Investigation of genetic differences in the influence of ethanol on trace fear conditioning behavior in mice

Open Access
- Author:
- Henry, Emily
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Thomas J Gould, Thesis Supervisor
Charles T Anderson, Thesis Honors Advisor - Keywords:
- ethanol
alcohol
trace fear conditioning
inbred mice - Abstract:
- The genetic differences between individuals are important to consider when examining the effects of drugs on learning and memory. The neural circuitry of learning and memory can be affected by a number of different drugs, including alcohol. One way to study the effects of alcohol exposure on changes in learning is to use the Pavlovian model of fear conditioning. Trace fear conditioning is a type of fear conditioning in which there is a delay between the conditioned stimulus and the unconditioned stimulus, engaging regions of the brain that can be affected by alcohol. Inbred mouse strains are a useful animal model for this type of experiment due to their lack of genetic variability within strains. Genetic differences between strains, however, are of interest in this experiment because they may lead to unique responses to the fear conditioning paradigm in the presence of alcohol. The purpose of this honors thesis is to explore genetic differences in the effects of acute ethanol intoxication on the learning response to trace fear conditioning. These differences are important to investigate when considering how genetics play a role in how alcohol causes different learning deficits between individuals. The initial hypothesis was that there would be a significant effect of both strain and drug treatment on freezing, the learning response. Male and female C57BL/6J and DBA/2J mice were treated with saline or one of two doses of ethanol and tested through a trace fear conditioning program. The results of this experiment showed that ethanol contributed to inhibited fear learning in both context and cued tests. Strain was also found to have differing effects on ethanol sensitivity between C57BL/6J and DBA/2J mice. There were no significant effects of sex. These results suggest the potential for future research and have important implications for how genetics can influence the sensitivity of learning and memory mechanisms to alcohol.