9603976 Truman To be adaptive, an animal's behavior must change depending on the organism's physiological and developmental state. The behavior is typically organized in stereotyped sequences that progress through discrete behavioral phases each characterized by its suite of motor acts. Neuropeptides, small protein-like substances that are released into the blood or locally within the nervous system, are thought to play important roles in inducing and maintaining such behavioral phases. Using a relatively simple invertebrate system, Dr. Truman is examining how specific behaviors are controlled by these peptide modulators. He has proposed a model in which each behavioral phase is controlled by a different neuromodulator. Employing a variety of electrophysiological, neurochemical, and molecular and genetic techniques with a combination of in vitro and in vivo analyses, Dr. Truman will examine whether a hierarchy of neuroendocrine interactions is then responsible for the progression through a specific behavioral sequence. He will determine whether the basic organization of this cascade is that the hormone modulator directing the behavior for one phase also acts on the neuroendocrine cells that contain the neuromodulator for the next phase. The results from this comprehensive series of studies will provide new knowledge on the role of neuropeptides in the functioning of the nervous system and the mechanisms used by peptides to alter behavior. This fundamental research may also serve as the foundation for the development and application of practical procedures in controlling agricultural and medical insect pests.
