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Results 651 - 700 of 1320
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Berger N - - 2000
Genetic predisposition and environmental factors such as perinatal complications are believed to contribute to the etiology of schizophrenia, a disorder involving enhanced CNS dopaminergic activity. This study used a rat model to test whether genetic factors and a minor birth complication, i.e. Caesarean section (C-section) birth, interact in producing longterm ...
Rousseau J B - - 2000
Video recordings of 11 rats were digitized at five frames per second, and parameters describing the shape and the position of the rat were calculated. The behavior displayed by the rats was observed by an experienced observer. Separate neural networks were trained and validated, using the data for each individual ...
Ellenbroek B A - - 2000
RATIONALE: There is ample evidence that rats show large individual differences in their response to dopaminergic drugs, such as apomorphine. OBJECTIVE: The aim of the present study was to investigate the role of genetic and (early) environmental factors in determining the adult susceptibility to apomorphine. Four experiments were performed: In ...
López-Rubalcava C - - 2000
Wistar-Kyoto (WKY) rats provide a model of stress-induced depressive behavior, because they show enhanced vulnerability to the effects of stressors. The present study examined differences in the behavioral response to different types of antidepressant drugs between WKY and Sprague-Dawley (SD) rats in the forced swimming test (FST). WKY rats displayed ...
Voigt J P - - 2000
Transgenic techniques provide a tool to generate animals that differ from the wild-type by one or more genes, either by introducing foreign genes (transgenic animals) or by specific mutations of genes (knock-out animals). Most transgenic and knock-out animals are mice and not rats. The frequent use of rat models in ...
Paulus M P - - 2000
Rats housed in social isolation postweaning (isolates) show profound behavioral and neurobiological differences when compared to socially housed rats (socials). Fischer rats (F344) relative to Lewis rats are hyperresponsive and significantly more susceptible to stressful stimuli. This investigation tested the hypothesis that the behavioral effects of postweaning isolation are more ...
Salum C - - 2000
This work describes a neural network model of the rat exploratory behavior in the elevated plus-maze, a test used to study anxiety. It involves three parameters: drive to explore; drive to avoid aversive stimuli; and spontaneous locomotor activity. Each network unit corresponds to a specific location in the maze and ...
Stefanova N - - 2000
The present review summarizes the up-to-date knowledge on the sexual dimorphism of the CNS with special regard to the sexual differentiation of the bed nucleus of the stria terminalis (BST) and the amygdala in rat. The authors provide new evidence for the sexual dimorphism and differentiation of GABAergic, leucine-enkephalin-containing and ...
Wesierska M - - 2000
We observed the spontaneous behavior of a laboratory marsupial--the gray short-tailed opossum (Monodelphis domestica)--in the elevated plus-maze (EPM) during six consecutive sessions and compared it with the behavior of Long-Evans rats. During the first exposure to the maze both species spent most of the time in the enclosed arms but ...
Monzón M E - - 1999
Some behavioral response of rats to spatial novelty after i.c.v. administration of melanin-concentrating hormone (MCH) were evaluated. To this purpose, an open-field test was used, as well as an elevated plus-maze to study the possible anxiolytic effect of this peptide. In the open field, the frequency of exploratory components (locomotion ...
Rodríguez-Manzo G - - 1999
The purpose of the present study was to analyze the anxiety-like effect induced by ejaculation in male rats subjected to different sexual behavior conditions. The animal model of anxiety used was the conditioned defensive burying test. Results showed that experimental anxiety was reduced after one or six consecutive ejaculations. Six ...
Yoon Y W YW Marine Biomedical Institute, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1069, - - 1999
This study compared and contrasted the manifestation of neuropathic pain behaviors in several strains of rats. These included ACI, Brown-Norway, Fischer 344, Lewis, Long-Evans, Sprague-Dawley, and Wistar-Furth, all obtained from Harlan Sprague-Dawley Inc. Comparison was also made between two substrains of Sprague-Dawley rats: one from Harlan and the other from ...
Djurić V J - - 1999
Both major depression and depressive symptoms are associated with a high rate of nicotine dependence, and a history of major depression has an adverse impact on smoking cessation. The main objective of this study was to investigate whether continuous ingestion of nicotine affects indices of depressive behavior in the rat. ...
