Doctoral Candidate

I am currently working on my dissertation research that involves investigating methylphenidate (Ritalin) and a phenomenon known as behavioral sensitization. Little is known of the long-term behavioral and neurophysiological effects of methylphenidate in children and adults who have been chronically treated with the drug; and little is also known about the effects of methylphenidate treatment in early life with its possible cross-sensitization with addictive stimulants taken at a later age.

In my dissertation research, I am studying the roles that developmental, sex, and genetic factors play on methylphenidate-induced sensitization by determining (a) whether early exposure to methylphenidate in female and male juvenile rats increases their sensitivity to the drug when they are adult rats, (b) whether there are sex differences in the response to methylphenidate, and (c) whether treatment with methylphenidate in female and male juvenile and adult rats produces cross-sensitization to amphetamine. The study consists of (1) monitoring the locomotor activity of three genetically different strains of female and male rats (a model of ADHD, its control, and a model commonly used in drug studies involving stimulants) before and after acute and repeated methylphenidate administration when these rats are young and as adults followed by an amphetamine treatment and (2) evaluating sensory evoked potentials (brain activity responses) before and after drug treatment in brain areas believed to be involved with ADHD, behavioral sensitization, and cross-sensitization from freely behaving rats previously implanted with permanent electrodes.

Fellowships

• 2000-2002: National Institutes of Health Predoctoral (Institutional) Fellowship Training in Neuroscience
• 2002-Present: National Institutes of Health Predoctoral (Individual) National Research Service Awards (NRSA) Fellowship

Publications

• Gaytan, O., Yang, P. , Swann, A., Dafny, N. Diurnal differences in sensitization to methylphenidate, Brain Res earch 2000; 864: 24-39.
• Yang, P. , Swann, A., Dafny, N. NMDA receptor antagonist disrupts acute and chronic effects of methylphenidate, Physiology & Behavior 2000; 71: 133-145.
• Yang, P. , Beasley, A., Swann, A., Dafny, N. Valproate modulates the expression of methylphenidate (Ritalin) sensitization, Brain Research 2000; 874: 216-220.
• Yang, P. , Beasley, A., Eckermann, K., Swann, A., Dafny, N. Valproate prevents the induction of sensitization to methylphenidate (Ritalin) in rats, Brain Research 2000; 887: 276-284.
• Eckermann, K., Beasley, A., Yang, P. , Gaytan, O., Swann, A., Dafny, N. Methylphenidate sensitization is modulated by valproate, Life Sciences 2001; 69: 47-57.
• Yang, P. , Singhal, N., Modi, G., Swann, A., Dafny, N. Effects of lithium chloride on induction and expression of methylphenidate sensitization, European Journal of Pharmacology 2001; 426: 65-72.
• Yang, P.B. , Swann, A., Dafny, N. Valproate prevents the induction and the expression of MK-801 sensitization, Brain Research 2002; 954: 151-159 .
• Yang, P.B., Amini, B., Swann, A.C., Dafny, N. Strain differences in the behavioral responses of male rats to chronically administered methylphenidate, Brain Research 2003; 971: 139-152.
• Yang, P.B., Swann, A.C., Dafny, N. Chronic pretreatment with methylphenidate induces cross-sensitization with amphetamine, Life Sciences 2003; 73: 2899-2911.
• Prieto-Gomez, B., Benitez, M.T., Vazquez-Alvarez, A.M., Yang, P.B ., Reyes-Vazquez, C., Dafny, N. Dopaminergic ventral tegmental neurons modulated by methylphenidate, Life Sciences 2004; 74: 1581-1592.