I am going into my fifth year at American University as a Ph.D. student. My earlier work at AU focused on assessing strain-dependent differences in the motivation to engage in and expression of sexual behavior in male rats of the inbred Lewis and Fischer 344 and outbred Sprague-Dawley strains (Hurwitz and Riley, 2011). More recently my research interests have focused on gaining an understanding of factors (e.g. age of exposure, strain, stress, history) that influence the balance between the rewarding and aversive properties of drugs and how modulation of these factors impact subsequent drug taking behavior.
Drug use and abuse is said to be a function of the relative balance between the drug’s rewarding and aversive effects with the aversive effects being seen as a rate-limiting factor on intake. Given the host of neurobiological changes that occur throughout adolescence, individuals may be particularly susceptible to drug use and abuse during this stage of development. It is thus possible that any age-dependent differences in morphine’s aversive effects may impact subsequent drug intake. I recently developed a procedure to assess the ability of morphine to induce taste aversions in adolescent and adult Sprague-Dawley rats. This initial work revealed that adolescents are less sensitive to the aversive properties of morphine relative to adults, an effect not simply due to differences in learning and memory, taste processing or motivation (Hurwitz, Merluzzi and Riley, 2012).
I will use similar procedures to evaluate morphine-induced aversions in inbred Lewis and Fischer 344 rats in hopes of isolating ontogenetically when aversions develop to better understand their basis. Furthermore, I have been developing methods to isolate and quantify morphine and its two primary metabolites (morphine-3-glucuronide and morphine-6-glucuronide) in plasma and brain tissue via high-performance liquid-chromatography with both UV-VIS and Coulochem III detection. I will correlate the aforementioned behavioral assessments with any differences found in the biochemical assays in hopes of discovering neural and physiological correlates for any observed differences. With a better understanding of their basis, it may be possible to develop a way to increase a drug’s aversive effects to limit or abolish intake to aid in the treatment (and hopefully) prevention of addiction.
Hurwitz ZH, Merluzzi AP, Riley, AL. A determination of the ontogenesis of morphine-induced taste aversions in the Lewis and Fischer 344 rats: A behavioral and neurochemical assessment (in preparation).
Merluzzi, AP, Hurwitz, ZH, Rice, KC, Riley, AL. A behavioral and neurochemical assessment of adolescent and adult differences in 3,4-methylenedioxypyrovalerone (MDPV)-induced taste aversions (in preparation).
Hurwitz ZH, Merluzzi AP, Riley AL. Age-dependent differences in morphine-induced taste aversions. Dev Psychobiology 2012. [PDF]
Kohut, SJ, Decicco-Skinner, KL, Johari, S, Hurwitz, ZE, Baumann, MH, and Riley, AL (2012). Differential modulation of cocaine’s discriminative cue by repeated and variable stress exposure: Relation to monoamine transporter levels. Neuropharmacology. [PDF]
Hurwitz, ZE, Riley, AL. The differential expression of male sexual behavior in the Lewis, Fischer and Sprague-Dawley rat strains. Learn Beh 2011, 39(1). [PDF]
Kohut, SJ, Christensen, CJ, Hurwitz, ZE, Silberberg, A, Riley, AL. Demand for alcoholic and nonalcoholic beer in naïve and experienced rats in preparation.
Westerman, AT, Roma, PG, Creed, ET, Hurwitz, ZE, Dominguez, JM (2009). The antiepileptic primidone impairs male rat sexual behavior. Pharmacol Biochem Beh 2009; 93(2): 160-4.
Hurwitz, ZE, Merluzzi, AP, Riley, AL (2012, June). Age-dependent differences in morphine-induced taste aversions. College on Problems of Drug Dependence, Palm Springs, FL.
Hurwitz, ZE, DeCicco-Skinner, KL, Riley, AL, Kohut, SJ (2011, November). Differential modulation of cocaine’s discriminative cue by predictable and unpredictable stress in rats. Society for Stimulus Properties of Drugs Meeting, Washington, DC.
Hurwitz, ZE, Riley, AL (2011, April). Escalation of cocaine self-administration in the Lewis, Fischer and Sprague-Dawley rat strains. Robyn Rafferty Research Conference, American University, Washington, DC.
Hurwitz, ZE, Riley, AL (2010, April). The differential expression of male sexual behavior in the Lewis, Fischer and Sprague-Dawley rat strains. Experimental Biology Conference, Anaheim, CA.
Hurwitz, ZE, Kohut, SJ, Christensen, CJ, Silberberg, A, Riley, AL (2009, April). An economic analysis of alcoholic and nonalcoholic beer drinking in rats exposed to daily restraint stress or handling. Robyn Rafferty Research Conference, American University, Washington, DC.
Hurwitz, ZE (2011, November). An assessment of morphine-induced taste aversions in adolescent Sprague-Dawley rats, Addiction: Adolescent Drug Abuse Pharmacology Nanosymposium at Neuroscience, Washington, DC.
Hurwitz, ZE (2011, August). The differential expression of male sexual behavior in the Lewis, Fischer and Sprague-Dawley rat strains, 5th Annual Psychological Science Graduate Student Superstars – Datablitz at the American Psychological Association Conference, Washington, DC.
Hurwitz, ZE (2009, March). Hormones, differentiation and associated disorders, American University, Washington, DC.
Hurwitz, ZE (2008, October). The neurobiology of drug use and abuse, American University, Washington, D.C. (October 2008).
Hurwitz, ZE (2008, November). Sexual differentiation: An important role for hormones, American University, Washington, DC.