Active sensing in a dynamic olfactory world

© The Author(s) 2021. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.This Perspective highlights the shift from the classic picture of olfaction as slow and static to a view in which dynamics play a critical role at many levels of sensing and behavior. Olfaction is now increasingly seen as a “wide-bandwidth temporal sense” (Ackels et al., 2021; Nagel et al., 2015). A parallel transition is occurring in odor-guided robot navigation, where it has been discovered that sensors can access temporal cues useful for navigation (Schmuker et al., 2016). We are only beginning to understand the implications of this paradigm-shift on our view of olfactory and olfactomotor circuits. Below we review insights into the information encoded in turbulent odor plumes and shine light on how animals could access this information. We suggest that a key challenge for olfactory neuroscience is to re-interpret work based on static stimuli in the context of natural odor dynamics and actively exploring animals.Peer reviewedFinal Published versio

Active spreading: Hydraulics for enhancing groundwater remediation

During in situ groundwater remediation, reactions occur in a narrow reaction front in which the amendment and contaminant are close enough to mix. Active spreading, in which injection or extraction wells create spatially variable velocity fields, can be used to increase the surface area of the reaction front, thereby enhancing reaction. This study used four active spreading flow fields that are building blocks to more complex remediation hydraulics to evaluate how the flow field and the plume position control contaminant degradation in both homogeneous and heterogeneous aquifers. At the plume scale, reaction depended on mechanical dispersion across the reaction front, which is proportional to both the local velocity and the local contaminant concentration gradient. Mechanical dispersion and, consequently, the amount of degradation, was highest when the reaction front was perpendicular to the local velocity, producing a high local dispersion coefficient. This effect was amplified where flow was diverging due to sharpening of the concentration gradient. &nbsp;</p

Elementary sensory-motor transformations underlying olfactory navigation in walking fruit-flies.

Odor attraction in walking Drosophila melanogaster is commonly used to relate neural function to behavior, but the algorithms underlying attraction are unclear. Here, we develop a high-throughput assay to measure olfactory behavior in response to well-controlled sensory stimuli. We show that odor evokes two behaviors: an upwind run during odor (ON response), and a local search at odor offset (OFF response). Wind orientation requires antennal mechanoreceptors, but search is driven solely by odor. Using dynamic odor stimuli, we measure the dependence of these two behaviors on odor intensity and history. Based on these data, we develop a navigation model that recapitulates the behavior of flies in our apparatus, and generates realistic trajectories when run in a turbulent boundary layer plume. The ability to parse olfactory navigation into quantifiable elementary sensori-motor transformations provides a foundation for dissecting neural circuits that govern olfactory behavior

Cortactin phosphorylation regulates cell invasion through a pH-dependent pathway

Cortactin phosphorylation induces recruitment of the sodium-hydrogen exchanger NHE1 to invadopodia, resulting in pH changes that regulate cortactin-cofilin binding and invadopodium dynamics

O2A Network HDF5 Odor Plume Datasets

The Odor2Action Network HDF5 Odor Plume Data Package contains two datasets (air and water) along with detailed metadata. These data were acquired using the planar laser-induced fluorescence (PLIF) technique, and consist of time stacks of 2D grayscale images. Funding: NSF IdeasLab PHY 1555862; NSF NeuroNex DBI 2014217. Data will be made publicly available here when ready

Odor landscapes and animal behavior: tracking odor plumes in different physical worlds

Abstract The acquisition of information from sensory systems is critical in mediating many ecological interactions. Chemosensory signals are predominantly used as sources of information about habitats and other organisms in aquatic environments. The movement and distribution of chemical signals within an environment is heavily dependent upon the physics that dominate at different size scales. In this paper, we review the physical constraints on the dispersion of chemical signals and show how those constraints are size-dependent phenomenon. In addition, we review some of the morphological and behavioral adaptations that aquatic animals possess which allow them to effectively extract ecological information from chemical signals.

Odor2Action

The Odor2Action network brings together international scientists to solve classic, unresolved questions in neuroscience. Using the olfactory circuit, we aim to achieve an end-to-end understanding of how brains organize and process information from odors to guide adaptive behaviors. Through highly synergistic and inclusive team science, Odor2Action strives to create a model of open data and technology sharing that accelerates discoveries across the scientific community

Data

This is the landing page for all data from the Odor2Action network

Software

This is the landing page for all software from the Odor2Action network

Appendix G. Peat surface topography across two ridge/slough transects in the best-preserved portion of the ridge and slough landscape in WCA-3A.

Peat surface topography across two ridge/slough transects in the best-preserved portion of the ridge and slough landscape in WCA-3A