LONG RANGE OBJECTIVES To develop products that enhance research methods and applications in animal research using magnetic resonance imaging to study mental illness. PHASE I The planar gradient coil, or PROTOTYPE we propose to develop will optimize the working area inside MR spectrometers expanding the experimental applications and the types of animals that can be studied in small bore ultra-high field magnets. This PROTOTYPE would be an innovative advance in gradient coil design that could substitute for the conventional cylindrical gradient coils that appreciably reduce the working area in the magnet. The specific aims are: (1) Simulate the magnetic field homogeneity and linearity for different wire patterns and planar dimensions using numerical modeling programs, (2) Based on the simulation data, design, construct and bench test the electrical performance of the PROTOTYPE, and (3) Test the performance of the PROTOTYPE in a monkey functional imaging study. HEALTH RELATEDNESS Using non-invasive MRI in various animal species, particularly monkeys to study brain development and function will make it possible to: (1) design prospective studies to understand the etiology and pathophysiology of mental illness, and (2) evaluate the site of action and efficacy of new drugs developed for the treatment of mental illness. PROPOSED COMMERCIAL APPLICATION: Research in the field of ultra-high field MRI for animal research is growing tremendously. Last year alone, there were over 1000 papers published in this area of science. The technological innovations proposed by INSL are expected to expand the methods and applications of MRI in the study of mental illness in animal models.