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John C. Crabbe - One of the best experts on this subject based on the ideXlab platform.
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affective behavior in Withdrawal Seizure prone and Withdrawal Seizure resistant mice during long term alcohol abstinence
Alcoholism: Clinical and Experimental Research, 2019Co-Authors: Matthew C Hartmann, John C. Crabbe, Sarah E Holbrook, Megan M Haney, Alan M RosenwasserAbstract:Background While the acute alcohol Withdrawal syndrome has been well characterized both in human clinical studies and in experimental animals, much less is known regarding long-term affective disturbances that can sometimes persist during protracted abstinence. Nevertheless, since relapse often occurs long after acute detoxification and may be predicted by persistent affective disruption, a better understanding of the long-term behavioral consequences of prior alcohol dependence may lead to improved strategies for relapse prevention. Methods Male and female Withdrawal Seizure-Prone and Withdrawal Seizure-Resistant mice from the second selection replicate (WSP-2, WSR-2) were exposed to a 10-day chronic-intermittent ethanol vapor protocol (CIE) or plain air and then tested repeatedly on the sucrose preference test (SPT), marble burying test (MBT), and the light-dark box test (LDT) over 7 weeks of (forced) abstinence. Results While WSP and WSR mice differed significantly on tests of anxiety-like behavior (LDT, MBT), we found little evidence for long-term affective disruption following CIE in either line. The major exception was in the LDT, in that WSP but not WSR mice displayed longer latencies to enter the light compartment following CIE relative to air-controls. Conclusions Selective breeding for acute Withdrawal severity has resulted in differences in anxiety-like behavior between WSP and WSR mice. In contrast, however, genes contributing to the severity of acute Withdrawal convulsions appear to have little overlap with those predisposing to affective disruption during long-term abstinence.
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Table_1_Stable Histone Methylation Changes at Proteoglycan Network Genes Following Ethanol Exposure.DOCX
2018Co-Authors: David P. Gavin, John C. Crabbe, Joel G. Hashimoto, Nathan H. Lazar, Lucia Carbone, Marina GuizzettiAbstract:Alcohol use disorder (AUD) is a chronic mental illness in which patients often achieve protracted periods of abstinence prior to relapse. Epigenetic mechanisms may provide an explanation for the persisting gene expression changes that can be observed even after long periods of abstinence and may contribute to relapse. In this study, we examined two histone modifications, histone 3 lysine 4 tri-methylation (H3K4me3) and histone 3 lysine 27 tri-methylation (H3K27me3), in the prefrontal cortex of Withdrawal Seizure Resistant (WSR) mice 21 days after 72 h of ethanol vapor exposure. These histone modifications were selected because they are associated with active promoters (H3K4me3) and repressed gene expression in a euchromatic environment (H3K27me3). We performed a genome-wide analysis to identify differences in H3K4me3 and H3K27me3 levels in post-ethanol exposure vs. control mice by ChIP-seq. We detected a global reduction in H3K4me3 peaks and increase in H3K27me3 peaks in post-ethanol exposure mice compared to controls, these changes are consistent with persistent reductions in gene expression. Pathway analysis of genes displaying changes in H3K4me3 and H3K27me3 revealed enrichment for genes involved in proteoglycan and calcium signaling pathways, respectively. Microarray analysis of 7,683 genes and qPCR analysis identified eight genes displaying concordant regulation of gene expression and H3K4me3/H3K27me3. We also compared changes in H3K4me3 and/or H3K27me3 from our study with changes in gene expression in response to ethanol from published literature and we found that the expression of 52% of the genes with altered H3K4me3 binding and 40% of genes with H3K27me3 differences are altered by ethanol exposure. The chromatin changes associated with the 21-day post-exposure period suggest that this period is a unique state in the addiction cycle that differs from ethanol intoxication and acute Withdrawal. These results provide insights into the enduring effects of ethanol on proteoglycan and calcium signaling genes in the brain.
