9421393 Puzdrowski All vertebrate animals possess a reflex response system that allows them to stabilize the eyes as the head is moved -- referred to as the vestibulo-ocular reflex (VOR). The brain circuits which control the reflex are similar throughout vertebrates with the exception that they are somewhat different in certain fishes (the "elasmobranchs"). With this award Dr. Rick Puzdrowski will conduct experiments to determine if the form of the elasmobranch VOR circuit is a unique specialization of that group, or instead is a fundamental circuit plan from which the circuits of all other vertebrates may have evolved. This will be accomplished by examining details of the anatomy and physiology of the VOR circuits in fish related to the elsamobranchs. The information provided by this research will give us important insights into how the fundamental operations of our brains were built-up during the course of evolution. ***