei of rats rendered diurnal by restricted-schedule feeding. | we previously described that in the suprachiasmatic (scn), peri-(pevn) and paraventricular (pavn) nuclei of normal rats, vasoactive intestinal peptide (vip)-like immunoreactivity (vip-li) accumulates during the night period and decreases during the day. in order to determine whether these variations are linked to the light-dark cycle or are a consequence of sleep-wake rhythm expression, we dissociated these two parameters by restricting feeding to diurnal hours. in these conditions which inverse ... | 1993 | 8515863 |
| sleep-wake disturbances in an animal model of chronic cholinergic insufficiency. | rats reared on a diet in which choline is replaced with n-aminodeanol (nade), undergo > 50% replacement of brain acetylcholine with acetylated nade, a false cholinergic transmitter. we examined amounts of sleep and wakefulness in 7 littermate pairs of rats fed either nade-substituted, or a choline control diet for > 100 days after weaning. during the lights-on portion of the 12/12 h light/dark cycle, nade rats spent more time awake, and less time in both non-rem and rem sleep compared to litterm ... | 1993 | 7904530 |
| epilepsy and sleep. | this review discusses several aspects of epilepsy and sleep. the level of wakefulness is controlled by transmitters such as acetylcholine, norepinephrine, serotonin, and histamine. these neurotransmitters are involved in modulatory neurotransmission of the ascending brain stem systems, which play an important role in controlling the sleep-wake cycle. experimental evidence suggests that rapid eye movement sleep atonia is induced by increased endogenous acetylcholine release. regarding sleep facto ... | 1994 | 7912613 |
| time-related changes in the sleep-wake cycle of rats infected with trypanosoma brucei brucei. | patients with human african trypanosomiasis, sleeping sickness, show a major disturbance in the circadian distribution of sleeping and waking, with sleep and wake episodes equally distributed throughout the nycthemeron. in order to develop an animal model, polysomnography was taken continuously in 8 male ofa rats in a 12:12 h light-dark cycle, during 1 baseline week and for 2 weeks after infection with trypanosoma brucei brucei. considerable sleep fragmentation was observed in the infected rats, ... | 1994 | 7913215 |
| different programs of gene expression are associated with different phases of the 24h and sleep-wake cycles. | the fos and jun proteins are encoded by proto-oncogenes acting as immediate early genes in that they are rapidly induced by different kinds of stimuli in the nervous system. these two proteins bind to dna regulating gene transcription, and thus determining the specificity of the neuronal response to the applied stimulation. we investigated whether the expression of these genes undergoes a variation during 24h in the absence of exogenous stimulation. male wistar adult (200 gr. body weight) rats, ... | 1994 | 7924645 |