RESUMEN
Genetic aspects of alcoholism have been modeled using rats selectively bred for extremes of alcohol preference and voluntary alcohol intake. These lines show similar alcohol drinking phenotypes but have different genetic and environmental backgrounds and may therefore display diverse behavioral traits as seen in human alcoholics. The multivariate concentric square field™ (MCSF) test is designed to provoke exploration and behaviors associated with risk assessment, risk taking and shelter seeking in a novel environment. The aim was to use the MCSF to characterize behavioral profiles in rat lines from selective breeding programs in the United States (P/NP, HAD1/LAD1, HAD2/LAD2), Italy (sP/sNP) and Finland (AA/ANA). The open field and elevated plus maze tests were used as reference tests. There were substantial differences within some of the pairs of selectively bred rat lines as well as between all alcohol-preferring rats. The most pronounced differences within the pairs of lines were between AA and ANA rats and between sP and sNP rats followed by intermediate differences between P and NP rats and minor differences comparing HAD and LAD rats. Among all preferring lines, P, HAD1 and HAD2 rats shared similar behavioral profiles, while AA and sP rats were quite different from each other and the others. No single trait appeared to form a common 'pathway' associated with a high alcohol drinking phenotype among all of the alcohol-preferring lines of rats. The marked behavioral differences found in the different alcohol-preferring lines may mimic the heterogeneity observed among human alcoholic subtypes.
Asunto(s)
Consumo de Bebidas Alcohólicas/genética , Consumo de Bebidas Alcohólicas/psicología , Alcoholismo/genética , Alcoholismo/psicología , Conducta Animal , Pruebas Neuropsicológicas/estadística & datos numéricos , Alcoholismo/complicaciones , Animales , Ansiedad/complicaciones , Ansiedad/genética , Ansiedad/psicología , Conducta de Elección , Modelos Animales de Enfermedad , Conducta Exploratoria , Conducta Impulsiva/complicaciones , Conducta Impulsiva/genética , Conducta Impulsiva/psicología , Masculino , Aprendizaje por Laberinto , Ratas , Ratas Wistar , Asunción de Riesgos , Especificidad de la Especie , Estadísticas no ParamétricasRESUMEN
RATIONALE: Swim test susceptible (SUS) rats selectively bred for reduced struggling in the forced swim test (FST) following stress show high voluntary ethanol intake like alcohol-preferring (P) rats selectively bred for ethanol preference. It is unknown whether stress enhances drinking in SUS rats or FST behavior in P and non-preferring (NP) rats. OBJECTIVES: The aim of this study was to assess the response to stress in male SUS, Sprague-Dawley (SD), P, and NP rats on 10% ethanol drinking and FST behavior. METHODS: In experiment 1, SUS and SD rats had limited access to ethanol and water following white noise, rehousing, and forced swim stress. In experiment 2, P and NP rats received footshock, white noise, restraint, or no stress prior to the FST. Rats then had continuous access to ethanol and water, and the effects of weekly exposures to stress were measured. RESULTS: SUS rats drank more ethanol (M = 2.98 g/kg) than SD rats (M = 1.26 g/kg) at baseline. Stress produced sustained increases (~33% of baseline) in ethanol intake in SUS rats. NP rats spent twice as much time immobile as P rats in the FST. Stress did not alter FST behavior in P or NP rats. Only footshock produced an increase (~29%) in ethanol intake in P rats. CONCLUSIONS: Selection for stress-induced depressive-like behavior in SUS rats is associated with enhanced stress-induced ethanol drinking. However, the selection for alcohol preference is not associated with stress-induced depressive-like behavior but is associated with footshock stress-induced ethanol drinking. In these experiments, relationships among stress, depressive-like behavior, and alcohol preference were not symmetrical.