A candidate electromagnetic channel for coordination between physicallyseparated Drosophila

Abstract

While filming Drosophila melanogaster recovering together from xenon anesthesia, we noticed frequent synchronous pauses in flies recovering in the same chamber. To ask whether such coordination could survive physical separation of the animals, we housed flies individually in the opaque wells of a multi-well plate, with no visual or tactile contact. They still coordinated the magnitude of their movements around a shared light*dark startle more closely than the shared stimulus alone can explain. We isolate this excess coordination with a measure that subtracts the stimulus-driven component by comparing movements within versus across transitions. A complementary common-mode statistic shows that flies also remain weakly but reproducibly correlated away from the transitions. The tested conventional channels do not readily account for the effect: vision is excluded by the opaque walls, and self-generated substrate vibration is disfavored for the background common mode because coordination does not scale with movement amplitude and persists when the continuous side-wall path between wells is interrupted by air gaps. The transition signal declined across the material series from plastic toward aluminum. This paNern is not a simple metal-versus-nonmetal split. It is consistent with material-dependent near-field magnetic radiofrequency coupling through the well geometry and transparent imaging aperture. Vector-network measurements also indicate that near-field inter- well coupling differs between steel and aluminum. We have previously shown that Drosophila emit spontaneous, metabolically powered magnetic radiofrequency radiation that tracks nervous-system activity. Together these results are consistent with a near-field magnetic emission that can leak between separated individuals. We discuss radical-pair detection, possible emission mechanisms, and experiments needed to identify the carrier frequency, detector, and biological role. SignificanceFruit flies housed in separate, opaque chambers that block sight and touch nonetheless coordinate their movements. The coordination persists when mechanical vibration paths between chambers are cut. The coordination is absent when the plate is made of aluminum, and intermediate in size when the plate is made of ferromagnetic steel. This ordering, together with direct RF-coupling measurements, points to a near-field magnetic radiofrequency signal passing between individuals, though the carrier frequency and detector remain unknown. Because flies are already known to emit faint, metabolically powered radiofrequency fields that track nervous-system activity, these results raise the possibility that nervous systems both emit and detect such fields. If confirmed, this would identify an unrecognized magnetic radiofrequency channel in animal biology and suggest that brains are less electromagnetically private than assumed.