Drosophila social clustering is disrupted by anesthetics and in narrow abdomen ion channel mutants

Abstract

Members of many species tend to congregate, a behavioral strategy known as local enhancement. Selective advantages of local enhancement range from efficient use of resources to defense from predators. While previous studies have examined many types of social behavior in fruit flies, few have specifically investigated local enhancement. Resource-independent local enhancement has recently been described in the fruit fly using a measure called social space index, although the neural mechanisms remain unknown. Here we analyze resource-independent local enhancement of Drosophila under conditions that allow us to elucidate its neural mechanisms. We have investigated the effects of general volatile anesthetics, compounds that compromise higher order functioning of the type typically required for responding to social cues. We exposed Canton-S flies to non-immobilizing concentrations of halothane and found that flies had a significantly decreased social space index compared to flies tested in air. Narrow abdomen (na) mutants, which display altered responses to anesthetics in numerous behavioral assays, also have a significantly reduced social space index, an effect that was fully reversed by restoring expression of na by driving a UAS-NA rescue construct with NA-GAL4. We found that na expression in cholinergic neurons fully rescued the behavioral defect, whereas expression of na in glutamatergic neurons did so only partially. Our results also suggest a role for na expression in the mushroom bodies, since suppressing na expression in the mushroom bodies of NA-GAL4 rescue flies diminishes social space index. Our data indicate that resource-independent local enhancement, a simple behavioral strategy, requires complex neural processing.

Effect of bisphenol A on Drosophila melanogaster behavior – A new model for the studies on neurodevelopmental disorders

“…Thus, interaction between flies follows a non-random pattern [77]. In our study, inter-fly distance was used as a measure for social interaction [52,53,78,79], and we found that when the flies exposed to BPA were placed in a social setting, there was a decrease in the inter-fly distance. This decrease may be due to aberrant social interaction, in which the flies do not maintain the ideal balance of attraction/repulsion and interact inappropriately with each other.…”

“…The distance between an individual fly and its closest neighboring flies was used as a measure of social interaction within the group, as previously described [50,52,53]. In a social setting, most Canton-S wild-type flies maintain at least a two body length distance from their closest neighbor (∼0.25 cm) [54].…”

Drosophilamutants of the autism candidategene neurobeachin(rugose) exhibit neuro-developmental disorders, aberrant synaptic properties, altered locomotion, and impaired adult social behavior and activity patterns

“…We first tested the ability of the flies to avoid the Drosophila stress odorant (dSO) left by agitated flies in the avoidance assay (Suh et al, 2004; Fernandez et al, 2014). We also tested the flies’ response to others in social clustering, the measure of distances to their closest neighbor (their social space), in a stable undisturbed group (Burg et al, 2013; Simon et al, 2012). Social space and social avoidance probably result from equilibrium between multiple attractive and repulsive cues (reviewed in Mogilner et al, 2003), in addition to environmental factors.…”

“…This time delay does not affect social space in CS flies (Simon et al, 2012). Digital images were imported in ImageJ software (NIH, rsbweb.nih.gov/ij) and analyzed for nearest neighbor distances as described in (Burg et al, 2013). These data were imported into GraphPad Prism 6 for further analysis.…”

“…These data were imported into GraphPad Prism 6 for further analysis. Instead of using the previously reported Social Space Index, which is an indirect representation of the data (Burg et al, 2013; Simon et al, 2012), we choose here to directly represent the distribution of the distances using boxes and Tukey’s whiskers plots, as a statistical tool to eliminate outliers. Because the distribution of the distance was non-Gaussian, statistical analyses were performed using Kruskal-Wallis tests and Dunn’s multiple comparisons post-tests.…”