Peptidergic Modulation of Synaptic Circuitry in the Dorsal Vagal Complex

Tulane University, New Orleans LA

Investigators

Abstract

0080322 Smith The objective of this project is to advance understanding of how certain brain cells communicate in order to process sensation from the viscera (i.e., the stomach, lungs, heart, etc.). Sensory nerves in the viscera communicate directly with a set of brain cells, which are called neurons, in a small region of the lower part of the brainstem. These brainstem neurons communicate with each other to integrate digestive, cardiovascular and other autonomic functions. A number of chemicals made in other brain regions help regulate this communication, including a newly discovered brain chemical called hypocretin, which acts within the brain to generally increase autonomic behaviors. The general hypothesis of this project is that hypocretin modifies specific types of neuronal communication within the brainstem in a manner consistent with the chemical's effects on autonomic function. Using state-of-the-art electrical recording and optical imaging methods to study neuronal communication and anatomy, the functional organization of the viscera-related part of the brainstem will be determined, and the effects of hypocretin on that circuitry will be examined in the context of the chemical's reported general excitatory characteristics. Results of these experiments will lead to a better understanding of how neurons in the brainstem communicate with each other, as well as how chemical input from other brain areas can influence this communication. In addition, the results will help scientists better understand how neurons communicate with each other in general, and how various aspects of visceral function might be modified by chemicals acting within the brainstem.