*** Dr. Harrod is accepting students for Fall 2022 ***

Research

We are investigating factors that influence the vulnerability for drug abuse.  Our interests include (1) how prenatal nicotine exposure alters drug motivated behavior in offspring; (2) if novel drugs have the ability to decrease drug taking behaviors; and (3) whether the sex of the animal influences various drug effects.

Why are the effects of prenatal nicotine important?

Maternal tobacco smoking occurs in ~13% of women in the United States.  Children exposed to maternal smoking exhibit a myriad of health problems.  For example, ADHD and substance abuse occur at a higher frequency in children of maternal smokers compared to offspring that were not exposed to prenatal tobacco smoke.

Our research investigates the neurobehavioral consequences of nicotine by administering intravenous nicotine 3X/ day to pregnant rats throughout the gestational period.  We are particularly interested in the behavioral effects that prenatal intravenous nicotine produces in the male and female offspring.  We investigate cocaine and methamphetamine self-administration; sucrose maintained responding; locomotor activity, and conditioned taste preference.  We are also investigating the neurochemical changes produced by prenatal intravenous nicotine in brain regions that organize motivated behavior.  Both adolescent and adult offspring are being investigated.

Can new drugs be used to help people with their addictions?

Our laboratory also examines potential pharmacotherapies for methamphetamine addiction.  Currently, there are no treatments available to help methamphetamine users curtail their drug use.  In these experiments, we determine if novel compounds reduce methamphetamine self-administration in rodent subjects.  Our research also tests whether the compound exhibits abuse liability.

Do males and females show differences in their behavioral response to abused drugs?

Sex differences from the effects of abused drugs are well documented.  We are interested in whether males and females respond differently to prenatal nicotine treatment, and if novel drugs that are developed to help reduce drug taking behavior affect males and females differently.

Our research is not possible without funding from the National Institutes on Drug Abuse (DA 021287) or the Research Productivity Scholarship (KA-21) awarded from the University of South Carolina.

Representative Publications:

Harrod SB, Klebaur JE, Crooks PA, Dwoskin LP, Bardo MT. (2001). Lobeline attenuates d-methamphetamine self-administration in rats. Journal of Pharmacology and Experimental Therapeutics, 298, 172-179.

Harrod SB, Dwoskin LP, Green TA, Gerhke B, Bardo MT. (2003). Lobeline does not serve as a reinforcer in rats. Psychopharmacology, 165, 397 - 404.

Gehrke BJ, Harrod SB, Cass WA & Bardo MT. (2003). The effect of neurotoxic doses of methamphetamine on methamphetamine conditioned place preference in rats. Psychopharmacology, 166, 249 - 257.

Harrod SB, Dwoskin LP, & Bardo MT. (2004). Lobeline produces conditioned taste avoidance in rats. Pharmacology, Biochemistry & Behavior, 78(1), 1-5.

Harrod SB, Booze RM, Mactutus CF. (2007). Sex differences in nicotine levels following repeated intravenous injection in rats are attenuated by gonadectomy. Pharmacol Biochem Behav. 86, 32-36.

Neugebauer NM, Harrod, SB, Stairs DJ, Crooks PA, Dwoskin LP, Bardo MT. (2007). Lobelane decreases methamphetamine self-administration in rats. Eur J Pharmacol. 571, 33-38.

Harrod, S.B., Mactutus, C.F., Fitting, S., Hasselrot, U., Booze, R.M. (2008). Intra-accumbal Tat1-72 alters acute and sensitized responses to cocaine. Pharmacol Biochem Behav. 90, 723-729.

Harrod SB, Van Horn ML. (2009). Sex differences in tolerance to the locomotor depressant effects of lobeline in periadolescent rats. Pharmacol Biochem Behav. 94, 296-304.

Neugebauer NM, Harrod SB, Bardo MT. (2010). Nicotine elicits methamphetamine-seeking in rats previously administered nicotine. Drug Alcohol Depend. 106(1), 72-78.

Harrod S.B., Lacy, R.T., Ballina, L.E. (2010). Persistent expression of methamphetamine-induced CTA in periadolescent rats. Pharmacol Biochem Behav. 96(4), 515-520.

Lacy, R.T., Mactutus, C.F., Harrod, S.B. (2011). Prenatal IV nicotine exposure produces a sex difference in sensorimotor gating of the auditory startle reflex in adult rats. International Journal of Developmental Neuroscience, .

Horton, D.B., Siripurapu, K.B., Norrholm, S.D., Culver, J.P., Hojahmat, M., Beckmann, J.S., Harrod, S.B., Deaciuc, A.G., Bardo, M.T., Crooks, P.A., and Dwoskin, L.P. (2011). Meso-Transdiene Analogs Inhibit Vesicular Monoamine Transporter-2 Function and Methamphetamine-evoked Dopamine Release. Journal of Pharmacol Exp Ther, .

Midde NM, Gomez AM, Harrod SB, Zhu J. (2011). Genetically expressed HIV-1 viral proteins attenuate nicotine-induced behavioral sensitization and alter mesocorticolimbic ERK and CREB signaling in rats. Pharmacol Biochem Behav, .