Vapor Inhalation of Alcohol in Rats

Abstract

Alcohol dependence constitutes a neuroadaptive state critical for understanding alcoholism, and various methods have been utilized to induce alcohol dependence in animals, one of which is alcohol vapor exposure. Alcohol vapor inhalation provides certain advantages over other chronic alcohol exposure procedures that share the ultimate goal of producing alcohol dependence in rats. Chronic alcohol vapor inhalation allows the experimenter to control the dose, duration, and pattern of alcohol exposure. Also, this procedure facilitates testing of somatic and motivational aspects of alcohol dependence. Chronic exposure to alcohol vapor produces increases in alcohol-drinking behavior, increases in anxiety-like behavior, and reward deficits in rats. Alcohol vapor inhalation as a laboratory protocol is flexible, and the parameters of this procedure can be adjusted to accommodate the specific aims of different experiments. This unit describes the options available to investigators using this procedure for dependence induction, when different options are more or less appropriate, and the implications of each.

Neuropeptide Receptors as Treatment Targets in Alcohol Use Disorders

“…These can involve passive induction of dependence (318) or IA to voluntary consumption of alcohol (286). Several studies have reported that previous experience with alcohol leads to higher initial levels of consumption and increased preference (315,319,320). This supports our finding that rats with previous experience with operant alcohol self-administration consumed more alcohol and had higher preference for alcohol compared with controls in the IA two-bottle free choice preference drinking model.…”

Alcohol inhalation

“…3 Chronic alcohol inhalation through continuous exposure in a vapour chamber was found to be the most effective way to induce alcohol dependence in rodents. 4 …”

Animal models of alcohol and drug dependence

“…Upon cessation of alcohol vapor exposure, animals exhibit signs of tolerance and physical dependence and may be tested for a multitude of motivational, acute withdrawal-and protracted abstinence-related behaviors. 21 Gilpin et al 15 exposed rats to alcohol vapor for 4 hours and measured alcohol concentration in brain dialysates and blood samples collected from the tail vein at 30-minute intervals during the 4-hour exposure, as well as 8 hours following termination of alcohol vapor exposure. They found that the maximum levels of alcohol attained in blood and brain during vapor exposure were 208615 mg/ dL and 215625 mg/dL respectively.…”

“…Previous studies using the chronic intermittent alcohol vapor model showed that motivational symptoms of dependence are present in rats at acute withdrawal time points, as evidenced by increased anxiety-like behavior, increased alcohol drinking, and increased willingness to work for alcohol early during acute withdrawal, even when animals still have alcohol in their blood from vapor exposure. [21][22][23][24][25] All animal models of alcohol dependence are, in fact, models of components of alcohol dependence.…”