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Radcliffe RA, Erwin VG, Bludeau P, Deng X, Fay T, Floyd KL, Deitrich RA. A major QTL for acute ethanol sensitivity in the alcohol tolerant and non-tolerant selected rat lines. GENES BRAIN AND BEHAVIOR 2009; 8:611-25. [PMID: 19500156 DOI: 10.1111/j.1601-183x.2009.00496.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The Alcohol Tolerant and Alcohol Non-Tolerant rats (AT, ANT) were selectively bred for ethanol-induced ataxia as measured on the inclined plane. Here we report on a quantitative trait locus (QTL) study in an F(2) intercross population derived from inbred AT and ANT (IAT, IANT) and a follow-up study of congenics that were bred to examine one of the mapped QTLs. Over 1200 F(2) offspring were tested for inclined plane sensitivity, acute tolerance on the inclined plane, duration of the loss of righting reflex (LORR) and blood ethanol at regain of the righting reflex (BECRR). F(2) rats that were in the upper and lower 20% for inclined plane sensitivity were genotyped with 78 SSLP markers. Significant QTLs for inclined plane sensitivity were mapped on chromosomes 8 and 20; suggestive QTLs were mapped on chromosomes 1, 2 and 3. Highly significant QTLs for LORR duration (LOD = 12.4) and BECRR (LOD = 5.7) were mapped to the same locus on chromosome 1. Breeding and testing of reciprocal congenic lines confirmed the chromosome 1 LORR/BECRR QTL. A series of recombinant congenic sub-lines were bred to fine-map this QTL. Current results have narrowed the QTL to an interval of between 5 and 20 Mb. We expect to be able to narrow the interval to less than 5 Mb with additional genotyping and continued breeding of recombinant sub-congenic lines.
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Affiliation(s)
- R A Radcliffe
- Department of Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO 80045, USA.
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2
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Warnault V, Houchi H, Barbier E, Pierrefiche O, Vilpoux C, Ledent C, Daoust M, Naassila M. The lack of CB1 receptors prevents neuroadapatations of both NMDA and GABA(A) receptors after chronic ethanol exposure. J Neurochem 2007; 102:741-52. [PMID: 17442049 DOI: 10.1111/j.1471-4159.2007.04577.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
As the contribution of cannabinoid (CB1) receptors in the neuroadaptations following chronic alcohol exposure is unknown, we investigated the neuroadaptations induced by chronic alcohol exposure on both NMDA and GABA(A) receptors in CB1-/- mice. Our results show that basal levels of hippocampal [(3)H]MK-801 ((1)-5-methyl-10,11-dihydro-5Hdibenzo[a,d]cyclohepten-5,10-imine) binding sites were decreased in CB1-/- mice and that these mice were also less sensitive to the locomotor effects of MK-801. Basal level of both hippocampal and cerebellar [(3)H]muscimol binding was lower and sensitivity to the hypothermic effects of diazepam and pentobarbital was increased in CB1-/- mice. GABA(A)alpha1, beta2, and gamma2 and NMDA receptor (NR) 1 and 2B subunit mRNA levels were altered in striatum of CB1-/- mice. Our results also showed that [(3)H]MK-801 binding sites were increased in cerebral cortex and hippocampus after chronic ethanol ingestion only in wild-type mice. Chronic ethanol ingestion did not modify the sensitivity to the locomotor effects of MK-801 in both genotypes. Similarly, chronic ethanol ingestion reduced the number of [(3)H]muscimol binding sites in cerebral cortex, but not in cerebellum, only in CB1+/+ mice. We conclude that lifelong deletion of CB1 receptors impairs neuroadaptations of both NMDA and GABA(A) receptors after chronic ethanol exposure and that the endocannabinoid/CB1 receptor system is involved in alcohol dependence.
