ABSTRACT
Prescription opioids, such as oxycodone, remain a common treatment for pain disorders. Although effective in
the short-term, long-term use can result in tolerance, dependence and fatal overdose. While oxycodone is not
the primary driver of fatal overdoses from opioids, the exposure to and subsequent withdrawal from oxycodone
can lead susceptible individuals to relapse, potentially substituting intake fentanyl or other more potent
synthetic opioids. Thus, understanding the mechanisms of oxycodone-induced withdrawal will provide a better
foundation for the treatment of opioid use disorder. The central nucleus of the amygdala (CeA) is an integrative
brain region that contributes to the generation of negative affective states. Prior work has demonstrated
increased neuronal excitability within the CeA in rodent models of morphine withdrawal, and inhibition or lesion
of the CeA resulted in a reduction of the aversive, and, to a lesser extent, somatic withdrawal behaviors from
morphine. Most studies investigating the CeA’s role in opioid withdrawal have done so in a global sense,
ignoring potential contributions of specific cell types to the manifestation of opioid withdrawal behaviors. The
central hypothesis in the present application is that activation of molecularly distinct neuronal subpopulations
within the CeA are necessary and sufficient for the expression of somatic opioid withdrawal and contribute to
future drug seeking behaviors. Uncovering the specific subtypes responsible for the expression of opioid
withdrawal has the potential to lead to a more effective and specialized approach for the development of
treatments of opioid use disorder. To this end, I will employ the use of targeted recombination in active
populations mice, which express the tamoxifen-dependent CreERT2 recombinase from the Fos promoter to
gain genetic access to oxycodone withdrawal activated (OWA) neurons. Using this strategy, I propose to
evaluate the activity of OWA during oxycodone withdrawal and evaluate their contributions to the expression of
behaviors related to somatic withdrawal and negative affect. In Aim 2, I will seek to use both known probes and
single-cell RNA sequencing to identify CeA neuronal populations preferentially activated during oxycodone
withdrawal. In the independent (R00) phase I will evaluate different subpopulations of CeA neurons based on
hits from Aim 2. Highly enriched projections and genes will be evaluated for their ability to influence behaviors
pertaining to oxycodone withdrawal and seeking. These experiments will provide me with an outstanding
technical skillset and an enriched data set to build the foundation of my independent research program
studying the framework of the CeA during opioid dependence and withdrawal. The results of these
experiments will provide a clearer understanding of the CeA’s role during opioid withdrawal, potentially to
leading to more targetable treatments for opioid use disorder.