The Experts below are selected from a list of 195 Experts worldwide ranked by ideXlab platform
Neal R. Swerdlow - One of the best experts on this subject based on the ideXlab platform.
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Rat Strain Differences in startle gating-disruptive effects of apomorphine occur with both acoustic and visual prepulses.
Pharmacology biochemistry and behavior, 2007Co-Authors: Martin Weber, Neal R. SwerdlowAbstract:Prepulse inhibition of startle (PPI) is an operational measure of sensorimotor gating that is impaired in schizophrenia and is disrupted in rats by dopamine (DA) agonists like apomorphine (APO). Using acoustic prepulses and acoustic startle pulses, previous studies have demonstrated heritable Strain Differences between Sprague Dawley (SD) and Long Evans (LE) rats in the sensitivity to the PPI-disruptive effects of APO. As PPI deficits in schizophrenia are evident with both uni- and cross-modal stimuli, we tested whether Strain Differences in the gating-disruptive effects of APO occur with a cross-modal visual and acoustic stimulus combination. APO caused a dose-dependent disruption of both acoustic and visual PPI in SD rats. Compared to LE rats, SD rats were more sensitive to the PPI-disruptive effects of APO with both acoustic and visual PPI. These findings suggest that SD vs. LE Strain Differences in PPI APO sensitivity are mediated outside of the auditory system, within higher circuitry that regulates or processes multi-modal information. The present findings provide further validation for this heritable model of impaired sensorimotor gating in schizophrenia, which can be detected across multiple sensory modalities.
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Neurochemical analysis of rat Strain Differences in the startle gating-disruptive effects of dopamine agonists.
Pharmacology biochemistry and behavior, 2004Co-Authors: Neal R. Swerdlow, Ronald Kuczenski, Jana Goins, Sarah Crain, Lillian T., Michele J. Bongiovanni, Jody M. ShoemakerAbstract:The disruption of prepulse inhibition (PPI) in rats by dopamine (DA) agonists is used to study the neural basis of Strain Differences in dopaminergic function. We reported that, compared to Long-Evans (LEH) rats, Sprague-Dawley (SDH) rats are more sensitive to the PPI-disruptive effects of the direct D1/D2 agonist apomorphine (APO) and the indirect DA agonist d-amphetamine (AMPH). This Strain difference is heritable, with PPI drug sensitivity following a generational pattern (SDH>N2>F1>LEH) suggestive of additive effects of multiple genes. Here, we assessed the neurochemical bases for these heritable Strain Differences by measuring tissue levels of dopamine, serotonin (5HT) and their respective metabolites in several forebrain regions after vehicle, APO or AMPH administration. SDH rats were more sensitive than LEH rats to the PPI-disruptive effects of both APO (0.5 mg/kg) and AMPH (4.5 mg/kg). Several significant SDH vs. LEH Strain Differences in regional neurochemical levels were detected, as were drug effects on these chemicals. However, SDH, LEH and F1 rats did not exhibit differential drug sensitivity in any neurochemical indices measures. These findings suggest that inherited Differences in the dopaminergic regulation of sensorimotor gating do not likely reflect Differences in presynaptic forebrain dopaminergic or serotonergic processes.
Toshiki Sudo - One of the best experts on this subject based on the ideXlab platform.
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Genetic Strain Differences in platelet aggregation and thrombus formation of laboratory rats
Thrombosis and haemostasis, 2007Co-Authors: Toshiki Sudo, Hideki Ito, Hideki Hayashi, Yoshie Nagamura, Kazuyuki Toga, Yoshihisa YamadaAbstract:Rats are employed to investigate the role of platelets in thrombus formation under flow conditions in vivo and to evaluate the pre-clinical potential of antiplatelet drugs. While Wistar and Sprague-Dawley (SD) Strains are commonly used in thrombosis models, a number of rat Strains have been established. Each Strain possesses genetically unique characteristics such as hypertension, hyperglycemia or hyperlipidemia.The appropriate selection of a Strain might have advantages for physiological and pharmacological studies.Comparative investigation of platelet aggregation among laboratory Strains of rats is useful for the development of thrombosis models. In the present study, platelet aggregation response in eight laboratory rat Strains, ACI, Brown Norway (BN), Donryu, Fischer 344 (F344), LEW, SD,Wistar and WKAH, were compared. Considerable Strain Differences were observed in ADP-, collagen- and TRAP-induced platelet aggregation. SD and BN are high-platelet-aggregation Strains, while F344 and ACI are low-response Strains. In the arteriovenous shunt thrombosis model, SD formed larger thrombi than F344 andWistar rats.In the FeCl3-induced thrombosis model with the carotid artery, the time to occlusion of SD was significantly shorter than of F344 and ACI rats. F344 and ACI rats had significantly increased bleeding times compared with SD rat.The present study demonstrates that there are considerable Strain Differences in platelet aggregation among laboratory rats, which reflect thrombus formation.