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Quantification of ten neuroactive steroids in plasma in Withdrawal Seizure-Prone and -Resistant mice during chronic ethanol Withdrawal
Psychopharmacology, 2014Co-Authors: Christopher Snelling, John C. Crabbe, Michelle A. Tanchuck-nipper, Matthew M. Ford, Jeremiah P. Jensen, Debra K. Cozzoli, Marcia J. Ramaker, Melinda Helms, David J. Rossi, Deborah A FinnAbstract:Rationale The rapid membrane actions of neuroactive steroids, particularly via an enhancement of γ-aminobutyric acid_A receptors (GABA_ARs), participate in the regulation of central nervous system excitability. Prior evidence suggests an inverse relationship between endogenous GABAergic neuroactive steroid levels and behavioral changes in excitability during ethanol Withdrawal. Objectives Previously, we found that ethanol Withdrawal significantly decreased plasma allopregnanolone (ALLO) levels, a potent GABAergic neuroactive steroid, and decreased GABA_AR sensitivity to ALLO in Withdrawal Seizure-Prone (WSP) but not in Withdrawal Seizure-Resistant (WSR) mice. However, the effect of ethanol Withdrawal on levels of other endogenous GABA_AR-active steroids is not known. Methods After validation of a gas chromatography-mass spectrometry method for the simultaneous quantification of ten neuroactive steroids, we analyzed plasma from control male WSP-1 and WSR-1 mice and during ethanol Withdrawal. Results We quantified levels of nine neuroactive steroids in WSP-1 and WSR-1 plasma; levels of pregnanolone were not detectable. Basal levels of five neuroactive steroids were higher in WSR-1 versus WSP-1 mice. Ethanol Withdrawal significantly suppressed five neuroactive steroids in WSP-1 and WSR-1 mice, including ALLO. Conclusions Due to lower basal levels of some GABA_AR-active steroids in WSP-1 mice, a Withdrawal-induced decrease in WSP-1 mice may have a greater physiological consequence than a similar decrease in WSR-1 mice. Because WSP-1 mice also exhibit a reduction in GABA_AR sensitivity to neuroactive steroids during Withdrawal, it is possible that the combined decrease in neuroactive steroids and GABA_AR sensitivity during ethanol Withdrawal in WSP-1 mice represents a neurochemical substrate for severe ethanol Withdrawal.
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ethanol drinking in Withdrawal Seizure prone and resistant selected mouse lines
Alcohol, 2013Co-Authors: John C. Crabbe, Stephanie E Spence, Lawrence C Huang, Andy J Cameron, Jason P Schlumbohm, Amanda M Barkleylevenson, Pamela MettenAbstract:Withdrawal Seizure-Prone (WSP) and Withdrawal Seizure-Resistant (WSR) mouse lines were bidirectionally selectively bred, respectively, to have severe or mild ethanol Withdrawal handling-induced convulsions (HICs) after cessation of 3 days of ethanol vapor inhalation. Murine genotypes with severe Withdrawal have been found to show low ethanol consumption, and high consumers show low Withdrawal. An early drinking study with WSP and WSR mice showed modest evidence consistent with this genetic correlation, but there were several limitations to that experiment. We therefore conducted a thorough assessment of two bottle ethanol preference drinking in both replicate pairs of WSP/WSR selected lines in mice of both sexes. Greater preference drinking of WSR-2 than WSP-2 female mice confirmed the earlier report. However, in the parallel set of selected lines, the WSP-1 mice drank more than the WSR-1s. Naive mice tested for preference for sucrose, saccharin and quinine did not differ markedly for any tastant. Finally, in a test of binge-like drinking, Drinking in the Dark (DID), WSP mice drank more than WSR mice and attained significantly higher (but still modest) blood ethanol concentrations. Tests of acute Withdrawal after DID showed a mild, but significant elevation in handling-induced convulsions in the WSP line. These results provide further evidence that 2-bottle ethanol preference and DID are genetically distinguishable traits.
