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Line Differences (line + difference)

Distribution by Scientific Domains

Medical Sciences	42%

Selected Abstracts

Selected Line Difference in the Effects of Ethanol Dependence and Withdrawal on Allopregnanolone Levels and 5,-Reductase Enzyme Activity and Expression

ALCOHOLISM, Issue 12 2009
Michelle A. Tanchuck
Background:, Allopregnanolone (ALLO) is a progesterone derivative that rapidly potentiates ,-aminobutyric acidA (GABAA) receptor-mediated inhibition and modulates symptoms of ethanol withdrawal. Because clinical and preclinical data indicate that ALLO levels are inversely related to symptoms of withdrawal, the present studies determined whether ethanol dependence and withdrawal differentially altered plasma and cortical ALLO levels in mice selectively bred for differences in ethanol withdrawal severity and determined whether the alterations in ALLO levels corresponded to a concomitant change in activity and expression of the biosynthetic enzyme 5,-reductase. Methods:, Male Withdrawal Seizure-Prone (WSP) and -Resistant (WSR) mice were exposed to 72 hours ethanol vapor or air and euthanized at select times following removal from the inhalation chambers. Blood was collected for analysis of ALLO and corticosterone levels by radioimmunoassay. Dissected amygdala, hippocampus, midbrain, and cortex as well as adrenals were examined for 5,-reductase enzyme activity and expression levels. Results:, Plasma ALLO was decreased significantly only in WSP mice, and this corresponded to a decrease in adrenal 5,-reductase expression. Cortical ALLO was decreased up to 54% in WSP mice and up to 46% in WSR mice, with a similar decrease in cortical 5,-reductase activity during withdrawal in the lines. While cortical gene expression was significantly decreased during withdrawal in WSP mice, there was a 4-fold increase in expression in the WSR line during withdrawal. Hippocampal 5,-reductase activity and gene expression was decreased only in dependent WSP mice. Conclusions:, These results suggest that there are line and brain regional differences in the regulation of the neurosteroid biosynthetic enzyme 5,-reductase during ethanol dependence and withdrawal. In conjunction with the finding that WSP mice exhibit reduced sensitivity to ALLO during withdrawal, the present results are consistent with the hypothesis that genetic differences in ethanol withdrawal severity are due, in part, to modulatory effects of GABAergic neurosteroids such as ALLO. [source]

Acoustic Startle Reactivity During Acute Alcohol Withdrawal in Rats That Differ in Genetic Predisposition Toward Alcohol Drinking: Effect of Stimulus Characteristics

ALCOHOLISM, Issue 5 2004
Julia A. Chester
Abstract: Background: We have previously reported an association between greater alcohol withdrawal magnitude after a single alcohol exposure and a genetic predisposition toward low alcohol drinking in rats selectively bred for differences in alcohol intake when acoustic startle reactivity to a tone stimulus was used to index acute alcohol withdrawal. The purpose of this study was to examine whether the quality of the acoustic startle stimulus (noise versus tone) is important for detecting a genetic relationship between alcohol withdrawal magnitude and alcohol drinking behavior. Methods: Alcohol-naive male rats selectively bred for high alcohol intake [alcohol-preferring (P), high-alcohol-drinking (HAD)1, and HAD2] or low alcohol intake [alcohol-nonpreferring (NP), low-alcohol-drinking (LAD)1, and LAD2] received a single intragastric infusion of water or alcohol (4.0 g/20.3 ml/kg; 25% v/v), and acoustic startle test sessions were given at 14, 16, 18, 20, and 24 hr after infusion. Each test session consisted of a 5-min acclimation period followed by random presentation of various white noise stimuli (90, 100, 110, and 120 dB.) Results: Line differences in acoustic startle magnitude under control conditions were present in all three pairs of selectively bred lines; P rats showed a greater startle magnitude relative to NP rats, whereas both LAD lines showed a greater startle magnitude relative to both HAD lines. During alcohol withdrawal, the P, HAD1, and HAD2 lines showed enhanced startle magnitude compared with their water-treated controls. No change in startle magnitude during alcohol withdrawal was found in the NP, LAD1, or LAD2 lines. Conclusions: In contrast to our prior findings, these results showed a genetic association between high alcohol drinking and a greater startle response magnitude to a noise stimulus during alcohol withdrawal. It seems that the genetic association between alcohol drinking and alcohol withdrawal, as assessed by the acoustic startle response, depends on the quality of the acoustic startle stimulus. [source]

Brain mitochondrial aldehyde dehydrogenase: relation to acetaldehyde aversion in low-alcohol-drinking (UChA) and high-alcohol-drinking (UChB) rats