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Genetic Strain Differences in platelet aggregation of laboratory mice
Thrombosis and haemostasis, 2006Co-Authors: Toshiki Sudo, Hideki Ito, Yukio KimuraAbstract:To investigate the physiological role of novel genes and proteins in platelet activation, various knockout mice have been produced. A number of standard inbred mouse Strains each possessing genetically unique characters such as high tumor generation, hyperglycemia or hyperlipidemia, have been bred. In breeding knockout mice for investigation of specific physiological functions, appropriate selection of parental or backcross Strains is necessary. Thus, examination of Strain-specific platelet characteristics is important.In the present study,platelet aggregation responses of 13 laboratory mouse Strains, 129/Sv, A, AKR, BALB/c, C3H/He, C57BL/6J, CBA, DBA/1, DBA/2, ddY, FVB, ICR, and NZW, and the diabetic Strain C57BL/KsJ db/db, were compared.Marked Strain Differences were observed inADP- and collagen- induced platelet aggregation.The highest responses with both were seen inAKR/J and NZW/N,whereas the lowest were seen in DBA/2 and DBA/1.There was a 5-fold difference in the platelet aggregation threshold index (PATI) for ADP-induced PRP aggregation between AKR/J (0.6 µM) and DBA/2 (3.0 µM). With whole blood aggregation,the highest response was seen in AKR, whereas the lowest was seen in DBA/2 and DBA/1. The present study demonstrated that there is considerable Strain difference in platelet aggregation among laboratory mice, which should be taken into account in backcrossing knockout Strains.
Richard E. Brown - One of the best experts on this subject based on the ideXlab platform.
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what are we measuring when we test Strain Differences in anxiety in mice
Behavior Genetics, 2013Co-Authors: Timothy P Oleary, Rhian K. Gunn, Richard E. BrownAbstract:We examined measures of locomotor and anxiety-like behavior in male and female mice of 15 inbred Strains on the elevated-plus maze, light/dark transition box and open field. Strain Differences were found on all measures of locomotor activity and anxiety. Strain means for measures of locomotor activity on the three apparatus were significantly correlated, but Strain means for commonly used measures of anxiety were not correlated. Principal component analysis revealed a common locomotor activity factor, which accounted for 28.6 % of the variance, but no common anxiety factor. Species-typical behaviors (defecations, stretch-attend postures, grooming) accounted for smaller proportions (<11 %) of the variance. These results plus comparisons with previously published data suggest that the elevated-plus maze, light/dark box and open field measure different facets of anxiety, and that the reliability of genetic Differences on anxiety is highly dependent on apparatus, procedural variables and laboratory factors. Locomotor activity, however, is a stable trait that differs across Strains and is reliably measured in different apparatus and laboratories. We conclude that anxiety traits of inbred mouse Strains are best reflected by species-typical behaviors in each apparatus. These results suggest that new ways of measuring trait anxiety are required in order to determine the neural and genetic correlates of anxiety-like behaviour in mice.
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What are We Measuring When We Test Strain Differences in Anxiety in Mice?
Behavior Genetics, 2013Co-Authors: Timothy P. O’leary, Rhian K. Gunn, Richard E. BrownAbstract:We examined measures of locomotor and anxiety-like behavior in male and female mice of 15 inbred Strains on the elevated-plus maze, light/dark transition box and open field. Strain Differences were found on all measures of locomotor activity and anxiety. Strain means for measures of locomotor activity on the three apparatus were significantly correlated, but Strain means for commonly used measures of anxiety were not correlated. Principal component analysis revealed a common locomotor activity factor, which accounted for 28.6 % of the variance, but no common anxiety factor. Species-typical behaviors (defecations, stretch-attend postures, grooming) accounted for smaller proportions (
Jody M. Shoemaker - One of the best experts on this subject based on the ideXlab platform.
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Neurochemical analysis of rat Strain Differences in the startle gating-disruptive effects of dopamine agonists.
