Past events

Drug addiction is a chronically relapsing disorder characterized by compulsive drug use despite catastrophic personal consequences (e.g., loss of family, job) and even when the substance is no longer perceived as pleasurable. In this talk, I will present results of human neuroimaging studies, utilizing a multimodal approach (neuropsychology, functional magnetic resonance imaging, event-related potentials recordings), to explore the neurobiology underlying the core psychological impairments in drug addiction (impulsivity, drive/motivation, insight/awareness) as associated with its clinical symptomatology (intoxication, craving, bingeing, withdrawal). The focus of this talk is on understanding the role of the dopaminergic mesocorticolimbic circuit, and especially the prefrontal cortex, in higher-order executive dysfunction (e.g., disadvantageous decision-making such as trading a car for a couple of cocaine hits) in drug addicted individuals. The theoretical model that guides the presented research is called iRISA (Impaired Response Inhibition and Salience Attribution), postulating that abnormalities in the orbitofrontal cortex and anterior cingulate cortex, as related to dopaminergic dysfunction, contribute to the core clinical symptoms in drug addiction. Specifically, our multi-modality program of research is guided by the underlying working hypothesis that drug addicted individuals disproportionately attribute reward value to their drug of choice at the expense of other potentially but no-longer-rewarding stimuli, with a concomitant decrease in the ability to inhibit maladaptive drug use. In this talk I will also explore whether treatment (as usual) and 6-month abstinence enhance recovery in these brain-behavior compromises in treatment seeking cocaine addicted individuals. Promising neuroimaging studies, which combine pharmacological (i.e., oral methylphenidate, or RitalinTM) and salient cognitive tasks or functional connectivity during resting-state, will be discussed as examples for using neuroimaging in the empirical guidance for the development of effective neurorehabilitation strategies (including cognitive training) in drug addiction.

Understanding the functional communication across brain has been a long sought-after goal of neuroscientists. However, due to the widespread and highly interconnected nature of brain circuits, the dynamic relationship between neuronal network elements remains elusive. With the development of optogenetic functional magnetic resonance imaging (ofMRI), it is now possible to observe whole-brain level network activity that results from modulating with millisecond- timescale resolution the activity of genetically, spatially, and topologically defined cell populations. ofMRI uniquely enables mapping global patterns of brain activity that result from the selective and precise control of neuronal populations. Advances in the molecular toolbox of optogenetics, as well as improvements in imaging technology, will bring ofMRI closer to its full potential. In particular, the integration of ultra-fast data acquisition, high SNR, and combinatorial optogenetics will enable powerful systems that can modulate and visualize brain activity in real-time. ofMRI is anticipated to play an important role in the dissection and control of network-level brain circuit function and dysfunction. In this talk, the ofMRI technology will be introduced with advanced approaches to bring it to its full potential, ending with examples of dissecting whole brain circuits associated with neurological diseases utilizing ofMRI. Short Bio: Dr. Lee received her Bachelor’s degree from Seoul National University and Masters and Doctoral degree from Stanford University, all in Electrical Engineering. She is a recipient of the 2008 NIH/NIBIB K99/R00 Pathway to Independence Award, 2010 NIH Director’s New Innovator Award, 2010 Okawa Foundation Research Grant Award, 2011 NSF CAREER Award, 2012 Alfred P. Sloan Research Fellowship, 2012 Epilepsy Therapy Project award, 2013 Alzheimer’s Association New Investigator Award, 2014 IEEE EMBS BRAIN young investigator award, and the 2017 NIH/NIMH BRAIN grant award. As an Electrical Engineer by training with Neuroscience research interest, her goal is to analyze, debug, and engineer the brain circuit through innovative technology. 1. Hyun Joo Lee†, Andrew Weitz†, David Bernal-Casas, Ben A. Duffy, Mankin Choy, Alexxai Kravitz, Anatol Kreitzer, Jin Hyung Lee*, Activation of direct and indirect pathway medium spiny neurons drives distinct brain-wide responses, Neuron, 2016;91(2):412-424. 2. Jia Liu†, Ben A. Duffy†, David Bernal-Casas, Zhongnan Fang, Jin Hyung Lee*, Comparison of fMRI analysis methods for heterogeneous BOLD responses in block design studies, Neuroimage, 2017;147:390-408. 3. David Bernal-Casas, Hyun Joo Lee, Andrew Weitz, Jin Hyung Lee*, Studying brain circuit function with dynamic causal modeling for optogenetic fMRI, Neuron, 2017;93:522-532.

Social animals have to know the spatial positions of conspecifics. However, it is unknown how the position of others is represented in the brain. We designed a spatial observational-learning task, in which an observer bat mimicked a demonstrator bat while we recorded hippocampal dorsal-CA1 neurons from the observer bat. A neuronal subpopulation represented the position of the other bat, in allocentric coordinates. About half of these “social place cells” represented also the observer’s own position—that is, were place cells. The representation of the demonstrator bat did not reflect self-movement or trajectory planning by the observer. Some neurons represented also the position of inanimate moving objects; however, their representation differed from the representation of the demonstrator bat. This suggests a role for hippocampal CA1 neurons in social-spatial cognition.