Research: How does the brain convert sensory stimuli into meaningful representations, and how do these representations drive behavioral responses?
Neural Mechanisms Underlying Social Communication in Flies
Despite the long history of courtship research in Drosophila, very little is known about the neural mechanisms underlying song patterning or perception. During courtship, male flies use their wings to produce patterned sound and woo a female into mating. Females are faced with the task of recognizing song, based on its species-specific parameters, and choosing a particular mate, based in part on differences in song between conspecific individuals. While flies do not learn their songs, their capacity to generate and respond to songs with so few neurons is striking, and suggests that studying flies will reveal insight into the basic requirements for communication.
Song Patterning and Production
In spite of its fundamental importance to communication, we know surprisingly little about how sensory cues modulate acoustic patterns in real time. We have recently demonstrated that, unlike most other insects and even some songbirds, flies sing highly variable songs (from one bout to the next, even within individuals). However, using a simple computational model combined with neural circuit manipulations, we demonstrated that the dynamic sensory experience of the male accounts for much of this variability. In particular, male flies rely on fast modulations in visual and self motion cues to pattern the structure of individual song bouts. The long-term objective of this line of research is to understand the cellular mechanisms by which time-varying sensory information is integrated into individual neurons of the song motor circuit. To do this, we combine quantitative behavioral assays, genetic and neural circuit perturbations, and in vivo neural recordings.
Song Processing and Perception
Neural tuning for species-specific acoustic signals is a conserved feature of auditory systems – it is found from insects all the way to humans. However, the precise mechanisms involved remain mysterious. We take advantage of the tools available in Drosophila to investigate, at the level of individual neurons and patterns of electrical activity, how such tuning arises and how it relates to behavioral decisions.
We record neural activity along the auditory pathway and in response to sounds (both natural and synthetic), starting with mechanosensory neurons in the antenna (or ear of the fly) all the way to central brain regions. Using computational modeling, we can discover how neural codes relate to behavioral preferences for song.
- Crocker, A, Guan, XJ, Murphy, CT, and Murthy, M. Cell Type-Specific Transcriptome Analysis in the Drosophila Mushroom Body Reveals Memory-Related Changes in Gene Expression. Cell Reports. 2016 May 17; 15, 1-17. doi: 10.1016/j.celrep.2016.04.046.
- Coen, P and Murthy, M. Singing on the Fly: Sensorimotor Integration and Acoustic Communication in Drosophila. Current Opinion in Neurobiology. 2016 Feb 10;38:38-45. doi: 10.1016/j.conb.2016.01.013.
- Coen, P, Xie, M, Clemens, J, and Murthy, M. Sensorimotor transformations underlying variability in song intensity during Drosophila courtship. Neuron. 2016 Feb 3; 89(3): 629-644.
- Clemens, J*, Girardin, C*, Coen, P, Guan, XJ, Dickson, BJ, and Murthy, M. Connecting neural codes with behavior in the auditory system of Drosophila. Neuron. 2015 Sep 23; 87:1-12. *equal authors
- LaRue, K, Clemens, J, Berman, GJ, and Murthy, M. Acoustic duetting in Drosophila virilis relies on the integration of auditory and tactile signals. eLife. 2015 June 5. doi: 10.7554/eLife.07277
- Coen, P, Clemens, J, Weinstein, A, Pacheco, D, Deng, Y, and Murthy, M. Dynamic sensory cues shape song structure in Drosophila. Nature. 2014 March 13. doi:10.1038/nature13131
- Arthur, BJ, Sunayama-Morita, T, Coen, P, Murthy, M* and Stern, DL*. Multi-channel acoustic recording and automated analysis of Drosophila courtship songs. BMC Biology 2013 January vol. 11(1): 11.
- *co-corresponding authors
- Tootoonian, S, Coen, P, Kawai, R, and Murthy, M. Neural representations of courtship song in the Drosophila brain. Journal of Neuroscience. 2012 January vol. 32(3): 787-798.
- Murthy, M. Unraveling the Auditory System of Drosophila. Current Opinion in Neurobiology. 2010 June 20(30): 281-287.
Honors and Awards
- 2011 NSF CAREER Award
- 2011 Human Frontiers Science Program Young Investigator Award
- 2011 Alfred P. Sloan Foundation Research Fellow
- 2012 Klingenstein-Simons Fellowship Award in the Neurosciences
- 2012 McKnight Foundation Scholar Award
- 2013- McDonnell Preceptor in Neuroscience, Princeton
- 2014 NIH New Innovator Award
- 2014 NSF BRAIN Initiative EAGER Award
- 2015 Princeton Dean’s Innovation Fund for New Ideas
- 2016 HHMI Faculty Scholar