Rogóz Z - - 1999
Pharmacological effects of acute treatment with reboxetine (REB), a clinically active antidepressant (a noradrenaline reuptake inhibitor without any affinity for neurotransmitter receptors), were studied in mice and rats. REB inhibited the reserpine- or apomorphine-induced hypothermia in mice. It reduced the immobility time in Porsolt's test in mice and rats, but ...
Tsibulsky V L - - 1999
The intervals between self-injections of cocaine by rats are defined by an equation that contains only three parameters: the dose of cocaine administered, the elimination half-life of cocaine, and an amount of cocaine in the body, which we have termed the cocaine satiety threshold. This latter parameter is defined as ...
Escorihuela R M - - 1999
In the present study, male inbred animals (from the 10th generation of an inbreeding program that has been carried out in parallel to that of the outbred Roman high- and low-avoidance rat lines), were compared for emotionality in different testing situations, exploratory behavior in the holeboard and two-way, active-avoidance acquisition. ...
Primeaux S D - - 1999
The aim of the present studies was to determine the extent to which changes in defensive behaviors could account for some of the behavioral effects of bilateral olfactory bulbectomy (OBX) in rats. Four tests of aversively-motivated behavior were conducted in bulbectomized and sham-operated rats: activity in a dimly lit or ...
Rogóz Z - - 1999
Pharmacological effects of acute treatment with milnacipran (MIL), a clinically active antidepressant (a noradrenaline [NA] and 5-hydroxytryptamine [5-HT] reuptake inhibitor without any affinity for neurotransmitter receptors) were studied in mice and rats. MIL inhibited the reserpine- or apomorphine-induced hypothermia in mice and enhanced the L-5-hydroxytryptophan-induced head twitches in rats. It ...
Harkany T - - 1999
A putative tetrapeptide beta-amyloid (Abeta) antagonist (propionyl-Ile-Ile-Gly-Leu [Pr-IIGL]) based on the [31-34] sequence of Abeta was previously shown to rescue astrocytes from Abeta-induced membrane depolarization and subsequent long-term elevations of the intracellular Ca2+ concentration in vitro. Here we provide in vivo evidence that the Pr-IIGL tetrapeptide effectively attenuates the excitotoxic ...
Voigt J P - - 1999
The transgenic rat TGR(mREN2)27 was generated to study mechanisms involved in the hypertensive process. A characteristic of this rat is a high expression of the murine renin-2 gene in several peripheral tissues and in the brain. The high expression of the transgene is associated with increased local formation of angiotensin ...
Fernández-Guasti A - - 1999
The effect of chronic desipramine (DMI, 2.5 mg/kg x 21-26 days) treatment in female rats in two anxiety paradigms was assessed: the burying behavior (BB) and the elevated plus-maze (EPM) tests. In the BB test DMI produced a significant decrease in burying in ovariectomized rats, an effect considered as anxiolytic-like. ...
Jolly D C - - 1999
BACKGROUND: The functioning of the brain serotonin system has been implicated in the action of antidepressant drugs. The behavior of rats performing the Differential Reinforcement of Low Rate-72 sec (DRL 72s) has been used as a screen for drugs with antidepressant activity. Many antidepressant drugs alter serotonergic function. Hence, experiments ...
Rex A - - 1999
Inbred Fisher 344 and outbred Harlan-Wistar rats were compared in the elevated plus maze, the black-and-white box, the social interaction test, and a modified open-field test, to assess the contribution of genetic factors to aversion-motivated behavior. All animals used were born and raised under identical conditions. Compared to the Wistar ...
Sato J - - 1999
To examine the effects of meteorological change on the pain-related behaviors of neuropathic rats, animals with a chronic constriction injury (CCI) to the sciatic nerve were exposed to low barometric pressure (LP), 20 mmHg below the natural atmospheric pressure in a climate-controlled room. CCI caused a decreased hindpaw withdrawal threshold ...
Andres K H - - 1999
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 ...
Ohta R - - 1999
Having successfully bred for high- and low-avoidance rats (HAA and LAA, respectively) on a shuttlebox task, we performed three experiments designed to identify factors which might be related to the phenotypic differences seen in avoidance behavior. In experiment 1, shuttlebox behavior was measured to determine whether the phenotypic difference was ...