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local changes in neurosteroid levels in the substantia nigra reticulata and the ventral tegmental area alter chronic ethanol Withdrawal severity in male Withdrawal Seizure prone mice
Alcoholism: Clinical and Experimental Research, 2013Co-Authors: Michelle A Tanchuck, John C. Crabbe, Katherine R Kaufman, Christopher Snelling, Debra K. Cozzoli, Gregory P Mark, Deborah A FinnAbstract:Background Allopregnanolone (ALLO) is a potent positive modulator of γ-aminobutyric acidA receptors (GABAARs) that affects ethanol (EtOH) Withdrawal. Finasteride (FIN), a 5α-reductase inhibitor that blocks the formation of ALLO and other GABAergic neurosteroids, alters EtOH sensitivity. Recently, we found that Withdrawal Seizure-Prone mice from the first genetic replicate (WSP-1) exhibited behavioral tolerance to the anticonvulsant effect of intrahippocampal ALLO during EtOH Withdrawal and that intrahippocampal FIN significantly increased EtOH Withdrawal severity. The purpose of this study was to determine whether neurosteroid manipulations in the substantia nigra reticulata (SNR) and ventral tegmental area (VTA) produced effects during EtOH Withdrawal comparable to those seen with intrahippocampal ALLO and FIN. Methods Male WSP-1 mice were surgically implanted with bilateral guide cannulae aimed at the SNR or VTA at 2 weeks prior to EtOH vapor or air exposure for 72 hours. Initial studies examined the anticonvulsant effect of a single ALLO infusion (0, 100, or 400 ng/side) at a time corresponding to peak Withdrawal in the air- and EtOH-exposed mice. Separate studies examined the effect of 4 FIN infusions (0 or 10 μg/side/d) during the development of physical dependence on the expression of EtOH Withdrawal. Results ALLO infusion exerted a potent anticonvulsant effect in EtOH-naive mice, but a diminished anticonvulsant effect during EtOH Withdrawal. Administration of FIN into the SNR exerted a delayed proconvulsant effect in EtOH-naive mice, whereas infusion into the VTA increased EtOH Withdrawal duration. Conclusions Activation of local GABAARs in the SNR and VTA via ALLO infusion is sufficient to exert an anticonvulsant effect in naive mice and to produce behavioral tolerance to the anticonvulsant effect of ALLO infusion during EtOH Withdrawal. Thus, EtOH Withdrawal reduced sensitivity of GABAARs to GABAergic neurosteroids in 2 neuroanatomical substrates within the basal ganglia in WSP-1 male mice.
Deborah A Finn - One of the best experts on this subject based on the ideXlab platform.
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Genetic Differences in Behavioral Sensitivity to a Neuroactive Steroid
2020Co-Authors: Deborah A Finn, Amanda J Roberts, Frank Lotrich, Edward J GallaherAbstract:ABSTRACT Recent work found that lower endogenous levels of the ␥-aminobutyric acid-agonist, neuroactive steroid 3␣-hydroxy-5␣-pregnan-20-one (3␣,5␣-THP) may be correlated with increased ethanol Withdrawal severity in the selectively bred Withdrawal Seizure-Prone and -Resistant mice. The present studies were conducted to determine whether decreased sensitivity to 3␣,5␣-THP was correlated with ethanol Withdrawal hyperexcitability in another genetic mouse model, namely the C57BL/6 (B6) and DBA/2 (D2) inbred strains. These strains also differ in ethanol Withdrawal severity (D2 Ͼ Ͼ B6). B6 and D2 male mice were injected with 3␣,5␣-THP (0 -10 mg/kg i.p.) 15 min before the timed tail vein infusion of pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anticonvulsant effect of 3␣,5␣-THP. Subsequent studies measured sensitivity to several of the pharmacological effects of 3␣,5␣-THP. B6 and D2 male mice were injected with 3␣,5␣-THP (0 -32 mg/kg) before testing for locomotor activation (total number of entries) and anxiolysis (percent open arm entries) on the elevated plus maze, muscle relaxation (impairment of forelimb grip strength), ataxia (impairment of Rotarod performance) and Seizure susceptibility to pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anxiolytic, locomotor stimulant and anticonvulsant effects of 3␣,5␣-THP. In contrast, D2 mice were more sensitive than B6 mice to 3␣,5␣-THP-induced muscle relaxation and ataxia. Plasma 3␣,5␣-THP levels did not differ in the B6 and D2 mice injected with this steroid, suggesting that the strain differences were not pharmacokinetic. Collectively, the results in selectively bred Withdrawal Seizure-Prone and -Resistant mice and B6 and D2 inbred strains suggest that genetic differences in neuroactive steroid sensitivity and biosynthesis may contribute to ethanol Withdrawal severity