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MESH Headings
- Adaptation, Physiological/genetics
- Alcohol-Induced Disorders, Nervous System/genetics
- Alcohol-Induced Disorders, Nervous System/metabolism
- Alcohol-Induced Disorders, Nervous System/physiopathology
- Alcoholism/genetics
- Alcoholism/metabolism
- Alcoholism/physiopathology
- Animals
- Binding Sites/drug effects
- Binding Sites/physiology
- Binding, Competitive/drug effects
- Binding, Competitive/physiology
- Brain/drug effects
- Brain/metabolism
- Brain/physiopathology
- Brain Chemistry/drug effects
- Brain Chemistry/genetics
- Chronic Disease
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Ethanol/adverse effects
- Excitatory Amino Acid Antagonists/pharmacology
- GABA Agonists/pharmacology
- Male
- Mice
- Mice, Knockout
- Muscimol/metabolism
- Protein Subunits/genetics
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/genetics
- Receptors, GABA-A/drug effects
- Receptors, GABA-A/metabolism
- Receptors, N-Methyl-D-Aspartate/drug effects
- Receptors, N-Methyl-D-Aspartate/metabolism
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Affiliation(s)
- Vincent Warnault
- Equipe Région INSERM 24 (ERI24), Groupe de Recherche sur l'Alcool et les Pharmacodépendances, Université de Picardie Jules Verne, Faculté de Pharmacie, Amiens, France, and IFR 114, Lille, France
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3
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Haugbøl SR, Ebert B, Ulrichsen J. UPREGULATION OF GLUTAMATE RECEPTOR SUBTYPES DURING ALCOHOL WITHDRAWAL IN RATS. Alcohol Alcohol 2004; 40:89-95. [PMID: 15569719 DOI: 10.1093/alcalc/agh117] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS To investigate glutamate receptor subtypes during alcohol withdrawal. METHODS Rats were exposed to severe alcohol intoxication for 84 h and then decapitated at 0, 12 and 36 h after the last alcohol dose (n = 7 per group). Alcohol was administered five times a day by intragastric intubation. The densities of N-methyl-D-aspartate (NMDA) and 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors were studied in membranes from the forebrain by using the specific ligands [3H]MK-801 and [3H]AMPA, respectively. RESULTS Although no change in the maximal density (B(max)) of [3H]MK-801 binding sites was observed at the time of withdrawal, [3H]MK-801 binding was increased by 49% 12 h into the withdrawal reaction compared with the control group. At 36 h post alcohol the B(max) of the [3H]MK-801 binding was still increased by 24% compared with the control group; however, this difference was not statistically significant. When investigated at the time of withdrawal from chronic alcohol intoxication, no significant alterations in the B(max) of the [3H]AMPA binding was detected, but 12 h into the withdrawal reaction the [3H]AMPA binding was markedly increased by 94%. At 36 h post alcohol the [3H]AMPA binding had returned to control levels. No significant alterations in the dissociation constant (K(D)) of either [3H]MK-801 or [3H]AMPA binding was observed at any time point. CONCLUSIONS NMDA and AMPA receptors are involved in the cerebral hyperactivity of alcohol withdrawal.
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Vekovischeva OY, Aitta-Aho T, Echenko O, Kankaanpää A, Seppälä T, Honkanen A, Sprengel R, Korpi ER. Reduced aggression in AMPA-type glutamate receptor GluR-A subunit-deficient mice. GENES BRAIN AND BEHAVIOR 2004; 3:253-65. [PMID: 15344919 DOI: 10.1111/j.1601-1848.2004.00075.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The importance of AMPA-type glutamate receptors has been demonstrated in neuronal plasticity and in adaptation to drugs of abuse. We studied the involvement of AMPA receptors in social interaction and anxiety and found that in several paradigms of agonistic behavior naïve male mice deficient for the GluR-A subunit- containing AMPA receptors are less aggressive than wild-type littermates. GluR-A deficient mice and wild-type littermates exhibited similar basic behavior and reflexes as monitored by observational Irwin's test, but they tended to be less anxious in elevated plus-maze and light-dark tests. Maternal aggression or male-female encounters were not affected which suggests that male hormones are involved in the expression of suppressed aggressiveness. However, testosterone levels and brain monoamines can be excluded and found to be similar between GluR-A deficient and wild-type littermates. The reduced AMPA receptor levels caused by the lack of the GluR-A subunit, and measured by a 30% reduction in hippocampal [3H]-S-AMPA binding, seem to be the reason for suppressed male aggressiveness. When we analyzed mice with reduced number of functional AMPA receptors mediated by the genomic introduced GluR-A(Q582R) channel mutation, we observed again male-specific suppressed aggression, providing additional evidence for GluR-A subunit-containing AMPA receptor involvement in aggression.