Vives M A - - 1999
The effects of new synthetic lysine-derived anionic surfactants on human and rat erythrocytes were studied. The surfactants were salts of Nalpha,Nepsilon-dioctanoyl lysine with different counterions: lysine (77KK), tris (trishydroxymethyl amminomethane) (77KT), sodium (77KS), and lithium (77KL). 77KK and 77KT showed a biphasic hemolytic behavior in the erythrocytes. The surfactants 77KS ...
Lenczowski M J - - 1999
Interleukin (IL)-6 has been proposed to mediate several sickness responses, including brain-mediated neuroendocrine, temperature, and behavioral changes. However, the exact mechanisms and sites of action of IL-6 are still poorly understood. In the present study, we describe the effects of central administration of species-homologous recombinant rat IL-6 (rrIL-6) on the ...
Stock H - - 1999
Nonprecipitated benzodiazepine (BZ) withdrawal has been reported to increase anxiety levels in rats. The present experiment determined if gender or hormonal status would modulate putative changes in anxiety-related behaviors during precipitated BZ withdrawal in rats. Intact and gonadectomized male and female rats were treated for 4 weeks with empty or ...
Petrov E S - - 1999
Newborn rats showed mouthing, licking, and oral grasping when presented with a surrogate nipple. These responses changed after the pup expressed an oral grasp response and experienced milk at the nipple. Newborn pups that ingested milk from the surrogate nipple showed brief oral grasp responses and, when tested 1 hr ...
Deak T - - 1999
The nonpeptide CRH antagonist antalarmin has been shown to block both behavioral and endocrine responses to CRH. However, it's potential activity in blunting behavioral and endocrine sequelae of stressor exposure has not been assessed. Because antagonism of central CRH by alpha-helical CRH attenuates conditioned fear responses, we sought to test ...
Kemerov S - - 1999
The present study aimed at comparative assessment of the changes in behavioral activity of rats after exposing them to low intensity electromagnetic fields (EMFs) in the meter, decimeter and centimeter ranges. The experiments were carried out on 24 Wistar rats divided into 4 groups (1 control and 3 experimental), treated ...
Patterson-Kane E G - - 1999
A study compared the behavior of rats kept under standard conditions with the behavior of those from enriched, semi-enriched, and single-housed conditions to determine whether standard conditions have detrimental effects on nonhuman animal welfare. The subjects were 35 female Hooded Norway rats. Using an emergence box, open field, and Hebb-Williams ...
Davis J D - - 1999
This review focuses on new developments in the understanding of how oropharyngeal and postingestional stimulation control the ingestive behavior of the rat ingesting liquids. With the development of the computer-controlled lickometer it is now possible to measure and analyze in fine detail the impact these two variables have on the ...
Apfelbach R - - 1998
Rats were trained using an olfactometer to detect low concentrations of ethyl acetate (EA) or dimethyl disulphide vapor (DMDS). Concanavalin A (ConA) applied to the olfactory mucosa had no effect on ability of rats to detect low concentrations of EA but produced a marked deficit in detection in DMDS. DMDS ...
Matuszczyk J V - - 1998
Treatment with serotonin reuptake inhibitors (SRIs) has been shown to cause reduced libido and anorgasmia in women. A large body of evidence suggests that serotonin may influence sexual behavior in estradiol + progesterone primed, gonadectomized female rats; however, the influence of selective SRIs on the estrous behavior of intact female ...
Swain M G - - 1998
"Sickness behaviors" such as lethargy, fatigue, and malaise occur commonly in patients with cholestatic liver diseases and contribute significantly to the morbidity associated with these diseases. However, the cause of these symptoms is unknown. Interleukin-1beta (IL-1beta) released within the brain has been implicated in the genesis of a number of ...
Paulus M P - - 1998
Histocompatible Fischer 344 and Lewis rats have been shown to differ on a wide variety of behavioral, chemical, and molecular measures. This investigation aimed to clarify strain differences in unconditioned motor behavior with respect to the amount and patterns of movements. Twenty female Fischer 344, Lewis, and Sprague-Dawley were tested ...
Rosengarten H - - 1998
BACKGROUND: We have demonstrated that rats injected with D1 agonists SKF 38393 or A68930 demonstrate repetitive jaw movements (RJM). These agonist-induced movements in rats are similar in their appearance to those induced in rats by long-term treatment with antipsychotic drugs. Over recent years D-1 receptors were discovered which showed linkage ...