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Quantification of ten neuroactive steroids in plasma in Withdrawal Seizure-Prone and -Resistant mice during chronic ethanol Withdrawal
Psychopharmacology, 2014Co-Authors: Christopher Snelling, John C. Crabbe, Michelle A. Tanchuck-nipper, Matthew M. Ford, Jeremiah P. Jensen, Debra K. Cozzoli, Marcia J. Ramaker, Melinda Helms, David J. Rossi, Deborah A FinnAbstract:Rationale The rapid membrane actions of neuroactive steroids, particularly via an enhancement of γ-aminobutyric acid_A receptors (GABA_ARs), participate in the regulation of central nervous system excitability. Prior evidence suggests an inverse relationship between endogenous GABAergic neuroactive steroid levels and behavioral changes in excitability during ethanol Withdrawal. Objectives Previously, we found that ethanol Withdrawal significantly decreased plasma allopregnanolone (ALLO) levels, a potent GABAergic neuroactive steroid, and decreased GABA_AR sensitivity to ALLO in Withdrawal Seizure-Prone (WSP) but not in Withdrawal Seizure-Resistant (WSR) mice. However, the effect of ethanol Withdrawal on levels of other endogenous GABA_AR-active steroids is not known. Methods After validation of a gas chromatography-mass spectrometry method for the simultaneous quantification of ten neuroactive steroids, we analyzed plasma from control male WSP-1 and WSR-1 mice and during ethanol Withdrawal. Results We quantified levels of nine neuroactive steroids in WSP-1 and WSR-1 plasma; levels of pregnanolone were not detectable. Basal levels of five neuroactive steroids were higher in WSR-1 versus WSP-1 mice. Ethanol Withdrawal significantly suppressed five neuroactive steroids in WSP-1 and WSR-1 mice, including ALLO. Conclusions Due to lower basal levels of some GABA_AR-active steroids in WSP-1 mice, a Withdrawal-induced decrease in WSP-1 mice may have a greater physiological consequence than a similar decrease in WSR-1 mice. Because WSP-1 mice also exhibit a reduction in GABA_AR sensitivity to neuroactive steroids during Withdrawal, it is possible that the combined decrease in neuroactive steroids and GABA_AR sensitivity during ethanol Withdrawal in WSP-1 mice represents a neurochemical substrate for severe ethanol Withdrawal.
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local changes in neurosteroid levels in the substantia nigra reticulata and the ventral tegmental area alter chronic ethanol Withdrawal severity in male Withdrawal Seizure prone mice
Alcoholism: Clinical and Experimental Research, 2013Co-Authors: Michelle A Tanchuck, John C. Crabbe, Katherine R Kaufman, Christopher Snelling, Debra K. Cozzoli, Gregory P Mark, Deborah A FinnAbstract:Background Allopregnanolone (ALLO) is a potent positive modulator of γ-aminobutyric acidA receptors (GABAARs) that affects ethanol (EtOH) Withdrawal. Finasteride (FIN), a 5α-reductase inhibitor that blocks the formation of ALLO and other GABAergic neurosteroids, alters EtOH sensitivity. Recently, we found that Withdrawal Seizure-Prone mice from the first genetic replicate (WSP-1) exhibited behavioral tolerance to the anticonvulsant effect of intrahippocampal ALLO during EtOH Withdrawal and that intrahippocampal FIN significantly increased EtOH Withdrawal severity. The purpose of this study was to determine whether neurosteroid manipulations in the substantia nigra reticulata (SNR) and ventral tegmental area (VTA) produced effects during EtOH Withdrawal comparable to those seen with intrahippocampal ALLO and FIN. Methods Male WSP-1 mice were surgically implanted with bilateral guide cannulae aimed at the SNR or VTA at 2 weeks prior to EtOH vapor or air exposure for 72 hours. Initial studies examined the anticonvulsant effect of a single ALLO infusion (0, 100, or 400 ng/side) at a time corresponding to peak Withdrawal in the air- and EtOH-exposed mice. Separate studies examined the effect of 4 FIN infusions (0 or 10 μg/side/d) during the development of physical dependence on the expression of EtOH Withdrawal. Results ALLO infusion exerted a potent anticonvulsant effect in EtOH-naive mice, but a diminished anticonvulsant effect during EtOH Withdrawal. Administration of FIN into the SNR exerted a delayed proconvulsant effect in EtOH-naive mice, whereas infusion into the VTA increased EtOH Withdrawal duration. Conclusions Activation of local GABAARs in the SNR and VTA via ALLO infusion is sufficient to exert an anticonvulsant effect in naive mice and to produce behavioral tolerance to the anticonvulsant effect of ALLO infusion during EtOH Withdrawal. Thus, EtOH Withdrawal reduced sensitivity of GABAARs to GABAergic neurosteroids in 2 neuroanatomical substrates within the basal ganglia in WSP-1 male mice.
