9604408 Berridge This project investigates how neural systems in the brain control the sequential order of movements so as to produce effective, coordinated action. The neural system targeted by the project, the striatum, is known to control movement and some aspects of natural behavior, and in humans it also appears to help coordinate the sequence of words in language and the sequence of thought patterns. The goal of this project is to reveal the identity and characteristics of the crucial neural circuits within the striatum that are most involved in controlling sequential patterns of behavior, and to understand how they provide normal coordination. Experiments test the hypothesis that the sequencing circuit uses the neurotransmitter dopamine to communicate between neurons in the striatum in order to increase the strength of particular natural sequential patterns of action in an adaptive, goal-directed way. The project also examines how the striatum uses modulation of sensory processing and responsiveness to control sequential coordination of movements. The results of the project improve the understanding of how the brain coordinates normal behavior. They may also provide insights into the processes that are disturbed in human diseases that are characterized by abnormal sequences of movement or thought (for example, Huntington's Disease, Tourettes Syndrome, or obsessive- compulsive disorder),
