Mapping of chemosensory neuron function to uncover changes in neuronal fates

Nervous systems evolve at the genetic, anatomical, and system levels. Our proposed research addresses both a fundamental question on how nervous systems with limited cell numbers evolve to accommodate new behavior, as well as answer specific questions on how the host-seeking infectious stage of nematodes remodel their chemosensory neurons at the gene expression level. We hypothesize that in the chemosensory neurons of the nematode Pristionchus pacificus, expansions in certain gustatory receptors can compensate for the lack of functional lateralization, while endocrine steroid hormones can modulate other chemosensory behavior according to developmental state of the neurons. We propose to map the functions of the chemosensory neurons by developing and using new genetic tools in targeted neuronal inactivation and in vivo calcium imaging, as well as to study how steroid hormone synthesis determine neuronal cell fate using genetic mutants.