Need for Related Multipronged Approaches to Understand Olfactory Bulb Signal Processing

Recent work from our laboratory in awake behaving animals shows that olfactory bulb processing changes depending profoundly on behavioral context. Thus, we find that when recording from the olfactory bulb in a mouse during a go–no go association learning task, it is not unusual to find a mitral cell that initially does not respond to the rewarded or unrewarded odors but develops a differential response to the stimuli during the learning session. This places a challenge on how to approach understanding of olfactory bulb processing, because neural interactions differ depending on the status of the animal. Here we address the question of how the different approaches to study olfactory bulb neuron responses, including studies in anesthetized and unanesthetized animals in vivo and recordings in slices, complement each other. We conclude that more critical understanding of the relationship between the measurements in the different preparations is necessary for future advances in the understanding of olfactory bulb processing of odor information.