A major goal for neuroscience is to understand how information processing in neural circuits guides animal behaviour. At any given moment, the brain receives a rich set of sensory inputs, from both external and internal sources.
This information must be integrated, interpreted in the light of knowledge gained through prior experience, and a specific behavioural action selected. These processes of sensory integration, learning and memory, decision making, and action selection are the essence of animal cognition and behaviour. Our goal is to provide a biophysical explanation for these processes.
As a model, we have chosen to study the sex life of the fruit fly Drosophila melanogaster. During mating, flies make decisions that are critical for their reproductive success, and hence their evolutionary fitness. Upon encountering another fly, a male decides whether or not to court, based on the current sensory input and his past experience. If he does court, the female then decides whether to accept or reject him, based on her perception of his quality as a potential mate, and her own sexual maturity and mating status. These are complex decisions made by complex brains, but working with flies has the great advantage that genetic tools can be used to identify and manipulate the relevant neurons and circuits in the brain. With these tools, it should be possible to establish causal relationships between genes, cellular biochemistry, circuit function, and animal behaviour.