title: Neural representations of courtship song in the Drosophila brain.
abstract: Acoustic communication in drosophilid flies is based on the production and perception of courtship songs, which facilitate mating. Despite decades of research on courtship songs and behavior in Drosophila, central auditory responses have remained uncharacterized. In this study, we report on intracellular recordings from central neurons that innervate the Drosophila antennal mechanosensory and motor center (AMMC), the first relay for auditory information in the fly brain. These neurons produce graded-potential (nonspiking) responses to sound; we compare recordings from AMMC neurons to extracellular recordings of the receptor neuron population [Johnston's organ neurons (JONs)]. We discover that, while steady-state response profiles for tonal and broadband stimuli are significantly transformed between the JON population in the antenna and AMMC neurons in the brain, transient responses to pulses present in natural stimuli (courtship song) are not. For pulse stimuli in particular, AMMC neurons simply low-pass filter the receptor population response, thus preserving low-frequency temporal features (such as the spacing of song pulses) for analysis by postsynaptic neurons. We also compare responses in two closely related Drosophila species, Drosophila melanogaster and Drosophila simulans, and find that pulse song responses are largely similar, despite differences in the spectral content of their songs. Our recordings inform how downstream circuits may read out behaviorally relevant information from central neurons in the AMMC.
authors.affiliation: Computation and Neural Systems Program and Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: Sina
authors.initials: S
authors.lastname: Tootoonian
authors.forename: Philip
authors.initials: P
authors.lastname: Coen
authors.forename: Risa
authors.initials: R
authors.lastname: Kawai
authors.forename: Mala
authors.initials: M
authors.lastname: Murthy
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000162:Acoustics; D000200:Action Potentials / Q000235:genetics / Q000502:physiology; D000819:Animal Communication; D000818:Animals; D030801:Animals, Genetically Modified; D001306:Auditory Pathways / Q000502:physiology; D001307:Auditory Perception; D001703:Biophysics; D001921:Brain / Q000166:cytology* / Q000502:physiology; D003380:Courtship; D004330:Drosophila; D029721:Drosophila Proteins; D004558:Electric Stimulation; D005260:Female; D005583:Fourier Analysis; D049452:Green Fluorescent Proteins / Q000235:genetics; D008297:Male; D018408:Patch-Clamp Techniques; D011930:Reaction Time; D012679:Sense Organs / Q000166:cytology / Q000502:physiology; D011984:Sensory Receptor Cells / Q000502:physiology*; D013016:Sound; D013018:Sound Spectrography
chemical_list: D029721:Drosophila Proteins; D049452:Green Fluorescent Proteins