Targeting Insect Olfaction in vivo and in vitro Using Functional Imaging

Fabio Miazzi; Kalpana Jain; Sabine Kaltofen; Jan E Bello; Bill S Hansson; Dieter Wicher

doi:10.3389/fncel.2022.839811

Targeting Insect Olfaction in vivo and in vitro Using Functional Imaging

Front Cell Neurosci. 2022 Feb 24:16:839811. doi: 10.3389/fncel.2022.839811. eCollection 2022.

Authors

Fabio Miazzi¹, Kalpana Jain¹, Sabine Kaltofen¹, Jan E Bello², Bill S Hansson¹, Dieter Wicher¹

Affiliations

¹ Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany.
² Department of Entomology, University of California, Riverside, Riverside, CA, United States.

Abstract

Insects decode volatile chemical signals from its surrounding environment with the help of its olfactory system, in a fast and reliable manner for its survival. In order to accomplish this task, odorant receptors (ORs) expressed in olfactory sensory neurons (OSNs) in the fly's antenna process such odor information. In order to study such a sophisticated process, we require access to the sensory neurons to perform functional imaging. In this article, we present different preparations to monitor odor information processing in Drosophila melanogaster OSNs using functional imaging of their Ca²⁺ dynamics. First, we established an in vivo preparation to image specific OSN population expressing the fluorescent Ca²⁺ reporter GCaMP3 during OR activation with airborne odors. Next, we developed a method to extract and to embed OSNs in a silica hydrogel with OR activation by dissolved odors. The odor response dynamics under these different conditions was qualitatively similar which indicates that the reduction of complexity did not affect the concentration dependence of odor responses at OSN level.

Keywords: Drosophila melanogaster; calcium imaging; insect olfaction; olfactory sensory neuron; silica hydrogel; waterglass.