Format

Send to

Choose Destination
Alcohol. 2014 Dec;48(8):741-54. doi: 10.1016/j.alcohol.2014.07.015. Epub 2014 Oct 18.

Environmental stressors influence limited-access ethanol consumption by C57BL/6J mice in a sex-dependent manner.

Author information

1
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA.
2
Portland Alcohol Research Center, Department of Veterans Affairs Medical Research, Portland, OR 97239, USA.
3
Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, USA; Portland Alcohol Research Center, Department of Veterans Affairs Medical Research, Portland, OR 97239, USA. Electronic address: finnd@ohsu.edu.

Abstract

Exposure to stress contributes to ethanol consumption in humans, but it produces inconsistent effects on ethanol drinking in rodent models. Therefore, the present study examined the influence of different stressors (restraint, tail suspension, predator odor, foot shock, and tail pinch) on 2-h access to water and 10% ethanol by male and female C57BL/6J mice and determined whether there were sex-dependent differences in response to stress. Plasma corticosterone (CORT) and allopregnanolone (ALLO) were assessed as indexes of hypothalamic-pituitary-adrenal axis activity and of endogenous neurosteroid levels, respectively, following restraint, tail suspension, and predator odor. These stressors increased plasma CORT and ALLO levels, and produced a greater increase in CORT and ALLO levels in females versus males. Ethanol intake was decreased following restraint, tail suspension, foot shock, and tail pinch in both sexes, with stressor-related differences in the duration of the suppression. Predator odor significantly increased ethanol intake on the following two days in females and on the second day after stress in males. Notably, there was a significant positive correlation between CORT levels immediately after predator odor stress and ethanol intake on the following day. In summary, the type of stressor influenced ethanol consumption, with subtle sex differences in the magnitude and persistence of the effect. These findings are the first to demonstrate that a single, acute exposure to restraint, tail suspension, and predator odor stress increased plasma CORT and ALLO levels in animals with a history of ethanol consumption and that female mice were more responsive than males to the ability of stress to increase CORT and ALLO levels as well as to increase ethanol intake following predator odor stress. Because predator odor stress is a model of post-traumatic stress disorder (PTSD), the present sex differences have important implications for preclinical studies modeling the comorbidity of PTSD and alcohol use disorders.

KEYWORDS:

Allopregnanolone; Corticosterone; Environmental stress; Foot shock; Predator odor; Tail pinch

PMID:
25459519
PMCID:
PMC4371601
DOI:
10.1016/j.alcohol.2014.07.015
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center