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sex differences in acute ethanol Withdrawal severity after adrenalectomy and gonadectomy in Withdrawal Seizure prone and Withdrawal Seizure resistant mice
Alcohol, 2009Co-Authors: Moriah N Strong, John C. Crabbe, Deborah A Finn, Katherine R KaufmanAbstract:Recent findings suggest that the ability of ethanol (EtOH) to increase the levels of neurosteroids with potent γ-aminobutyric acid (GABA)ergic properties can influence measures of EtOH sensitivity. Earlier studies determined that removal of the adrenals and gonads diminished the steroidogenic effect of EtOH and significantly increased acute EtOH Withdrawal severity in two inbred mouse strains that differed in Withdrawal severity, suggesting the contribution of anticonvulsant GABAergic steroids to acute Withdrawal in intact animals. Thus, the goal of the present studies was to investigate the consequence of steroid removal on acute EtOH Withdrawal through excision of the adrenals and gonads, in another genetic animal model of EtOH Withdrawal differences, the Withdrawal Seizure-Prone (WSP) and -Resistant (WSR) selected lines. Male and female WSP and WSR mice underwent surgical removal of the adrenals and gonads or no organ removal (SHAM). One to two weeks later, baseline handling-induced convulsions (HICs) were assessed, mice were given a 4 g/kg dose of ethanol, and HICs were measured hourly for 12 hours and then at 24 hours. The combination surgery significantly increased EtOH Withdrawal in WSP and WSR female mice, as measured by area under the curve (AUC) and peak HIC scores. AUC was significantly positively correlated with plasma corticosterone levels and significantly negatively correlated with progesterone levels. In contrast, surgical status did not alter Withdrawal severity in male WSP and WSR mice. Overall, the increase in acute ethanol Withdrawal severity in female WSP and WSR mice following adrenalectomy and gonadectomy corroborate our recent evidence that Withdrawal from a high dose of EtOH can be modulated by anticonvulsant steroids produced in the periphery.
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decreased anticonvulsant efficacy of allopregnanolone during ethanol Withdrawal in female Withdrawal Seizure prone vs Withdrawal Seizure resistant mice
Neuropharmacology, 2008Co-Authors: Ethan H Beckley, John C. Crabbe, Deborah A Finn, Andrea M Fretwell, Michelle A Tanchuck, Katherine R GilillandAbstract:Abstract The GABAergic neurosteroid allopregnanolone (ALLO) has been repeatedly shown to have an increased anticonvulsant effect during ethanol Withdrawal in rats and in C57BL/6J mice. In contrast, the Seizure prone DBA/2J inbred strain and the Withdrawal Seizure-Prone (WSP) selected line exhibited decreased sensitivity to ALLO’s anticonvulsant effect during ethanol Withdrawal, with no change in sensitivity in the Withdrawal Seizure-Resistant (WSR) line. To date, only male mice have been tested. Thus, the present study examined ALLO sensitivity during ethanol Withdrawal in female WSP and WSR mice, since females display less severe physical symptoms of Withdrawal and have higher circulating ALLO levels than males. Female WSP and WSR mice were exposed to ethanol vapor or air for 72 h. During peak ethanol Withdrawal, separate groups of mice were injected with vehicle or ALLO (0, 3.2, 10, or 17 mg/kg, i.p.) prior to the timed tail vein infusion of pentylenetetrazol (PTZ). ALLO injection significantly increased the threshold dose for onset to PTZ-induced convulsions, indicating an anticonvulsant effect, in female WSP and WSR mice. During ethanol Withdrawal, sensitivity to ALLO’s anticonvulsant effect was slightly increased in female WSR mice but was significantly decreased in female WSP mice. This line difference in sensitivity to ALLO during ethanol Withdrawal in female mice was similar to that in the male mice. Notably, all Seizure prone genotypes tested to date displayed tolerance to the anticonvulsant effect of ALLO during ethanol Withdrawal, suggesting that decreased sensitivity of GABA A receptors to ALLO may contribute to the increased ethanol Withdrawal phenotype.
Adron R Harris - One of the best experts on this subject based on the ideXlab platform.
