Fellowship for Thomas Wooters: Reinforcing and Neurochemical Effects of Cocaine in a Rident Model of ADHD

No major changes have occurred since the prior application. B. PROGRESS I have completed TOX 600 "Research Ethics", a course which dealt with ethical issues in the conduct of both animal and human research, and have completed other laboratory training (i.e., hazardous materials, etc.). I have also continued to attend the Neuropharmacology Journal Club through the UK College of Pharmacy and the monthly Local NIDA ("Neuroscientists Interested in Drug Abuse") meetings. I am also scheduled to present a talk at the Local NIDA meeting in February 2009. Regarding research activity, I have been involved in several research projects since the submission of the last application. In addition to ongoing work dedicated to characterizing the behavioral effects of novel nAChR antagonists as potential smoking cessation medications, I have involved with supervising an undergraduate honor's thesis project comparing the effects of oral vs. intraperitonéal methylphenidate (10 mg/kg) in the locomotor activity and conditioned place preference procedures. While preliminary, our findings to date suggest that although the locomotor stimulant effect of oral methylphenidate is minor relative to intraperitoneal methylphenidate, rats express comparable methylphenidate-conditioned place preference for 10 mg/kg of methylphenidate given via either route. The next round of experiments will assess the parameteric (i.e., dose and PK parameters) aspects of the initial findings in further detail. I have also recently initiated another experiment comparing the effects of methylphenidate and other stimulant drugs on performance of an operant delay-discounting task in Sprague-Dawley (S-D), Spontaneously Hypertensive (SHR) and Wistar-Kyoto(WKY) rat strains; similar to the experiments outlined in the present application, those data should provide information regarding the viability of the SHR animal model of attention-deficit/hyperactivity disorder (ADHD). Regarding the NRSA project specifically, I have completed periadolescent treatment of SHR and S-D rats with oral methylphenidate. Results obtained thus far suggest that periadolescent SHR are hypersensitive to methylphenidate compared to S-D rats. The next phase of the project will determine whether these findings lead to alterations in the response to cocaine.