View Program - 63rd Annual Drosophila Research Conference

The patterns of neuronal connectivity determined by development generate much of the computational power of the central nervous system. In brain regions devoted to sensory processing, sparse, combinatorial connectivity expands perceptual capacity. In the Drosophila mushroom body, sparse combinatorial connectivity between projection neurons carrying olfactory information from the periphery and Kenyon cells results in separable coding of many diverse scents and thus underlies successful associative learning. Each Kenyon cell (KC) receives input from a handful of projection neuron (PN) types through claw- like dendrites which each enwrap a single projection neuron bouton. Our lab has demonstrated that Kenyon cells determine connectivity density through the number of claws they produce, which are invariant when KC population is increased or reduced. Rather, PN bouton number changes to accommodate the changes in postsynaptic KCs. Here, we ask how the combinations of PN inputs to KCs are determined. Two possible sources of variation in projection neurons connections to Kenyon cells are molecular and spatial variation. By describing levels of transcriptional variation among projection neurons and Kenyon cells and the spatial relationships among these cells in connectomic data, we are testing the relative importance of these factors. Insights into the development of the mushroom body calyx will add to the existing knowledge of the diverse ways in which neuronal connectivity is controlled during development to produce functional circuits.

Promiscuous wiring via variable spatial sampling of an orderly array