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modulation of γ aminobutyric acida receptor operated chloride channels by benzodiazepine inverse agonists is related to genetic differences in ethanol Withdrawal Seizure severity
Journal of Neurochemistry, 1991Co-Authors: Kari J Buck, Susan J Mcquilkin, Adron R HarrisAbstract:To determine whether genetic differences in development of ethanol dependence are related to changes in gamma-aminobutyric acidA (GABAA) receptor function, we measured 36Cl- uptake by brain cortical membrane vesicles from Withdrawal Seizure prone and Withdrawal Seizure resistant (WSP/WSR) mice treated chronically with ethanol. Muscimol-stimulated chloride flux was not different between WSP and WSR mice before or after ethanol treatment. Also, augmentation of muscimol action by flunitrazepam or inhibition of muscimol action by the inverse agonists Ro 15-4513 (ethyl-8-azido-5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5a]- [1,4]benzodiazepine-3-carboxylate) and methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) was not different for ethanol-naive WSP and WSR mice. However, chronic ethanol administration enhanced the inhibitory actions of DMCM and Ro 15-4513 on membranes from WSP but not WSR mice. Conversely, chronic ethanol treatment attenuated the action of flunitrazepam on membranes from WSR but not WSP mice, suggesting that the actions of benzodiazepine agonists and inverse agonists are under separate genetic control. These genetic differences in actions of DMCM and Ro 15-4513 indicate that sensitization to benzodiazepine inverse agonists produced by chronic ethanol treatment may be related to development of Withdrawal Seizures and suggest that differences in the GABA/benzodiazepine receptor complex represent alleles that have segregated during the selection of the WSP/WSR mice.
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chronic ethanol treatment alters brain levels of γ aminobutyric acida receptor subunit mrnas relationship to genetic differences in ethanol Withdrawal Seizure severity
Journal of Neurochemistry, 1991Co-Authors: Kari J Buck, Lisa Hahner, James M Sikela, Adron R HarrisAbstract:Chronic ethanol treatment is known to alter the function of the gamma-aminobutyric acidA (GABAA) benzodiazepine receptor complex. To determine if genetic differences in development of ethanol dependence are related to expression of GABAA receptor subunits, we measured whole brain levels of mRNA for the alpha 1, alpha 3, alpha 6, gamma 2s, gamma 2L, and gamma 3 receptor subunits in Withdrawal Seizure-prone and -resistant (WSP and WSR, respectively) mice fed an ethanol-containing liquid diet or a control diet. Brain poly(A)+ RNA was converted to cDNA and amplified by the polymerase chain reaction using primers conserved among GABAA receptor subunits. Quantification was carried out by densitometric analysis of Southern blots generated using subunit-specific probes. Chronic ethanol treatment decreased the content of alpha 1 mRNA in WSP but not WSR mice and decreased the content of alpha 6 mRNA in WSR but not WSP mice. The content of gamma 3 mRNA was increased by chronic ethanol in both lines. In untreated mice, the WSP line had lower levels of alpha 3 and alpha 6 mRNA than the WSR line. Thus, a decrease in the content of alpha 1 mRNA is most clearly linked with development of Withdrawal signs, although the amounts of alpha 6 and alpha 3 may also be important in the genetic differences between WSP and WSR mice. In contrast, levels of mRNA for gamma 2S and gamma 2L subunits do not appear to be altered in ethanol dependence.
Aaron Janowsky - One of the best experts on this subject based on the ideXlab platform.
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allosteric regulation of the n methyl d aspartate receptor linked ion channel complex and effects of ethanol in ethanol Withdrawal Seizure prone and resistant mice
Journal of Neurochemistry, 2002Co-Authors: Leslie A Carter, John C. Crabbe, John K Belknap, Aaron JanowskyAbstract:The effects of ethanol, glycine, and spermidine on the specific binding of [3H]MK-801 were characterized in Triton-treated membranes prepared from the hippocampus and cortex of ethanol-Withdrawal Seizure-prone (WSP) and -resistant (WSR) mice. Glycine, an allosteric agonist at the NMDA receptor-linked ion channel complex, caused an increase in specific [3H]MK-801 binding to hippocampal membrane preparations. There were no significant differences in EC50 values between the selected lines for the effect of glycine (WSP, 391.7 +/- 48.4 nM; WSR, 313.4 +/- 77 nM) in the presence of 10 microM NMDA or in the maximal response to the agonist (WSP, 1.75 +/- 0.26 pmol/mg of protein; WSR, 1.67 +/- 0.22 pmol/mg of protein). The EC50 values for the spermidine-induced increase in [3H]MK-801 binding in membranes from hippocampus in the absence (WSP, 11.7 +/- 0.83 microM; WSR, 9.98 +/- 1.29 microM) or in the presence of 10 microM glycine and 10 microM NMDA (WSP, 2.1 +/- 0.35 microM; WSR, 2.37 +/- 0.42 microM) also did not differ. Similar results were obtained in cortical membranes. Saturation isotherms indicated that there was no difference in the density of [3H]MK-801 binding sites, or in their affinity for the radioligand, between the mouse lines. In addition, administration of ethanol by inhalation (24 h) to WSP and WSR mice did not cause an increase in the density of [3H]MK-801 binding sites, and there was no difference in the density or affinity of binding sites between the mouse lines.(ABSTRACT TRUNCATED AT 250 WORDS)