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Affiliation(s)
- O Y Vekovischeva
- Institute of Biomedicine/Pharmacology, Biomedicum Helsinki, University of Helsinki, Finland
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5
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Devaud LL, Bartoo G, Malthankar G. Altered responses to dizocilpine maleate administration in ethanol-withdrawn male and female rats. Alcohol 2002; 28:83-93. [PMID: 12457939 DOI: 10.1016/s0741-8329(02)00239-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dizocilpine maleate (MK-801) is a highly potent, noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. Although it has been suggested that dizocilpine may be beneficial in alleviating some symptoms of ethanol withdrawal, a rigorous evaluation of beneficial versus detrimental (phencyclidine-like) actions has not been done. The objective of the present investigation was to explore whether dizocilpine protects against ethanol withdrawal-induced increases in seizure susceptibility without being compromised by its phencyclidine-like behavioral actions. The effects of dizocilpine were assessed by using seizure threshold determinations and scoring of open field behaviors. Low dose dizocilpine administration preferentially protected against bicuculline seizure induction in ethanol-withdrawn female rats when compared with findings in ethanol-withdrawn male rats. In contrast, we found dramatic reductions in dizocilpine-induced open field behaviors during ethanol withdrawal in both male and female rats compared with findings for pair-fed control animals. [3H]MK-801 binding analysis ruled out changes in cerebral cortex or hippocampus receptor density or affinity as having a primary role in these differential responses. Taken together, our findings from these studies indicate that there are complex neuroadaptations in NMDA receptor systems after persistent ethanol exposure, manifested as either enhanced or reduced responses, depending on the measure used.
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Affiliation(s)
- Leslie L Devaud
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, CB 8334, Pocatello, ID 83209-8334, USA.
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6
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Vekovischeva OY, Haapalinna A, Näkki R, Sarviharju M, Honkanen A, Heikkilä J, Korpi ER. Enhanced locomotor stimulation by NMDA receptor antagonists in alcohol-sensitive ANT rats. Pharmacol Biochem Behav 2000; 67:793-9. [PMID: 11166070 DOI: 10.1016/s0091-3057(00)00424-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ability of the antagonists for the N-methyl-D-aspartate (NMDA) type of glutamate receptor to modulate locomotor activity were compared in alcohol-sensitive (or alcohol-nontolerant, ANT) and alcohol-insensitive (or alcohol-tolerant, AT) rat lines. Both rat lines showed altered locomotor activity after acute injections of a competitive antagonist (LY235959), a glycine-site antagonist (L-701,324), or noncompetitive antagonists [MK-801, phencyclidine (PCP), and ketamine] of the NMDA receptor. MK-801 at 0.5 mg/kg caused a strong increase in horizontal activity in both rat lines, the effect being significantly greater in the ANT rats. There was a subpopulation among AT rats that was almost completely unresponsive to MK-801. This insensitivity to MK-801 correlated with the lack of c-fos induction in the retrosplenial and cingulate cortices. Fos immunoreactive cells in these brain regions after MK-801 treatment were more numerous in ANT than AT rats, although c-fos induction in the inferior olivary nucleus was similar in all animals after MK-801. The ANT rats showed greater locomotor stimulation also after ketamine and LY235959, while stimulation induced by PCP and depression induced by L-701,324 did not differ between the rat lines. The data suggest that altered NMDA receptor-mediated processes may correlate with differences in innate alcohol sensitivity in the ANT/AT rat model.
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Affiliation(s)
- O Y Vekovischeva
- Department of Pharmacology and Clinical Pharmacology, University of Turku, FIN-20520 Turku, Finland
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Dodd PR, Beckmann AM, Davidson MS, Wilce PA. Glutamate-mediated transmission, alcohol, and alcoholism. Neurochem Int 2000; 37:509-33. [PMID: 10871702 DOI: 10.1016/s0197-0186(00)00061-9] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Glutamate-mediated neurotransmission may be involved in the range of adaptive changes in brain which occur after ethanol administration in laboratory animals, and in chronic alcoholism in human cases. Excitatory amino acid transmission is modulated by a complex system of receptors and other effectors, the efficacy of which can be profoundly affected by altered gene or protein expression. Local variations in receptor composition may underlie intrinsic regional variations in susceptibility to pathological change. Equally, ethanol use and abuse may bring about alterations in receptor subunit expression as the essence of the adaptive response. Such considerations may underlie the regional localization characteristic of the pathogenesis of alcoholic brain damage, or they may form part of the homeostatic change that constitutes the neural substrate for alcohol dependence.
