IBN-9813431 LAY Abstract Greenspan Innate behavior, such as courtship in the fruit fly, Drosophila melanogaster, is subject to a high degree of genetic control. But some aspects of it are also modifiable through learning. What a male fly learns during courtship is not to waste his time on a female who has already mated and who will consequently not be receptive to him. An enzyme in nerve cells known as the calcium/calmodulin-dependent protein kinase (CaM kinase II) is thought to play an important role in learning and memory. The Investigators have developed techniques to alter the activity of this enzyme in vivo and will carry out studies to define what parts of the brain are involved in this example of learned behavior.