Pharmacology biochemistry and behavior, 2004Co-Authors: Neal R. Swerdlow, Ronald Kuczenski, Jana Goins, Sarah Crain, Lillian T., Michele J. Bongiovanni, Jody M. ShoemakerAbstract:The disruption of prepulse inhibition (PPI) in rats by dopamine (DA) agonists is used to study the neural basis of Strain Differences in dopaminergic function. We reported that, compared to Long-Evans (LEH) rats, Sprague-Dawley (SDH) rats are more sensitive to the PPI-disruptive effects of the direct D1/D2 agonist apomorphine (APO) and the indirect DA agonist d-amphetamine (AMPH). This Strain difference is heritable, with PPI drug sensitivity following a generational pattern (SDH>N2>F1>LEH) suggestive of additive effects of multiple genes. Here, we assessed the neurochemical bases for these heritable Strain Differences by measuring tissue levels of dopamine, serotonin (5HT) and their respective metabolites in several forebrain regions after vehicle, APO or AMPH administration. SDH rats were more sensitive than LEH rats to the PPI-disruptive effects of both APO (0.5 mg/kg) and AMPH (4.5 mg/kg). Several significant SDH vs. LEH Strain Differences in regional neurochemical levels were detected, as were drug effects on these chemicals. However, SDH, LEH and F1 rats did not exhibit differential drug sensitivity in any neurochemical indices measures. These findings suggest that inherited Differences in the dopaminergic regulation of sensorimotor gating do not likely reflect Differences in presynaptic forebrain dopaminergic or serotonergic processes.
Jun Yamada - One of the best experts on this subject based on the ideXlab platform.
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Mouse Strain Differences in immobility and sensitivity to fluvoxamine and desipramine in the forced swimming test: analysis of serotonin and noradrenaline transporter binding.
European journal of pharmacology, 2008Co-Authors: Yumi Sugimoto, Yoshinobu Kajiwara, Kazufumi Hirano, Noriko Tagawa, Yoshiharu Kobayashi, Yoshihiro Hotta, Shizuo Yamada, Jun YamadaAbstract:Strain Differences in immobility time in the forced swimming test were investigated in five Strains of mice, namely, ICR, ddY, C57BL/6, DBA/2 and BALB/c mice. There were significant Strain Differences. The immobility times of ICR, ddY and C57BL/6 mice were longer than those of DBA/2 and BALB/c mice. Immobility times were not significantly related to locomotor activity in these Strains. There were also Differences in sensitivity to the selective serotonin reuptake inhibitor (SSRI) fluvoxamine. In ICR, ddY and C57BL/6 mice, fluvoxamine did not affect immobility time, while it reduced the immobility time of DBA/2 and BALB/c mice dose-dependently. The noradrenaline reuptake inhibitor desipramine decreased immobility time in all Strains of mice. Serotonin (5-HT) transporter binding in the brains of all five Strains of mice was also investigated. Analysis of 5-HT transporter binding revealed significant Strain Differences, being lower in DBA/2 and BALB/c mice than in other Strains of mice. The amount of 5-HT transporter binding was correlated to baseline immobility time. However, there was no significant relation between noradrenaline transporter binding and immobility time. These results suggest that the duration of baseline immobility depends on the levels of 5-HT transporter binding, leading to apparent Strain Differences in immobility time in the forced swimming test. Furthermore, Differences in 5-HT transporter binding may cause variations in responses to fluvoxamine.
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Strain Differences of neurosteroid levels in mouse brain.
Steroids, 2006Co-Authors: Noriko Tagawa, Yumi Sugimoto, Jun Yamada, Yoshiharu KobayashiAbstract:Neurosteroids, pregnenolone (Preg), dehydroepiandrosterone (DHEA) and their sulfates (PregS and DHEAS) are reported to exert their modulatory effects of neuronal excitability and synaptic plasticity via amino acid receptors, which affect and regulate the learning and memory process, mood, and depression. Although the brain levels of these steroids have been reported in rodents, the Strain Differences of the levels of these steroids have not been demonstrated. We examined the concentrations of Preg, 17-OH-Preg, DHEA, androstenediol (ADIOL) and their sulfates in whole brains from DBA/2, C57BL/6, BALB/c, ddY and ICR mice, the genetic backgrounds of which are different. No Differences in the brain levels of Preg and DHEA were found among the Strains. In contrast, PregS levels in DBA/2 were significantly lower than in the others, while DHEAS concentrations in DBA/2 were significantly higher than those in other Strains. Strain Differences were found in 17-OH-Preg, ADIOL and 17-OH-PregS but not in ADIOLS levels. The ranges of Preg and PregS levels were the highest among the steroids studied. Further, we measured serum these steroid levels. Although Strain Differences were also found in serum steroids, correlation study between brain and serum levels revealed that brain neurosteroids studied may not come from peripheral circulation. In conclusion, this is the first report of demonstrating mammalian brain levels of 17-OH-Preg, ADIOL, 17-OH-PregS and ADIOLS and the Strain Differences in neurosteroid levels in mice brains. The Differences in levels may involve the Strain Differences in their behavior, e.g. aggression, adaptation to stress or learning, in mice.
