title: Anxiety-like behaviors at the end of the nocturnal period in sP rats with a "history" of unpredictable, limited access to alcohol.
abstract: Recent research found that exposure of selectively bred, Sardinian alcohol-preferring (sP) rats to multiple alcohol concentrations (10%, 20%, and 30%, v/v), under the 4-bottle "alcohol vs. water" choice regimen, in daily 1-h drinking sessions with an unpredictable time schedule, promoted high intakes of alcohol (≥2 g/kg) when the drinking session occurred over the final hours of the dark phase of the light/dark cycle. The present study investigated whether these high intakes of alcohol (a) were associated with alterations in rats' emotional state (Experiment 1) and (b) were pharmacologically manipulable (Experiment 2). In both experiments, over a period of 12 days, sP rats were initially exposed daily to a 1-h drinking session during the dark phase; time of alcohol exposure was changed each day and was unpredictable to rats. The day after this 12-day drinking phase, rats were (a) exposed to the Social Interaction (SI) test at the 1st or 12th hour of the dark phase with no alcohol available (Experiment 1) or (b) treated with the positive allosteric modulator of the GABAB receptor, GS39783 (0, 25, 50, and 100 mg/kg, intragastrically [i.g.]), and exposed to a drinking session at the 12th hour of the dark phase (Experiment 2). In Experiment 1, rats exposed to the SI test during the 12th hour spent approximately 35% less time in "social" behaviors than rats exposed to the SI test during the 1st hour. No difference in "social" behaviors was observed between alcohol-naive sP rats exposed to the SI test at the 1st and 12th hour. In Experiment 2, all doses of GS39783 selectively reduced alcohol intake. These results suggest that (a) expectation of alcohol availability likely exacerbated the anxiety-like state of sP rats and (b) the GABAB receptor is part of the neural substrate underlying these exceptionally high intakes of alcohol in sP rats.
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy. Electronic address: colomb@unica.it.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Colombo
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Lobina
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Maccioni
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Mauro A M
authors.initials: MA
authors.lastname: Carai
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Lorrai
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy; Department of Biomedical Sciences, University of Cagliari, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Zaru
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Via Muroni 23, I-07100 Sassari, SS, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Contini
authors.affiliation: Department of Biotechnologies, Chemistry, and Pharmacy, University of Siena, Via Aldo Moro 2, I-53100 Siena, SI, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Mugnaini
authors.affiliation: Department of Biotechnologies, Chemistry, and Pharmacy, University of Siena, Via Aldo Moro 2, I-53100 Siena, SI, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Corelli
authors.affiliation: Neuroscience Institute, Section of Cagliari, National Research Council of Italy, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy; Department of Biomedical Sciences, University of Cagliari, S.S. 554, km. 4,500, I-09042 Monserrato, CA, Italy.
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Gessa
mesh_terms: D000428:Alcohol Drinking / Q000523:psychology; D000437:Alcoholism / Q000523:psychology*; D000818:Animals; D001007:Anxiety / Q000523:psychology*; D002492:Central Nervous System Depressants / Q000494:pharmacology*; D003517:Cyclopentanes / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology*; D018757:GABA Modulators / Q000494:pharmacology; D007398:Interpersonal Relations; D008297:Male; D011743:Pyrimidines / Q000494:pharmacology; D051381:Rats; D018080:Receptors, GABA-B / Q000187:drug effects; D012646:Self Administration; D012919:Social Behavior
chemical_list: D002492:Central Nervous System Depressants; D003517:Cyclopentanes; D018757:GABA Modulators; C478058:N,N'-dicyclopentyl-2-methylsulfanyl-5-nitro-pyrimidine-4,6-diamine; D011743:Pyrimidines; D018080:Receptors, GABA-B; D000431:Ethanol
keywords: Anxiety-like behaviors; Experimental model of binge drinking; Limited and unpredictable access to alcohol; Positive allosteric modulator of the GABA(B) receptor, GS39783; Sardinian alcohol-preferring (sP) rats; Time schedule of alcohol drinking