SPLTRAK Abstract Submission
Glomerular Signals During Unrestrained Olfactory Search in Mice
Teresa Findley1, Ian Jackson1,2, Morgan Brown1, Blake Holcomb1, Nelly Nouboussi1, Roman Shusterman1, Jared Acosta-King1, David Wyrick1, Bishara Korkor1, Yashar Ahmadian1, Matt Smear1
1University of Oregon, Eugene, OR, United States
2Reed College, Portland, OR, United States

The olfactory system plays a principal role in search behaviors for many animals. However, the underlying computations of such search behaviors, especially under naturally turbulent conditions, are largely unknown. To investigate the behavioral structure of olfactory search in such turbulent conditions, our lab developed a behavioral assay for unrestrained mice. With this assay, we demonstrated that mice can reliably search up an odor concentration gradient that contains noise due to turbulence. Further, we found that mice develop sampling strategies for search involving head movement and fast sniffing. In order to understand the computational basis of these behaviors, we now strive to compare these sampling movements directly against sensory input during our search task. However, the unpredictability of air turbulence and the limitations of chemical sensor technology prevent accurate mapping of the olfactory scene. To overcome this challenge, we have developed a system that uses fiber photometry imaging of olfactory sensory neuron terminals in the glomerular layer of the olfactory bulb. Thus, we can capture activity at the first layer of sensory input to the brain in freely-moving mice. Using this technique, we not only overcome the challenge of detecting local odor concentration at the nose but incorporate perturbations from local turbulence, whisking, and sniffing. Our new behavioral assay accommodates fiber photometry recordings, electrophysiological recordings, and optogenetic manipulations. Measuring and manipulating sensory input during unrestrained olfactory search will offer novel insights into olfactory circuits and behavior.