ADDICTION BIOLOGY, Issue 4 2003
María elena Quintanilla
Previous reports indicate that the low-drinker (UChA) rats, when compared to high-drinker (UChB) rats, display lower mitochondrial aldehyde dehydrogenase (ALDH2) activity due to a mutation of the Aldh2 gene. Because a later study found line differences in sensitivity to the aversive effects of acetaldehyde (AcH) administered intraperitoneally (i.p.), which were not associated with the line difference detected in blood AcH levels, the present study examined the contribution of brain ALDH2 activity to AcH aversion in UChA and UChB rats. In experiment 1, we established the dose-response curves for AcH aversion (25, 50 or 100 mg/kg i.p.) in rats of both lines by using a conditioned taste aversion (CTA) paradigm. The results confirm our previous finding that UChA and UChB rats presented marked differences in their AcH aversion thresholds, which were not associated with the line differences detected in blood AcH levels. In experiment 2, the possibility that the inhibition of the brain ALDH2 would lower the AcH aversion threshold in both lines was studied by determining the effect of cyanamide (10 mg/kg i.p.) pretreatment, an inhibitor of ALDH, on AcH aversion, blood AcH levels and brain ALDH2 activity. The finding that blocking the brain ALDH2 (52%) by cyanamide can make a non-aversive dose of AcH (25 mg/kg) aversive to UChA and UChB rats at blood AcH levels comparable to those induced by a non-aversive dose of AcH (100 mg/kg) in control UChB rats indicates that the line difference in AcH aversion is associated more with brain ALDH2 activity than with liver ALDH2 activity. [source]

Exploratory behavior in mice selectively bred for developmental differences in aggressive behavior

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2008
Kathryn E. Hood
Abstract The development and expression of exploratory behavior was assessed in the Cairns lines of Institute for Cancer Research (ICR) mice that were selectively bred for differences in aggressive behavior, with a high-aggressive 900 line, low-aggressive 100 line, and control 500 line. Four paradigms were employed. Developmental changes were evident in the complex novel arena, with older males faster to contact a novel object, and ambulating more than young males. Within the control 500 line, older males showed longer latency to emerge from the home cage, and shorter latency to contact novel objects. In the 900 line, younger males showed this same pattern. R. B. Cairns proposed that line differences in aggressive behavior arise through alterations in developmental timing [Cairns et al. [1983] Life-span developmental psychology (Vol. 5). New York: Academic Press; Gariépy et al. [2001] Animal Behaviour 61: 933,947]. The early appearance of mature patterns of exploratory behavior in 900 line males supports this interpretation. The 900 line males also appear to be behaviorally inhibited in novel settings such as the light,dark box and the neohypophagia paradigm, compared to the 500 and 100 lines (Experiments 1, 2, and 4). Moreover, in the most complex apparatus, the novel arena, 900 line males were slowest to exit the home cage, and fastest to contact a novel object. The apparent contrast in these parameters of exploratory behavior is discussed in relation to T. C. Schneirla's [1965 Advances in the study of behavior (Vol. 1). New York: PN Academic] approach,withdrawal theory. © 2007 Wiley Periodicals, Inc. Dev Psychobiol 50: 32,47, 2008. [source]

Maternal behavior changes after immune challenge of neonates with developmental effects on adult social behavior

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2003
Kathryn E. Hood
Abstract To examine whether maternal responsiveness during interactions with endotoxin-treated pups contributes to long-term effects on social development, neonatal mice were fostered on postnatal day 1 to dams from three selectively bred lines that differ in social behaviors. On day 5, neonates were administered saline or 0.5 mg/kg endotoxin (lipopolysaccharide, i.p.). Observations of undisturbed dams and litters on days 2, 4, 6, and 8 showed modest line differences in maternal behaviors. At the peak intensity of the transient illness induced by endotoxin (3 hr postinjection on day 5), dams increased licking and decreased time off-nest for endotoxin, but not saline-treated pups. As adults, fostered-reared males were observed in brief social interactions. Males exposed to endotoxin early in life showed changes in adult social behaviors that depended on foster dam line as well as individual differences in maternal responsiveness. Maternal responsiveness to stressed neonates can ameliorate the social,developmental effects of early illness. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 17,34, 2003. [source]

Brain mitochondrial aldehyde dehydrogenase: relation to acetaldehyde aversion in low-alcohol-drinking (UChA) and high-alcohol-drinking (UChB) rats

Differential Effects of Stress on Adult Hippocampal Cell Proliferation in Low and High Aggressive Mice

JOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2007
A. H. Veenema
Male wild house mice selected for a long (LAL) or a short (SAL) latency to attack a male intruder generally show opposing behavioural coping responses to environmental challenges. LAL mice, unlike SAL mice, adapt to novel challenges with a highly reactive hypothalamic-pituitary-adrenal axis and show an enhanced expression of markers for hippocampal plasticity. The present study aimed to test the hypothesis that these features of the more reactive LAL mice are reflected in parameters of hippocampal cell proliferation. The data show that basal cell proliferation in the subgranular zone (SGZ) of the dentate gyrus, assessed by the endogenous proliferation marker Ki-67, is lower in LAL than in SAL mice. Furthermore, application of bromodeoxyuridine (BrdU) over 3 days showed an almost two-fold lower cell proliferation rate in the SGZ in LAL versus SAL mice. Exposure to forced swimming resulted, 24 h later, in a significant reduction in BrdU + cell numbers in LAL mice, whereas cell proliferation was unaffected by this stressor in SAL mice. Plasma corticosterone and dentate gyrus glucocorticoid receptor levels were higher in LAL than in SAL mice. However, no differences between the SAL and LAL lines were found for hippocampal NMDA receptor binding. In conclusion, the data suggest a relationship between coping responses and hippocampal cell proliferation, in which corticosterone may be one of the determinants of line differences in cell proliferation responses to environmental challenges. [source]