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Affiliation(s)
- P R Dodd
- Department of Biochemistry, University of Queensland, Qld 4072, Brisbane, Australia.
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Velardo MJ, Simpson VJ, Zahniser NR. Differences in NMDA Receptor Antagonist-Induced Locomotor Activity and [3H]MK-801 Binding Sites in Short-Sleep and Long-Sleep Mice. Alcohol Clin Exp Res 1998. [DOI: 10.1111/j.1530-0277.1998.tb03943.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Faingold CL, N'Gouemo P, Riaz A. Ethanol and neurotransmitter interactions--from molecular to integrative effects. Prog Neurobiol 1998; 55:509-35. [PMID: 9670216 DOI: 10.1016/s0301-0082(98)00027-6] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
There is extensive evidence that ethanol interacts with a variety of neurotransmitters. Considerable research indicates that the major actions of ethanol involve enhancement of the effects of gamma-aminobutyric acid (GABA) at GABAA receptors and blockade of the NMDA subtype of excitatory amino acid (EAA) receptor. Ethanol increases GABAA receptor-mediated inhibition, but this does not occur in all brain regions, all cell types in the same region, nor at all GABAA receptor sites on the same neuron, nor across species in the same brain region. The molecular basis for the selectivity of the action of ethanol on GaBAA receptors has been proposed to involve a combination of benzodiazepine subtype, beta 2 subunit, and a splice variant of the gamma 2 subunit, but substantial controversy on this issue currently remains. Chronic ethanol administration results in tolerance, dependence, and an ethanol withdrawal (ETX) syndrome, which are mediated, in part, by desensitization and/or down-regulation of GABAA receptors. This decrease in ethanol action may involve changes in subunit expression in selected brain areas, but these data are complex and somewhat contradictory at present. The sensitivity of NMDA receptors to ethanol block is proposed to involve the NMDAR2B subunit in certain brain regions, but this subunit does not appear to be the sole determinant of this interaction. Tolerance to ethanol results in enhanced EAA neurotransmission and NMDA receptor upregulation, which appears to involve selective increases in NMDAR2B subunit levels and other molecular changes in specific brain loci. During ETX a variety of symptoms are seen, including susceptibility to seizures. In rodents these seizures are readily triggered by sound (audiogenic seizures). The neuronal network required for these seizures is contained primarily in certain brain stem structures. Specific nuclei appear to play a hierarchical role in generating each stereotypical behavioral phases of the convulsion. Thus, the inferior colliculus acts to initiate these seizures, and a decrease in effectiveness of GABA-mediated inhibition in these neurons is a major initiation mechanism. The deep layers of superior colliculus are implicated in generation of the wild running behavior. The pontine reticular formation, substantia nigra and periaqueductal gray are implicated in generation of the tonic-clonic seizure behavior. The mechanisms involved in the recruitment of neurons within each network nucleus into the seizure circuit have been proposed to require activation of a critical mass of neurons. Achievement of critical mass may involve excess EAA-mediated synaptic neurotransmission due, in part, to upregulation as well as other phenomena, including volume (non-synaptic diffusion) neurotransmission. Effects of ETX on receptors observed in vitro may undergo amplification in vivo to allow the excess EAA action to be magnified sufficiently to produce synchronization of neuronal firing, allowing participation of the nucleus in seizure generation. GABA-mediated inhibition, which normally acts to limit excitation, is diminished in effectiveness during ETX, and further intensifies this excitation.
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Affiliation(s)
- C L Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, Springfield 62794-1222, USA
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Toropainen M, Nakki R, Honkanen A, Rosenberg PH, Laurie DJ, Pelto-Huikko M, Koistinaho J, Eriksson CJP, Korpi ER. Behavioral Sensitivity and Ethanol Potentiation of the N-Methyl-d-Aspartate Receptor Antagonist MK-801 in a Rat Line Selected for High Ethanol Sensitivity. Alcohol Clin Exp Res 1997. [DOI: 10.1111/j.1530-0277.1997.tb03820.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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