377. Involvement of the vagus nerves and associated CNS pathways in psychiatric disorders

A large body of basic science research provides evidence for the involvement of peripheral afferent branches of the vagus in a wide range of functions including, but not limited to, control of meal termination, memory storage, exploratory behaviors, sleep, and modulation of somatic pain detection. The implications of these basic science findings to human behavior in general, and to psychiatric disorders in specific, have just recently become the subject of clinical investigations. The overall goal of this workshop is to present existing evidence supporting vagal afferent involvement in both the pathophysiology of bulimia nervosa and in human memory storage. Two different methods for modulation of peripheral vagal neurotransmission will be presented and discussednamely the use of ondansetron (Zofran) as a pharmacological modulator of vagal activity and the implantation of Vagal Nerve Stimulators (Cyberonics) for direct unilateral electrical stimulation of vagal fibers. Investigators from the University of Minnesota will present physiological (Dr. Faris), clinical outcome (Dr. Eckert), and neuroanatomical (Dr. Hartman) findings supporting vagal involvement in the perpetuation of both primary bulimic symptoms and also depressive symptoms in severely ill bulimia nervosa patients using ondansetron treatment to modulate vagal activity. Dr. Jensen will present data demonstrating an enhancement of memory in human subjects by direct vagal nerve stimulation at specific stimulation frequencies. This workshop will provide a timely presentation of potential vagal involvement in the pathophysiology of psychiatric disorders.