My main interests lie in the contribution of genetic differences to the varying reactivity animals have in their behavioral responses to administration of drugs of abuse. Genetic differences in the behavioral responses elicited by drugs of abuse could provide important information about inherent vulnerabilities animals might have to develop patterns of drug-addictive behavior. These differences can also provide information as to the role genes play in controlling the systems that respond to drugs of abuse. Moreover, these inherent vulnerabilities could affect the overall acceptability of the drug, with differences emerging in the animal's positive (rewarding/reinforcing) or negative (aversion) affective responses to drug intake. In this regard, I use genetically distinct inbred strains of rats (Fischer and Lewis animals), that differ in their affective responses to drug administration, to investigate the contribution of inherent differences in drug-related behaviors. These strains differ in their responses to many drugs, including cocaine, morphine and other opiates. My main goal is to investigate the inherent differences in opioid reactivity in these strains, and use this knowledge to help understand the genetic mediation of the differential sensitivity to opiate administration.

PUBLICATIONS
Journal Articles and Proceedings
1. Roma PG, Davis CM, Riley AL. Effects of cross-fostering on cocaine-induced taste aversions in Fischer and Lewis rats. Dev Psychobiol 2007;49(2):172-9.
2. Davis CM, Riley AL. The effects of cocaine preexposure on cocaine-induced conditioned taste aversion learning in Fischer and Lewis rat strains. Pharmacol Biochem Behav 2007;87(1):198-200.
3. Davis CM, Roma PG, Dominguez JM, Riley AL. Morphine-induced place conditioning in Fischer and Lewis rats: acquisition and dose-response in a fully biased procedure. Pharmacol Biochem Behav 2007;86(3):516-23.
4. Riley AL, Davis CM, Roma PG. (in press) Strain differences in taste aversion learning: Implications for animal models of drug abuse. In: Reilly, S. & Schachtman, T.D., editors. Conditioned taste aversion: Behavioral and neural processes. New York: Academic Press.
5. Roma PG, Davis CM, Huntsberry ME, Kohut SJ, Riley AL. (submitted) Early maternal separation and sex differences in the aversive and motor-stimulating effects of amphetamine in adult rats.
6. Fox MA, Davis CM, Lipizzi EL, Monks CA, Riley AL. (submitted) The effects of mu, delta and kappa opioid receptor antagonists on the acquisition of morphine-induced taste aversions.

CONFERENCE PRESENTATIONS
Poster Presentations
1. Davis, C.M. & Sawchuk, A. (2004, March). Biochemical and immunofluorescence evidence of NMDA receptor subunits in Ambystoma tigrinum retina. Western Pennsylvania Undergraduate Biology Symposium, Pittsburgh, PA.
2. Davis, C.M., Roma, P.G., Keeler, M.A. & Riley, A.L. (2005, June). Genetic strain, maternal environment, and biological sex interact to affect cocaine-induced taste aversions in the Fischer and Lewis rats. College on Problems of Drug Dependence, Orlando, FL. [Full Text]
3. Davis, C.M., Roma, P.G. & Riley, A.L. (2005, August). Cross-fostering effects on the extinction of cocaine-induced taste aversions in the Fischer and Lewis rat strains. American Psychological Association, Washington, DC. [Full Text]
4. Davis, C.M., Valderama, J. & Riley, A.L. (2005, November). Effects of morphine preexposure on morphine-induced taste aversions and place preferences in the Fischer (F344) and Lewis (LEW) inbred rat strains. Society for Neuroscience, Washington, DC. [Full Text]
5. Davis, C.M. & Riley, A.L. (2006, June). Effects of drug preexposure on place preferences and taste aversions in Fischer (F344) and Lewis (LEW) rats. College on Problems of Drug Dependence, Scottsdale, AZ. [Full Text]
6. Roma, P.G., Davis, C.M. & Riley, A.L. (2006, June). Acquisition of drug-induced conditioned place preferences in Fischer and Lewis rats. College on Problems of Drug Dependence, Scottsdale, AZ.
7. Davis CM, Rice KC, Riley AL. (2007, June) Strain differences in (-)-U50,488H-induced conditioned taste aversions. Poster presented at the annual meeting of the College on Problems of Drug Dependence, Quebec City, Quebec, Canada.
Invited Talks
1. Riley A, Davis C, Roma P. Epigenetic factors in drug use and abuse. Invited presentation at University of Granada (Granada, Spain), 2007.
2. Riley A, Davis C, Roma P. Epigenetic factors in drug use and abuse. Invited presentation at Universitat Rovira I Virgili (Reus, Spain), 2007.
3. Riley A, Davis C, Roma P. Epigenetic factors in drug use and abuse. Invited presentation at University of Guelph (Guelph, Ontario, Canada), 2007.