The Yorgason laboratory is interested in understanding the neural correlates of reward and reinforcement learning. Using functional microscopy, electrophysiology, electrochemistry and behavioral approaches, we examine the neurobiology of reinforcement learning and drug-induced changes in neural activity in reward related brain regions> Much of the lab work has focused on studying the mesolimbic and nigrastriatal dopamine system. Midbrain dopamine neurons project throughout the striatum, and their signaling is complex and dependent on inputs from other regions. In addition, release from terminals can occur completely independent of dopamine cell firing. Our laboratory is interested in studying the circuitry mechanisms that drive release during reward learning.
Jordan Yorgason, PhD
Current Research Focus
The laboratory has a large focus on developing new tools for studying neural and behavioral correlates of motivation and reward seeking. Dr. Yorgason developed Demon Voltammetry Software (https://pubmed.ncbi.nlm.nih.gov/21392532/) and designed low noise voltammetry amplifiers in collaboration with Drs. Shihua Wood (BYU Department of Electrical Engineering) and Dr. Scott Steffensen (BYU Psychology). Alongside Ryan West (MS student in Software Engineering), we have developed new virtual reality software for rodents. This software is currently being validated in collaboration with the laboratory of Dr. Cody Siciliano (Vanderbilt). With James Brundage (MS student in Neuroscience) and Dr. David Hedges (Billings Clinic), the lab is developing new tools in analysis for electrophysiology and electrochemistry.
Current laboratory interests can be broken down into three general areas:
1. Enzymatic function of 12 transmembrane solute carriers such as the dopamine transporter. Using electrochemistry techniques, the laboratory examines alterations in function for transporters. The lab is currently examining function of the dopamine transporter, including regional differences in post-translational modifications and associated activity in transporter function and trafficking. This work is currently led by Joakim Ronstroem who is a graduate student in the Neuroscience program and has a strong background in biochemistry processes and applied mathematics.
2. Examining sex differences in dopamine transmission. The lab uses electrochemistry and electrophysiology tools to examine dopamine terminal function in males and females. Recent MS graduate James Brundage initiated this project with his work on sex and regional differences in dopamine transmission. This work examined spontaneous dopamine release throughout the striatum and compared release across regions and between females and males. Current PhD student Hillary Wadsworth (Neuroscience) is continuing this work by examining sex dependent effects and the role of stress hormones on dopamine related circuitry. We have also recently accepted Zak Estrada into the lab, who will be initially helping with this project as he develops his own dissertation.
3. The laboratory has been developing new tools for measuring behavior in freely moving animals using virtual reality technology. Ryan West (MS student, Software Engineering) has been our principle programmer on this project and is accompanied by our statistician Colin Mason and our bioinformatics specialist Noah Moffat who have been developing the analytical tools. These tools are accompanied by treadmills that have been developed and prototyped in the laboratory. The primary goal is to develop tools for performing quality physiology recordings in head restrained animals while probing different aspects of behavior in a minimally invasive preparation. These tools will be provided to others as their use is validated and refined.
For updates in laboratory activity, follow us on the twitter (@JordanYorgason).