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nmda receptor subunit mrna and protein expression in ethanol Withdrawal Seizure prone and resistant mice
Alcoholism: Clinical and Experimental Research, 2001Co-Authors: John N Mason, John C. Crabbe, Amy J Eshleman, John K Belknap, Jennifer M Loftis, Tara A Macey, Aaron JanowskyAbstract:Background: Ethanol Withdrawal Seizure-prone (WSP) and -resistant (WSR) mice have been genetically selected for differences in handling-induced convulsion severity during Withdrawal from chronic ethanol administration. Importantly, drug-naive mice from these selected lines also differ in handling-induced convulsion severity. Different N-methyl-D-aspartate (NMDA) receptor subunit and splice variant associations confer varying sensitivities to ethanol, and may play a role in the different behavioral responses of the WSP and WSR mice. Methods: In situ hybridization of riboprobes was used to characterize NMDA receptor subunit and splice variant mRNA expression in cortex and hippocampus from WSP and WSR mice. In addition, immunoblotting and immunohistochemistry were used to examine the expression of specific NMDA receptor subunits and splice variants in hippocampus and cortex from the selected mouse lines. Results: In situ hybridization of riboprobes indicated that, in brain sections from both WSP and WSR mice, there was a differential regional distribution of mRNA for the mouse NR1, NR2A, NR2B, and NR2C NMDA receptor subunits. However, there were no differences between the selected lines in the hybridization of riboprobes to hippocampal subfields or cortical layers. In addition, hybridization of the probe for a 63-base N1-terminal cassette of ethanol-sensitive NR1 splice variants labeled both cortex and hippocampus. The level of hybridization did not differ across subfields of the hippocampus. Results from Western blot and immunohistochemical experiments also indicated that there were no differences between selected lines in NMDA receptor subunit protein expression. However, there was a correlation between mRNA and protein expression in hippocampus and cortex for each NMDA receptor subunit that was examined. Conclusions: The data suggest that at the level of both mRNA and protein, NMDA receptor subunit and splice variant expression can be uncoupled from convulsion severity in mice that have been selectively bred for symptoms of ethanol Withdrawal.
Amanda J Roberts - One of the best experts on this subject based on the ideXlab platform.
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Genetic Differences in Behavioral Sensitivity to a Neuroactive Steroid
2020Co-Authors: Deborah A Finn, Amanda J Roberts, Frank Lotrich, Edward J GallaherAbstract:ABSTRACT Recent work found that lower endogenous levels of the ␥-aminobutyric acid-agonist, neuroactive steroid 3␣-hydroxy-5␣-pregnan-20-one (3␣,5␣-THP) may be correlated with increased ethanol Withdrawal severity in the selectively bred Withdrawal Seizure-Prone and -Resistant mice. The present studies were conducted to determine whether decreased sensitivity to 3␣,5␣-THP was correlated with ethanol Withdrawal hyperexcitability in another genetic mouse model, namely the C57BL/6 (B6) and DBA/2 (D2) inbred strains. These strains also differ in ethanol Withdrawal severity (D2 Ͼ Ͼ B6). B6 and D2 male mice were injected with 3␣,5␣-THP (0 -10 mg/kg i.p.) 15 min before the timed tail vein infusion of pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anticonvulsant effect of 3␣,5␣-THP. Subsequent studies measured sensitivity to several of the pharmacological effects of 3␣,5␣-THP. B6 and D2 male mice were injected with 3␣,5␣-THP (0 -32 mg/kg) before testing for locomotor activation (total number of entries) and anxiolysis (percent open arm entries) on the elevated plus maze, muscle relaxation (impairment of forelimb grip strength), ataxia (impairment of Rotarod performance) and Seizure susceptibility to pentylenetetrazol. B6 mice were more sensitive than D2 animals to the anxiolytic, locomotor stimulant and anticonvulsant effects of 3␣,5␣-THP. In contrast, D2 mice were more sensitive than B6 mice to 3␣,5␣-THP-induced muscle relaxation and ataxia. Plasma 3␣,5␣-THP levels did not differ in the B6 and D2 mice injected with this steroid, suggesting that the strain differences were not pharmacokinetic. Collectively, the results in selectively bred Withdrawal Seizure-Prone and -Resistant mice and B6 and D2 inbred strains suggest that genetic differences in neuroactive steroid sensitivity and biosynthesis may contribute to ethanol Withdrawal severity
