Neuronal Mechanisms of Feeding Arousal

Arizona State University, Scottsdale AZ

Investigators

Abstract

Neuronal Mechanisms of Feeding Arousal Tigran Norekian An important feature for understanding behavioral responses is the concept of a motivational state. Motivational states ensure that an animal engages in a specific behavioral activity with maximum efficiency. Although a basic understanding of a motivational state can be explored on the behavioral level, little is known about its cellular mechanisms in any single organism. Such cellular mechanisms are best studies in preparations in which the underlying neural circuits are relatively simple and well characterized. One such example is the predatory mollusk Clione - an extreme food specialist with a very sporadic food supply. When food is available, Clione demonstrates a very dramatic change in its behavior that can be described as a feeding arousal motivational state. The main goal of this project is to identify specific modifications in the Clione brain, which create the feeding arousal motivational state. First, we will identify specific modifications in a number of identified neurons during food-induced arousal. The primary hypothesis is that during feeding arousal neurons controlling feeding behavior are activated or their excitability is increased, while neurons controlling other competing or irrelevant behaviors are inhibited. The second objective will be to identify the source of these widespread modulatory changes in the brain. The focus will be on the neurons employing serotonin as their transmitter. It is suggested that during feeding arousal many serotonergic neurons are activated in concert. The integrated influence of these neurons would be the excitation of neurons producing feeding behavior and inhibition of neurons controlling competing behaviors - in other words, creation of a feeding arousal motivational state. The proposed work will provide important information about the neural organization of the feeding arousal motivational state in a simple preparation. Understanding the neurobiology of a motivational state in one simple system will further advance our understanding of motivational states in all animals, therefore obtained results should have a broad impact. The proposed activity will also develop further international collaboration and partnership with a Russian team of scientists.