The Relationship Between Cholinergic and Noradrenergic Activity and Behavioral State

Presenter(s): John Francis—Biology

Faculty Mentor(s): Lindsay Collins, David McCormick

Session 5: The Wonders of the Brain

Observable changes in behavior result from complex network activity within the brain . Precise excitation and inhibition of neurons is partially regulated via neuromodulatory systems which regulate the behavior of other neurons, thereby producing observable changes in behavior . I plan to investigate the relationship between activity of two neuromodulatory cell types, cholinergic and noradrenergic neurons, and observable behavior in mice . Acetylcholine (ACh) and noradrenaline (NA) are produced and released by cholinergic and noradrenergic neurons, respectively, and have broad functions throughout the central nervous system . For instance, both ACh and NA neurons are more likely to fire during high arousal state, a physiological measure of alertness and attentiveness which is related to external metrics of brain state, like pupil diameter . My project will investigate the relationship between activity of ACh and NA neurons and arousal-linked behavior in three ways: 1) we will confirm the relationship between ACh and NA activity and arousal previously demonstrated in our lab and expand on this literature by including other behavioral measures such as whisker pad motion and tail motion in our analyses, 2) determine whether changes in ACh and NA activity precede or follow the onset of behavioral events, 3) determine the extent to which ACh or NA provides synchronous signals across the brain during arousal state fluctuations . Using systems neuroscience techniques such as intracranial viral injections, immunohistochemistry, and 2-photon microscopy, this project will further our current understanding of the relationship between ACh and NA activity and observable patterns of behavior in mice .