- Please provide a brief introduction about yourself.
I’m Dr. Ivy Hoang and I’m a behavioral neuroscientist. I was born and raised in the Bay Area by my Chinese and Vietnamese immigrant parents, and I am a first-generation college attendee and graduate. I’ve lived all across California, earning my B.S. in Physiology/Neuroscience at the University of California, San Diego (UCSD) in 2017 and most recently my Ph.D. in Psychology at the University of California, Los Angeles (UCLA) in 2024. I have now made my way back up to the Bay Area and I am currently a postdoctoral scholar at Stanford University.
- Tell us about your research project.
My doctoral work consists of two primary aims: the first is to characterize the function of a neural circuit comprised of the lateral hypothalamus (LH) and the ventral tegmental area (VTA) for learning about cues predictive of specific rewarding outcomes, and the second is to investigate how these neural and cognitive mechanisms are altered with a history of methamphetamine exposure to give rise to maladaptive reward-driven behaviors seen with substance use disorders. I used modern neuroscience techniques such as optogenetics to selectively target components of LH-VTA circuitry and fiber photometry to measure bulk dopamine release activity in LH in freely-behaving rats as they undergo tasks designed to assess their ability to acquire cue-reward associations and use these to guide their decision-making. To better model human drug use experiences in rodent behavior, I trained rats to voluntarily self-administer intravenous methamphetamine and subsequently assessed changes in their learning for reward cues as well as LH-VTA neural adaptations. In brief, I determined that the LH was critical for acquiring reward outcome representations used to influence behavior and an understudied pathway extending from VTA dopamine neurons to the LH works to mediate this function. Further, methamphetamine-experienced rats show enhancements in the use of outcome representations to direct their behavior towards those specific outcomes. This behavioral phenomenon was accompanied by a strengthening of LH-VTA circuitry and may potentially be driven by heightened cue-evoked dopamine release during learning for reward-predictive cues.
- What inspired your interest in this topic?
I have had long-standing interests in understanding the psychology and neuroscience of drug addiction since I was a kid. Growing up, I would see my father constantly smoking cigarettes, going through multiple packs weekly. I knew it wasn’t good for his well-being with long-term consequences to his health (he did as well), but he and the rest of my family passed it off to me as a bad habit he would never be able to kick. As I got older, I realized that his excessive cigarette intake was, more likely than not, nicotine dependence. I understood why he turned to smoking cigarettes, but I never understood why he could not quit, no matter how much he wanted to. Eventually, after more than 30 years of smoking, my dad did miraculously end up quitting cold turkey. Coincidentally, this also aligned with my initial endeavors in pursuing drug addiction research and fed more into my curiosity to study the psychopathology of the disorder. This led me to pursue my PhD with Dr. Melissa Sharpe at UCLA and allowed me to explore the underlying neural mechanisms of the cognitive processes contributing to maladaptive behaviors seen with substance abuse.
- This award recognizes the broader impact of your research project. What are the societal implications of your work?
Millions of people in the U.S. and globally are afflicted with a substance use disorder, and even more people know at least one person who suffers from one. Substance dependence is still largely stigmatized and many continue to view the disorder as the result of an ongoing habit, removing the individual entirely instead of perceiving them as a person struggling with a substance use disorder. My doctoral research opposes these habit models of drug addiction and urges for a more comprehensive understanding of the maladaptive drug use behaviors driving substance abuse. By identifying a neural substrate responsible for acquiring and employing cognitive representations of rewarding events that becomes altered with drug experience, this suggests that maladaptive drug-seeking may be under cognitive control and separates the automaticity in drug-seeking from the influence of drug-paired environmental cues over behavior. Ultimately, my hope is that this work will help to destigmatize drug addiction and lead to the discovery of novel approaches to treat individuals with a substance use disorder.
- What are your next steps academically/professionally?
I am currently in my first year as a postdoctoral researcher working with Dr. William Giardino in the Psychiatry and Behavioral Sciences department at Stanford University. Having explored some of the cognitive mechanisms underpinning substance use disorders in graduate school, I am now keen to investigate the homeostatic contributions to these processes. Specifically, I am interested in examining how drug-induced disturbances in sleep homeostasis may be shaping reward learning and memory and the involvement of neuronal subpopulations in the extended amygdala in these interactions. My overarching career goal is to continue my academic career trajectory and eventually transition into an independent investigator and lead my own addiction neuroscience research group. I hope to be able to build a strong, translationally-relevant research program rooted in curiosity, understanding, and community.
