It has long been hypothesized that active sampling in the olfactory system-sniffing-plays a critical role in the processing of odor information. Though sniffing occurs in bouts lasting up to several seconds and containing dozens of individual sniffs, most work addressing the importance of this phenomenon has focused on the first sniff. This proposal expands upon previous work and considers the importance of the entire sniffing bout as it relates to the processing of odors. Three functional hypotheses about the importance of sniffing are examined by analyzing optical signals of olfactory bulb activity in anesthetized and awake mice that are being presented with various odors across a range of sniffing frequencies. Specific attention is paid to how early principal neurons of the olfactory circuit, olfactory sensory neurons and mitral cells, are differentially modulated by sniffing, and how processing by these cells contributes to information coding. Whereas most work on information processing by the olfactory bulb considers mono-molecular odorants, in this project complex mixtures are examined, owing to their importance in the natural environment. By incorporating behaviorally relevant sampling strategies and odor stimuli, the proposed experiments will provide insight into how the initial processing stages of the olfactory system incorporate sniffing-related dynamics to encode odor information.
The ways in which an animal actively senses its environment determine to a large extent how the brain perceives the natural world. Using newly-developed genetic and optical tools, this project will characterize how active sensation in the olfactory system enables animals to translate smells into useful information used by higher centers of the brain. Understanding how active sensation contributes to odor perception and odor- guided behaviors could lead to a greater understanding of olfactory deficits that result from injury or disease and point towards novel therapeutic approaches.
| Eiting, Thomas P; Wachowiak, Matt (2018) Artificial Inhalation Protocol in Adult Mice. Bio Protoc 8: |
