Quantifying Multi-neuronal Olfactory Responses in C. elegans

Complex animal behaviors arise in response to an organism’s environment, as perceived through its senses. Unlike other stimuli animals experience, such as light or sound, chemosensory stimuli form a high dimensional space, making the computational problem faced by organisms interpreting olfactory cues especially complex. The processes by which olfactory information is encoded are poorly understood.
To better understand ensemble-level olfactory representation, we record from all sensory neurons in the nematode C. elegans simultaneously, while presenting stimuli in a highly controlled manner in a microfluidics environment. Observing the dynamics of these neurons in response to odors and odor mixtures of varying identity and strength has allowed us to build a quantitative and comprehensive picture of the way the olfactory system in C. elegans consolidates and represents high-dimensional sensory information. Our results suggest that olfactory stimuli are represented by distinct constellations of multiple chemosensory neurons, and that response characteristics of individual neurons is odor-dependent.