The long term goal of this research is to discover neural principles for the coordination of body movements. Specifically, this study will analyze the mechanisms of sensorimotor integration by the medial reticulospinal system. Such brain stem systems are essential for complex movements such as locomotion and orientation, but little is known about their underlying mechanisms. The proposed research will use an animal model -- the reticulospinal network that causes a distinctive escape maneuver in goldfish. Recent work shows that brain stem organization has been preserved during vertebrate evolution. Study of these animals can thus give crucial insights into the neural mechanisms of locomotor control. In addition, the reticulospinal neurons of these animals are experimentally accessible, the escape maneuver is easy to elicit, its kinematics are easy to analyze, and major components of the system are already well described. This project has three specific aims: 1) Neurons of the reticulospinal escape network will be identified by anatomical mapping and morphological characterization. These studies will use retrograde transport and staining of horseradish peroxidase, and intracellular injections of Lucifer Yellow. 2) Once the candidate neurons are identified, their neurophysiological features and inter-relationships will be described. These studies will use both extra- and intracellular recording techniques. 3) The neural processes for triggering and coordinating the behavior will be analyzed. These studies will combine high-speed kinematic, electromyographic and microlesion techniques. The feasibility of these studies is demonstrated by the current use of the requisite methods in ongoing experiments. Thus, this work can be anticipated to result in new information about the neural processes and anatomical connections for movement coordination in both and trauma.