Abstract
In the past 20 years, neuroscientists have focused on circuit-specific manipulations of the brain to identify
neuronal pathways controlling nicotine dependence and relapse using bioengineering approaches, such as
optogenetics and calcium imaging. These approaches have determined a causal relationship between
activation of localized neurons by nicotine and specific nicotine-related behaviors. However, we still have very
little understanding of how the brain, as a whole, processes this information because of a technical gap making
it difficult to image the whole brain at single-cell resolution. This is a critical problem for the field, as nicotine,
pharmacological and behavioral treatments affect the brain as a whole and not just specific circuits. The recent
development of single-cell whole-brain imaging of immediate-early genes using light-sheet microscopy on
cleared brains (iDisco+) has made the study of brain-wide functional networks at single-cell resolution possible.
The overarching hypothesis is that coordinated activation of long-range cholinergic neurons is associated with
decreased whole-brain modularity and withdrawal-related behaviors that can be partially normalized using
FDA-approved medications. The first goal of this proposal is to identify brain-wide functional networks at
single-cell resolution associated with acute nicotine intoxication, chronic nicotine dependence, withdrawal, and
protracted abstinence using iDisco+ imaging of immediate-early genes. The second goal is to identify the brain
activity patterns that control these states and predict the acute and long-term physiological and behavioral
response to nicotine using advanced neural network analyses. The third goal is to test the hypothesis that
FDA-approved medications will normalize these network changes. This project will lead to four outcomes that
will likely produce a long-lasting impact on the field: 1) Identification of the functional brain networks of acute
nicotine, nicotine dependence, acute withdrawal, and protracted abstinence. 2) Molecular phenotyping of the
functional network. 3) Identification of the major hub regions that predict withdrawal-related behaviors. 4)
Characterization of the brainprints of FDA-approved medications for tobacco use disorder. 5) Testing the
theory that coordinated activation of long-range cholinergic neurons is associated with decreased whole-brain
modularity and withdrawal-related behaviors.