Semester
Summer
Date of Graduation
2023
Document Type
Dissertation
Degree Type
PhD
College
Eberly College of Arts and Sciences
Department
Psychology
Committee Chair
Karen G. Anderson
Committee Member
Kathryn Kestner
Committee Member
Melissa Blank
Committee Member
Mariya Cherkasova
Committee Member
Tim Nurkiewicz
Abstract
Ethanol (EtOH) and nicotine (NIC) are among the most commonly used and co-used drugs in the world. Co-use occurs in people who use one or both drugs chronically, but also in people who only consume one or both drugs acutely, often in a “bingeing and chipping” pattern. Given that each drug on its own has previously been shown to affect impulsive choice in delay-discounting procedures, with some indication that drug effects could vary by sex, the purpose of the present experiments was to investigate effects of combined EtOH and NIC at a range of dose combinations on delay discounting in male and female Sprague-Dawley rats. Eight rats of each sex (n = 16) were trained on a two-lever delay-discounting procedure until choice for the larger, delayed reinforcer was stable. In Experiment 1, EtOH alone (0-3.0 g/kg; p.o.) was tested; in Experiment 2, NIC alone (0-1.0 mg/kg; s.c.) and combined EtOH and NIC were tested. In both experiments, mixed ANOVAs were conducted to assess effects of sex, drug dose, session block, and delay series on choice for the larger reinforcer. Combination indices were calculated to assess the nature of combined drug effects. No significant sex differences were observed at baseline or following drug administration, but four female rats were on a shortened delay series. EtOH alone (2 and 3 g/kg) and NIC alone (0.3 mg/kg) both reduced choice for the larger reinforcer (i.e., increased impulsive choice) relative to vehicle. When the drugs were combined, percent choice for the larger reinforcer was reduced relative to vehicle. In general, combinations of the two drugs reduced choice for the larger reinforcer relative to each drug alone. Combination indices indicated that EtOH and NIC together exerted an antagonistic effect, with the combined effect less than the sum of its parts. Future directions include administering EtOH intragastrically, reversing the order of drug administration, and increasing the sample size to allow for variation in baseline discounting rates.
Recommended Citation
Chalme, Rebecca Lillian, "Effects of Combined Ethanol and Nicotine Administration on Delay Discounting in Male and Female Sprague-Dawley Rats" (2023). Graduate Theses, Dissertations, and Problem Reports. 12154.
https://researchrepository.wvu.edu/etd/12154
Embargo Reason
Publication Pending
Included in
Behavior and Behavior Mechanisms Commons, Experimental Analysis of Behavior Commons, Pharmacology Commons