Frog Prey Capture Behavior: Between Sensory Maps and Directed Motor Output

In frog prey capture behavior an appropriate sensory stimulus at a given location in space triggers a complex movement directed toward the stimulus. We are interested in how the frog brain is organized so as to yield such a spatial correspondence between a stimulus and the resulting movement. Initial stages of the neuronal circuitry underlying prey capture appear to involve topographic sensory representations in the midbrain. The prey capture outputs are triggered or ballistic, suggesting that they are based on pattern generating circuitry at some unknown location in the brain. Given these considerations, one approach to the problem of the spatial correspondence between stimulus and movement is to ask how topographic sensory maps are linked to pattern generating circuitry. In this paper we will discuss several experiments directed at exploring this linkage. We will focus particularly on how our ideas about the organization which brings about an appropriate correspondence between input and output have evolved during the course of these studies.