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| Poster #270 Behaviorally relevant features of the neural code in olfactory bulb |
| Saeed Karimimehr1,2, Sebastian Ceballo1, Mursel Karadas1, Dmitry Rinberg1,2,3 1Neuroscience Institute, New York University Langone Health, New York, NY, United States 2Center for Neural Science, New York University, New York, NY, United States 3Department of Physics, New York University, New York, NY, United States |
Odor stimuli evoke spatiotemporal patterns of activity at the glomerular level in the olfactory bulb. The relationship between patterns of neural activity and perceptual similarities among sensory stimuli remains debatable. In this study, we designed an experiment using the 2-alternative-forced-choice (2AFC) paradigm to measure the generalization ability of mice in precise odor discriminations. This task allowed us to smoothly vary the spatiotemporal patterns of activity using three-component odor mixtures to identify the relevant features of neural activity that drive behavioral discriminations. We trained mice to discriminate a specific mixture of three odors (referred to as the "Target") from a range of different odor stimuli (referred to as "Non-Targets"). In subsequent probe trials, we manipulated the mixture's composition to test the mice's ability to generalize their response. We then employed two-photon Ca2+ imaging to measure the neural activity in glomeruli in mice expressing the fast calcium indicators in olfactory sensory neurons. Based on these recordings, we developed a model to identify the critical features of neural activity that influence behavior. Our analysis suggests that the most relevant glomeruli are activated within the early temporal window of the sniff cycle. The weight of the relevant glomeruli in the model decays over the temporal window of the sniff cycle, and not all glomeruli active during this early phase are behaviorally relevant. Furthermore, we showed these observations are generalizable across diverse odor sets. These findings provide valuable insights into how the olfactory system represents and distinguishes between odor mixtures, highlighting the importance of the order of neural activity and the significance of temporal dynamics in encoding these mixtures. |