GOAL: A major goal in neuroscience is to understand how neural circuits represent sensory information or guide behavior. Because of the complexity of our nervous system it is often difficult to pinpoint the neurons that participate in a given task. Our overall aim is to map out “complete circuits” underlying simple and complex behaviors and understand neural computations with the complete circuit in hand.
APPROACH: We will focus on the relatively simple brain of Drosophila to attack this problem. The fly’s brain can perform a surprisingly diverse array of behaviors with relatively few neurons (~100000). In particular, the olfactory circuit of Drosophila is uniquely suited for studying this question because its anatomical organization makes it possible to quantify the pool of neurons activated by a given stimulus. This anatomical simplification occurs because for each odorant receptor gene (there are ~50 in flies), there is an identifiable first-order neuron (ORN) and an identifiable second-order neuron (PN). We have a nearly complete picture of odor representation at the level of olfactory receptor neurons. Basic principles underlying the transformation of odor responses from ORNs-to-PNs are also understood. Because of this groundwork, odors (stimuli) can readily be mapped onto patterns of ORNs and PNs.
TOOLS: We use single-cell recordings from neurons in the fly brain to understand neural computations. We have also developed behavioral paradigms to make quantitative assessment of flies’ behavioral output. We will complement these relatively new techniques with molecular genetics in the fly.