Dr. Ian Mendez

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The primary goal of Dr. Mendez’s research is to understand how the circuits of the brain reward system become dysregulated and how these changes contribute to impairments in motivational, hedonic, and cognitive processes. Recent experiments have investigated aberrant reward seeking and taking behaviors, impaired economic cost-benefit decision making, and how brain reward systems interact with metabolic mechanisms to promote feeding disorders and obesity. These processes are relevant to a myriad of psychiatric disorders, with particularly strong implications for addiction.

 Significance of the work

Neurotransmitter systems in the brain reward system work together to orchestrate the seeking and taking of natural rewards that are critical for our survival. Unfortunately, the vulnerability of the reward system lies in its nature. The brain reward system is so efficient at driving behavior towards rewards that, under certain conditions, it can occur excessively. With repeated exposure and a genetic predisposition, drugs of abuse can eventually “hijack” the brain reward system and generate a powerful and life-long addictive state. Psychopathological conditions characterized by impaired reward processing have been responsible for hundreds of thousands of deaths and billions of dollars in costs associated with crime, lost work productivity, and health care. It is these staggering statistics that highlight the need for advancing treatment strategies and ultimately drive my research interests.

Research questions

Specifically our research will address the following questions:

  • What role do cholinergic receptors play in cost-benefit decision making and what are the effects of long-term nicotine vapor exposure on risky and impulsive choice?

  • How do the direct and indirect pathways in the basal ganglia work together to control cue-induced increases in reward seeking behavior?

  • What are the specific contributions of the various opioid neuropeptides in feeding behavior and energy regulation?

Methods to be learned

Dr. Mendez's research team investigates the brain reward system by utilizing animal models of mental heal and experimental methods in psychology, biology, genetics, and neurochemistry. Common techniques implemented in the Mendez lab include complex behavioral analysis, in situ hybridization and immunohistochemistry, and particularly, behavioral pharmacology. Behavioral methods frequently test reward discounting, Pavlovian and instrumental learning, incentive sensitization, and feeding microstructure. SMART MiND students investigating addiction in the Dr. Mendez laboratory will be exposed to a variety of neuroscience techniques and an interdisciplinary approach to research.