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neuroactive steroid sensitivity in Withdrawal Seizure prone and resistant mice
Alcoholism: Clinical and Experimental Research, 1995Co-Authors: Deborah A Finn, Amanda J Roberts, John C. CrabbeAbstract:Withdrawal Seizure-Prone (WSP) and -Resistant (WSR) mice, which were selectively bred for severe (WSP) or mild (WSR) handling-induced convulsions (HICs) following chronic ethanol inhalation, were found to differ in sensitivity to the anticonvulsant effects of the neuroactive steroid 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha,5 alpha-P. 3 alpha,5 alpha-P (5 or 10 mg/kg, ip) significantly increased Seizure thresholds to pentylenetetrazol in ethanol-native males of both the WSP and WSR lines. In general, WSP mice were more sensitive than WSR mice to the anticonvulsant effect of 3 alpha,5 alpha-P. Subsequent studies in male WSP mice exposed to ethanol vapor or air for 24 hr demonstrated enhanced sensitivity to the anticonvulsant effect of 3 alpha,5 alpha-P (0.5-20 mg/kg, ip) during ethanol Withdrawal. Only the highest dose affected HICs in air-exposed animals, whereas both the two highest doses significantly reduced HICs in ethanol-exposed mice. These results provide the first demonstration that 3 alpha,5 alpha-P attenuates ethanol Withdrawal convulsions and indicate enhanced sensitivity to the anticonvulsant effect of 3 alpha,5 alpha-P in animals withdrawing from ethanol dependence.
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type i corticosteroid receptors modulate ptz induced convulsions of Withdrawal Seizure prone mice
Brain Research, 1993Co-Authors: John C. Crabbe, Amanda J Roberts, Donald L KeithAbstract:Corticosteroids have been shown to modulate convulsion expression in humans and animals. It is hypothesized that type I corticosteroid receptors mediate the excitatory effects of corticosteroids in vivo based on low-dose efficacy of corticosterone, and differential effects of mineralocorticoids vs. glucocorticoids on convulsions. In the present experiments, the effects of altering corticosterone levels, and the role of the type I receptor in mediating these effects, were examined using pentylenetetrazol (PTZ)-induced convulsions in ethanol Withdrawal Seizure prone (WSP) mice. It was hypothesized that stimulation of type I receptors partially mediates the expression of tonic hindlimb extensor (THE) convulsions produced by PTZ. Aminoglutethimide, a steroid synthesis inhibitor, increased latencies to PTZ-induced THE. This anticonvulsant effect was reversed by corticosterone and the type I agonist, deoxycorticosterone (DOC), but not by the type II agonist, dexamethasone. Furthermore, two type I receptor antagonists, spironolactone and RU26752, increased latencies to PTZ-induced THE, suggesting that they have anticonvulsant action. In summary, the results of these experiments suggest that type I corticosteroid receptors are important for expression of PTZ-induced convulsions.
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differential modulation by the stress axis of ethanol Withdrawal Seizure expression in wsp and wsr mice
Alcoholism: Clinical and Experimental Research, 1991Co-Authors: Amanda J Roberts, John C. Crabbe, H P Chu, L D KeithAbstract:Withdrawal from both acute and chronic ethanol (EtOH) exposure is associated with increased neural excitability and increased activity of the hypothalamic-pituitary-adrenal axis. There is some evidence that glucocorticoids are necessary for EtOH Withdrawal Seizure expression. Lines of mice that were selected for severe (WSP) and minimal (WSR) EtOH Withdrawal (as estimated from handling-induced convulsion scores) have been shown to differ in their stress response following an acute dose of EtOH. In this study we provide evidence that these lines of mice also differ in their sensitivity to the excitatory effects of glucocorticoids. EtOH Withdrawal Seizures of WSP mice were significantly increased by chronic and acute corticosterone treatment, whereas those of the WSR mice were unaffected. Neural excitability was decreased in the WSP mice when aminoglutethimide, a glucocorticoid synthesis blocker, was administered. Thus, it appears that genetic differences in EtOH Withdrawal Seizure severity may be due, in part, to differences in sensitivity to the excitatory effects of glucocorticoids.
