PROJECT SUMMARY/ABSTRACT: When we navigate a new environment, we have an internal understanding of where we are located in that environment. To build this internal sense of space, our brains integrate over time our estimate of how far we are walking and in which direction. I propose to study how brains integrate sensory information over time to form a working spatial memory. This question is pertinent to human health because impairments of spatial working memory are hallmarks of neurological and psychiatric disorders, like Alzheimer's disease and schizophrenia. A more detailed understanding of the mechanisms underlying spatial cognition should ultimately lead to more rational treatments for these conditions. I will study neural integration in the Drosophila central complex, an emerging model for spatial navigation that has notable similarities with the mammalian navigational system. Building on recent work that has characterized neural signals that track the direction and speed in which a fly travels, I will analyze central complex cells for processes that might integrate such signals into a working memory of a fly's position in space. The long-term objective of this project is to build a cellular- and circuit-level understanding of how neural signals are integrated over time to form working memories of spatial variables.