Kawaguchi A T - - 1998
BACKGROUND: Integrated neurological function, behavior, and somatic recovery were studied in 35 rats undergoing 5 to 80 minutes of hypothermic circulatory arrest (HCA). METHODS AND RESULTS: A closed extracorporeal circulation system (ECC) consisting of a miniature oxygenator and heat exchanger, primed with 6 mL of asanguinous solution, was connected to ...
Fink H H Institute of Pharmacology and Toxicology, Medical Faculty, Charité, Humboldt University at Berlin, - - 1998
Cholecystokinin (CCK) is one of the first discovered gastrointestinal hormones and one of the most abundant neuropeptides in the brain. Two types of CCK receptors have been identified: (1) CCK-A receptors are mainly located in the periphery, but are also found in some areas of the CNS; and (2) CCK-B ...
Ishmael J E - - 1998
Dextromethorphan and dextrorphan elicited a stereotyped behavioral syndrome in rats indistinguishable from that produced by PCP and other non-competitive NMDA antagonists. The rank order of potency for the induction of stereotyped behavior in male Sprague-Dawley rats was: MK-801>PCP>(+/-)cyclazocine>dextrorphan>(+/-)ketamine>dextromethorphan. These behavioral potencies were significantly correlated (0.91; P<0.05) with their respective affinities ...
Hawkins R L - - 1998
Rats were trained to maintain a high rate of bar pressing to receive 50-mg pellets of a complete diet when given a lysine-deficient (Lys-def) diet ad libitum. This bar-pressing behavior was significantly inhibited when rats were also allowed ad libitum access to 0.4 M Lys to drink. A brain activin ...
Cohen H - - 1998
BACKGROUND: Cholecystokinin (CCK) and its analogs generates anxiety in humans and measurable anxiety-like behaviors in rats. CCK receptor blockers have had mixed results as a treatment approach for anxiety disorders. Since CCK is a peptide, we explored another strategy to reduce CCK levels in brain by antisense oligodeoxynucleotide inhibition of ...
Schmitt U - - 1998
1. A test battery consisting of a standard open field, an enriched open field and an elevated plus maze was used to study behavior in rats. 2. Male rats of the strains PVG/OlaHsd (PVG) and Sprague-Dawley-Hsd (SPRD) (150-200 g body wt) were used to assess interstrain differences as well as ...
Lambadjieva N D - - 1998
The complicated reflex complexes on the basis of orientation exploratory-behavior, emotional state and pain reaction play an important role in the analisator activity of the brain cortex. The rate of inhibition of orientation-exploratory reactions shows the intensity of the inner inhibition. In a complex with other indicators it can characterize ...
Wagner C K - - 1998
In rats, fetal testosterone directs sexual differentiation of the brain. However, fetuses are also exposed to maternal progesterone. Here we report that progestin receptor immunoreactivity in the medial preoptic nucleus (MPN) of fetal and neonatal rats is high in males but virtually absent in females. The MPN is one of ...
Paulus M P - - 1998
OBJECTIVE: Dopaminergic and serotonergic modulation potently influences the sequential organization of rat movements in a simple unconditioned motor paradigm. Rats reared in social isolation post-weaning differ profoundly from their socially reared litter mates on behavioral, neurochemical, and neuroanatomical measures. This investigation examined (1) whether social isolation significantly affects the sequential ...
Balcells-Olivero M - - 1998
Several compounds were tested on the differential-reinforcement-of-low-rate 72-sec (DRL 72-sec) schedule, a behavioral screen to determine putative antidepressants; these compounds were evaluated in two outbred stocks of rats, Harlan and Holtzman Sprague-Dawley rats. A dose-response determination for the tricyclic antidepressants, imipramine and desipramine, the selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitor, ...
Privou C - - 1998
This study examined the effects of the H1-antagonist chlorpheniramine and the H2-antagonist ranitidine on reinforcement and anxiety-parameters following unilateral injection into the vicinity of the nucleus basalis magnocellularis (NBM). In Experiment 1, rats with chronically implanted cannulae were injected with chlorpheniramine or ranitidine (each at doses of 0.1, 1, 10 ...
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