Assistant Professor
Department of Psychology

Office:1042C BSB
Phone: (312)-996-3113
Email: mroitman@uic.edu
Mailing Address:
1007 W. Harrison St. (MC 285)
Chicago, IL 60607-7137

Education:
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Ph.D., University of Washington, Seattle, WA
B.A., Cornell University, Ithaca, NY

Research Interests
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Motivated behavior, reward, aversion, feeding, obesity, drug addiction, dopamine, limbic circuitry, basal ganglia

Statement of Research Interests:
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My lab is interested in determining the neural basis of normal motivated behaviors including feeding and drinking as well as maladaptive behaviors such as drug-taking and the over-consumption associated with obesity. The nucleus accumbens and the neurotransmitter dopamine are critical brain substrates involved in motivated behavior including feeding and drug-taking. They appear to be vital to reward-related learning as well. Since the nucleus accumbens accesses motor-related structures it is well suited to modulate behavior based on changes in motivational state and learned associations. Our research seeks to determine how signaling in the nucleus accumbens is altered in response to changes in motivated state and learned associations. To accomplish this, we employ two state-of-the-art recording techniques combined with detailed behavioral analyses. Electrophysiological recordings of many single neurons and electrochemical recordings of dopamine release in the nucleus accumbens are made in real-time during behavior. These two recording techniques are performed while rats taste rewarding and aversive stimuli or are working to obtain food or drug rewards. Learned associations are manipulated by pairing a rewarding taste with illness thereby rendering it aversive in the future. Motivational state is altered by food or water restriction or by the delivery of hormones or neuropeptides to mimic need-states or satiety. Finally, we are interested in whether the propensity to take drugs, such as cocaine, can be altered through the delivery of hormones or neuropeptides that affect food intake. This program or research will shed considerable light on human disorders of motivation such as obesity and drug-addiction.

Figure 1. Recordings made in awake and behaving rats. Top: Color representation of dopamine (seen as the green features) signaling in real-time using fast-scan cyclic voltammetry. Left, example. Right, time-averaged over 30 minutes. Bottom: Simultaneous recordings of many individual neurons in the nucleus accumbens and electromyographic recording of the anterior digastric muscle.

Selected Publications:
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Ph Roitman, MF (2006) Persistent hunger for sodium makes brain stimulation not so sweet: theoretical comment on Morris et al. (2006). Behavioral Neuroscience, 120, 744-747.

Day, JJ, Wheeler, RA, Roitman, MF & Carelli, RM (2006) Nucleus accumbens neurons selectively encode reward prediction and Pavlovian approach behavior. The European Journal of Neuroscience, 23, 1341-1351.

Wheeler, RA, Roitman, MF, Grigson, PS & Carelli, RM (2005) Single neurons in the nucleus accumbens track relative reward. International Journal of Comparative Psychology, 18: 320-332.

Roitman, MF, Wheeler, RA & Carelli, RM (2005) Nucleus accumbens neurons are innately tuned for rewarding and aversive taste stimuli, encode their predictors, and are linked to motor output. Neuron 45, 587-597.

Stuber, GD, Roitman, MF, Phillips, PEM, Carelli, RM & Wightman, RM (2004) Rapid dopamine signaling in the nucleus accumbens during contingent and non-contingent cocaine administration. Neuropsychopharmacology doi:10.1038/sj.npp.1300619.

Roitman, MF, Stuber, GD, Phillips, PEM, Wightman, RM & Carelli, RM (2004) Dopamine operates as a subsecond modulator of feeding. Journal of Neuroscience 24, 1265-1271.

Roitman, MF, Na, E, Anderson, GA, Jones, TA & Bernstein, IL (2002) Induction of a salt appetite alters dendritic morphology in nucleus accumbens and sensitizes rats to amphetamine. Journal of Neuroscence 22, 1-5.