Odor coding in the Drosophila antenna is examined by a functional analysis of individual olfactory receptor neurons (ORNs) in vivo. Sixteen distinct classes of ORNs, each with a unique response spectrum to a panel of 47 diverse odors, are identified by extracellular recordings. ORNs exhibit multiple modes of response dynamics: an individual neuron can show either excitatory or inhibitory responses, and can exhibit different modes of termination kinetics, when stimulated with different odors. The 16 ORN classes are combined in stereotyped configurations within seven functional types of basiconic sensilla. One sensillum type contains four ORNs and the others contain two neurons, combined according to a strict pairing rule. We provide a functional map of ORNs, showing that each ORN class is restricted to a particular spatial domain on the antennal surface.

We recently identified from the Drosophila genome database a large family of G protein-coupled receptor genes, the Gr genes, and predicted that they encode taste receptors on the basis of their structure and specificity of expression. The expression of Gr genes in gustatory neurons has subsequently been confirmed and 56 family members have been reported. Here we provide functional evidence that one Gr gene, Gr5a, encodes a taste receptor required for response to the sugar trehalose. In two different mutants that carry deletions in Gr5a, electrophysiological and behavioral responses to trehalose were diminished but the response to sucrose was unaffected. Transgenic rescue experiments showed that Gr5a confers response to trehalose. The results correlate a particular taste ligand with a Gr receptor and indicate a role for G protein-mediated signaling in the transduction of sweet taste in Drosophila.

Purpose To examine the extent to which communities participating in the Collective Impact Learning Collaborative (CILC) increased capacity to create conditions for collective impact (CI) to address racial disparities in maternal and child health (MCH) and align local efforts with state MCH priorities over a 12-month period. Description Eight communities participated in a learning collaborative that involved the provision of technical assistance via webinars, monthly team calls, and site visits to facilitate the development of a collective impact initiative. A Ready-Set-Go approach to technical assistance was used to guide the communities through each phase of development while also providing individual assistance to teams based on their capacity at the start of participation. Assessment A pre/post design measured change in capacity to engage in CI efforts over time. A survey designed to assess the completion of core tasks related to early indicators of CI was completed at baseline and 12 months later. Wilcoxon Signed Ranks Test and Mann-Whitney test determined statistically significant progress towards outcomes over 12 months and differences in progress between high-and low-capacity teams. Conclusion In 12 months, teams with little established groundwork made significant progress, in some ways exceeding progress of more established teams. Statistically significant progress was achieved in eleven of fourteen outcomes measured. Five teams aligned local efforts with state priorities after 12 months. Findings suggest technical assistance to establish conditions for collective impact can support progress even when pre-conditions for collective impact are not previously established.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.