Connecting Neural Codes with Behavior in the Auditory System of Drosophila

Abstract

SummaryBrains are optimized for processing ethologically relevant sensory signals. However, few studies have characterized the neural coding mechanisms that underlie the transformation from natural sensory information to behavior. Here, we focus on acoustic communication in Drosophila melanogaster, and use computational modeling to link natural courtship song, neuronal codes, and female behavioral responses to song. We show that melanogaster females are sensitive to long timescale song structure (on the order of tens of seconds). From intracellular recordings, we generate models that recapitulate neural responses to acoustic stimuli. We link these neural codes with female behavior by generating model neural responses to natural courtship song. Using a simple decoder, we predict female behavioral responses to the same song stimuli with high accuracy. Our modeling approach reveals how long timescale song features are represented by the Drosophila brain, and how neural representations can be decoded to generate behavioral selectivity for acoustic communication signals.

Fast Intensity Adaptation Enhances the Encoding of Sound inDrosophila

“…1f, Supplementary 1e), suggesting the recorded CAP 7 is dominated by activity from type AB JONs and that adaptation is a property of this subpopulation. This 8 result is consistent with previous reports that show that the activity of type AB JONs, but not of type CE 9 JONs, is visible in the CAP for the frequency and intensity range of stimuli used in our study 11,21,24 . 10 Second, extracellular signals, such as cortical LFPs, can be sensitive to the synchrony among neurons in 11 the population 27 .…”

“…2a, top). On a 8 linear intensity scale, the slope of the tuning curves decreases with background intensity, indicating that 9 variance adaptation is indeed divisive. A logarithmic intensity scale, which transforms this division to a 10 rightward shift of the tuning curves, reveals a) that tuning curve shape is invariant to intensity (Fig.…”

“…1a, bottom) and can saturate the responses to sound since mechanotransduction 8 works only over a limited displacement range 18 . 9 Thus, the Drosophila auditory system requires a neuronal mechanism for adaptation to both fluctuations 10 in the baseline of antennal displacements and the intensity of the acoustic signal. While a subtractive 11 mean adaptation mechanism corrects for the displacement baseline 18,19 , no studies have yet examined 12 variance adaptation in Drosophila.…”

Active Mechanisms of Vibration Encoding and Frequency Filtering in Central Mechanosensory Neurons

“…Indeed, B1 cells are the only cells in the Drosophila brain which are known to be bandpass-tuned to antennal vibrations. All other cell types seems to be lowpass-tuned (Clemens et al, 2015; Tootoonian et al, 2012). …”

“…Recently, new genetic tools have made it possible to target identified mechanosensory neurons of the Drosophila central nervous system for in vivo intracellular recording (Chang et al, 2016; Clemens et al, 2015; Lehnert et al, 2013; Tootoonian et al, 2012; Tuthill and Wilson, 2016). This approach provides the opportunity to connect neural computations in mechanosensory systems with the cellular mechanisms that implement those computations.…”