A pair of central brain peptidergic neurons modulates peripheral olfactory sensitivity to specific odors in Drosophila
Sion Yi, Walton D. Jones
Department of Biological Sciences, KAIST, Republic of Korea
Animals olfactory systems detect thousands of different environmental chemicals that are important in finding food and mates and in avoiding predators. Although the olfactory system detects a wide variety of chemical stimuli, it does not do so with equal sensitivity. Olfactory sensitivity can even modulated depending on internal and external cues so odor perception can be adapted to changing conditions. Here, we show knock-down of neuropeptide F (NPF) in a pair of central brain NPFergic neurons desensitizes Or22a-expressing antennal olfactory neurons. These neurons, which respond to ethyl butyrate, a volatile ester found in apples and other fruits, are similarly desensitized by knock-down of the NPF receptor, NPFR, in the Or22a neurons themselves. We also show that this phenomenon is very specific; cells in the same and adjacent olfactory sensilla are unaffected. NPF is reportedly down-regulated in various stress conditions (e.g., sexual-rejection and in the presence of parasitiod wasps). We are currently exploring the role NPF-mediated control over Or22a neuron sensitivity plays in directing stress-related behavioral shifts in food preference and other behaviors.
Key Words: olfaction, NPF, NPFR, OR22a