Katherine Nagel

Katherine_NagelAssistant Professor, Department of Neuroscience & Physiology
NYU Neuroscience Institute

550 First Avenue
MSB 466B
New York, NY 10016

Phone: 646-501-4556
Fax: 646-501-4529
Email: katherine.nagel@nyumc.org

Research Summary:

Biophysics of sensory processing.

Our goal is to understand how the biophysical properties of cells and synapses shape the behavior of organisms in complex environments.  We study a simple organism (the fruitfly) that exhibits rich behavioral dynamics and offers many tools for looking at and interfering with neural function.  We use simple mathematical models to link observations at different levels of analysis.

We are currently pursuing two projects within this larger framework.  The first is to understand how flies combine cues from different sensory systems to navigate towards an odor source.  Odors in air form turbulent plumes in which the local odor concentration can fluctuate rapidly as a function of time.  Numerous behavioral studies have suggested that— due to the unpredictable dynamics of natural odors— insects navigate towards the source of an odor plume by combining odor information with mechanosensory or visual cues about wind direction.  Our lab is interested in several questions related to this behavior.  For example:  How do wind-guided turns depend on the history of odor encounters?  How do local behavioral algorithms depend on global statistical properties of odor and wind fluctuations?  Which neurons integrate odor information with wind and visual cues?  How does integration of sensory cues in individual neurons compare to behavioral integration of sensory cues by whole flies?  We are addressing these questions using behavioral paradigms and electrophysiological recordings from candidate cell lines.

Our second current project aims to understand how the temporal coding properties of a sensory circuit depend on the biophysical properties of synapses.  Chemical synapses exhibit dynamics on the time scale of tens of milliseconds to seconds that are collectively known as “short-term plasticity”.  Multiple mechanisms are thought to underlie these processes, such as accumulation of pre-synaptic calcium, pooling of neurotransmitter, depletion of synaptic vesicles, and inactivation of post-synaptic receptors.  Different forms of short-term plasticity are characteristic of particular synapses, and theorists have long appreciated that these processes have important consequences for how time-varying signals are transmitted across a synapse.  However, few experimental models allow for a direct comparison between the biophysical processes occurring at synapses and the in vivo responses of neurons embedded in a circuit.  We are using the Drosophila olfactory system as a model for understanding the relationship between synaptic processes and encoding of naturalistic time-varying stimuli.  We are interested in questions such as: which steps in synaptic transmission most strongly determine the temporal coding properties of downstream neurons?  How do changes in synaptic properties affect temporal coding in post-synaptic cells?  How are synaptic properties modified dynamically by circuit feedback and behavioral state?  What role do cell type-specific forms of short-term plasticity play in generating circuit output?  We are addressing these questions using a combination of electrophysiology, high-temporal resolution imaging, and pharmacological and genetic manipulations.

Selected Publications:

  • Nagel, K.I. and R.I. Wilson (2011) "Biophysical mechanisms underlying olfactory receptor neuron dynamics."  Nat. Neurosci. 14(2):208-16

  • Gaudry, Q., Nagel, K.I., and R.I. Wilson (2012)  “Smelling on the fly: sensory cues and strategies for olfactory navigation in Drosophila.”  Curr. Op.Neurobiol. 22(2):216-22.

  • Nagel, K.I., McLendon, H.M., and A.J. Doupe  (2010)  "Differential influence of frequency, timing, and intensity cues in a complex acoustic categorization task."  J. Neurophysiol.  104(3):1426-37

  • Nagel, K.I., and A.J. Doupe  (2008)  "Organizing Principles of Spectro-Temporal Encoding in the Avian Primary Auditory Area Field L"  Neuron, 58(6):938-955

  • Nagel, K.I., and A.J. Doupe  (2006)  "Temporal Processing and Adaptation in the Songbird Auditory Forebrain"  Neuron, 51(6):845-59