Wayne Pratt

My research interests are focused on understanding the neurobiological substrates that underlie the brain’s encoding of natural rewards. In particular, I am interested in how rewards are signaled and communicated between brain regions, and how neural circuits select adaptive behaviors based on motivation and reinforcement history. As such, the research done in my laboratory examines brain function and behavior related to motivation, learning, and memory.

Using the rat as an experimental model, and employing behavioral pharmacological techniques, my students and I examine how neurotransmitter systems interact in brain reward pathways to direct motivated behavior. More specifically, recent research in my laboratory has characterized the role of individual neurotransmitter receptors in the rat nucleus accumbens and ventral tegmentum on food intake (consumption) and food-seeking (as expressed by willingness to work for sugar reward). The nucleus accumbens and ventral tegmentum are brain regions that are involved in learning about and directing behavior towards stimuli in the environment that are rewarding or predict rewarding outcomes. Together with other neural circuits, these regions direct voluntary behavior based upon reinforcement history and have been heavily implicated in the neurobiology of drug addiction. Recent evidence suggests that the nucleus accumbens and its interconnected circuitry also play an important role in promoting food intake in response to the presentation of particularly palatable, rewarding foods. The proliferation of such diets in modern culture is likely one of the multiple environmental factors that underlies the current obesity epidemic.

Since 2009, students and I have published on the roles of nucleus accumbens acetylcholine, opioid, cannabinoid, dopamine, and serotonin receptors on various aspects of feeding and food-directed motivation. Currently, we are systematically examining the roles of individual serotonin receptor subtypes within the nucleus accumbens and ventral tegmentum on food-directed behaviors. The project is supported by a grant from the National Institute of Drug Abuse (R15 DA030618).

Selected Recent Publications:

Central and systemic regulation of food consumption (Italics indicate WFU student authors):

• Clissold, K. A., Choi, E., & Pratt, W. E. (2013). Serotonin 1A, 1B, and 7 receptors of the rat medial nucleus accumbens differentially regulate feeding, water intake, and locomotor activity. Pharmacology Biochemistry and Behavior, 112, 96-103. [PDF]
• Pratt, W. E., Choi, E., & Guy, E. G. (2012). An examination of the effects of subthalamic nucleus inhibition or µ-opioid receptor stimulation on food-directed motivation in the non-deprived rat. Behavioural Brain Research, 230(2), 365-73. [PDF]
• Skelly, M.J., Guy, E. G., Howlett, A. C., & Pratt, W. E. (2010). CB1 receptors modulate the intake of a sweetened fat diet in response to mu-opioid receptor stimulation of the nucleus accumbens. Pharmacology Biochemistry and Behavior, 97, 144-151. [PDF]
• Pratt, W. E. & Connolly, M. E. (2010). Contrasting effects of systemic and central sibutramine administration on the intake of a palatable diet in the rat. Neuroscience Letters, 484, 30-34. [PDF]
• Pratt, W. E., Blackstone, K., Connolly, M., & Skelly, M. J. (2009). Selective Serotonin Receptor Stimulation of the Medial Nucleus Accumbens Causes Differential Effects on Food Intake and Locomotion. Behavioral Neuroscience, 123(5):1046-57. [PDF]
• Pratt, W. E., & Blackstone, K. (2009). Nucleus accumbens acetylcholine and food intake: Decreased muscarinic tone reduces feeding but not food-seeking. Behavioural Brain Research, 198(1), 252-257. [PDF]

Central and systemic modulation of appetitive food-seeking behavior (Italics indicate WFU student authors):

• Pratt, W. E. & Ford, R. T. (2013). Systemic treatment with d-fenfluramine, but not sibutramine, blocks cue-induced reinstatement of food-seeking behavior in the rat. Neuroscience Letters, 213, 232-37. [PDF]
• Pratt, W. E., Schall, M. A., & Choi, E. (2012). Selective serotonin receptor stimulation of the medial nucleus accumbens differentially affects appetitive motivation for food on a progressive ratio schedule of reinforcement. Neuroscience Letters, 511(2), 84-88. [PDF]
• Guy, E. G., Choi., E., & Pratt, W. E. (2011). Nucleus accumbens dopamine and mu-opioid receptors modulate the reinstatement of food-seeking behavior by food-associated cues. Behavioural Brain Research, 219(2), 265-72. [PDF]

Recent Reviews/Theoretical Contributions

• Stice, E.., Figlewicz, D. P., Gosnell, B.A., Levine, A.S., & Pratt, W. E. (2013). The contribution of brain reward circuits to the obesity epidemic. Neuroscience and Biobehavioral Reviews, 37, 2047-58. [PDF]
• Baldo, B. A., Pratt, W. E., Will, M. J, Hanlon E. C., Bakshi,V.P., & Cador, M. (2013). Principles of motivation revealed by the diverse functions of neuropharmacological and neuroanatomical substrates underlying feeding behavior. Neuroscience and Biobehavioral Reviews, 37, 1985-98.

• First Year Seminar – We can, but should we? Ethical Questions at the Cutting Edge of Scientific Research
• Psychology 243 – Biopsychology
• Psychology 312 – Research Methods in Psychology II
• Psychology 326 – Learning Theory and Research
• Psychology 320 – Physiological Psychology
• The Motivation segment of the Neuroscience Minor core course (NEU 200)