RT Journal Article SR Electronic T1 Multisite imaging of neural activity using a genetically encoded calcium sensor in the honey bee JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.04.22.489138 DO 10.1101/2022.04.22.489138 A1 Carcaud, Julie A1 Otte, Marianne A1 Grünewald, Bernd A1 Haase, Albrecht A1 Sandoz, Jean-Christophe A1 Beye, Martin YR 2022 UL http://biorxiv.org/content/early/2022/12/23/2022.04.22.489138.abstract AB Understanding of the neural bases for complex behaviors in Hymenoptera insect species has been limited by a lack of tools that allow measuring neuronal activity simultaneously in different brain regions. Here, we developed the first pan-neuronal genetic driver in a Hymenopteran model organism, the honey bee, and expressed the calcium indicator GCaMP6f under the control of the honey bee synapsin promoter. We show that GCaMP6f is widely expressed in the honey bee brain, allowing to record neural activity from multiple brain regions. To assess the power of this tool, we focused on the olfactory system, recording simultaneous responses from the antennal lobe, and from the more poorly investigated lateral horn and mushroom body calyces. Neural responses to 16 distinct odorants demonstrate that odorant quality (chemical structure) and quantity are faithfully encoded in the honey bee antennal lobe. In contrast, odor coding in the lateral horn departs from this simple physico-chemical coding, supporting the role of this structure in coding the biological value of odorants. We further demonstrate robust neural responses to several bee pheromone odorants, key drivers of social behavior, in the lateral horn. Combined, these brain recordings represent the first use of a neurogenetic tool for recording large-scale neural activity in a eusocial insect, and will be of utility in assessing the neural underpinnings of olfactory and other sensory modalities and of social behaviors and cognitive abilities.Competing Interest StatementThe authors have declared no competing interest.