Neural Representations of Airflow in Drosophila Mushroom BodyAkira Mamiya1, Jennifer Beshel1, Chunsu Xu1,2, Yi Zhong1*1 Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America, 2 SUNY Stony Brook, Stony Brook, New York, United States of America

Take home points:

Goal: characterize the responses of MB neurons to changes in airflowMethod: In vivo calcium imaging from multiple MB regions using genetically altered fruit fly lines and 2-photon microscopyResults:

•Responses to an airflow stimulus from several sub regions of the MB•Different MB sub regions responded differently to different aspects (i.e. on/off responses)•Possibly sub sub regions respond differently•Dependent on the movement of the 3rd antennal segment suggesting JO involvement

Method1) Get TG fruitflies that have a calcium sensor

• UAS-G-CaMP1.3 • UAS-G-CaMP1.6

2) Cross with GAL4 fruit fly lines that will allow targeted expression of the calcium sensor in specific cells• OK107-Gal4: non-selective MB general• c739-Gal4: A/B lobe neurons• g0050-Gal4 and c305a-Gal4: A’/B’ lobe neurons

3) Fix fruit fly to an imaging stage4) Puff air and measure fluorescence:

• 3s stims • 100 ml/min (1.2m/s )• 3 min ITI

5) Analyses based on ΔF/Fo which is a measure of changes in Ca++ induced florescence on a pixel by pixel basis

Experimental recording sites and raw ΔF/Fo Figure 1

Temporal dynamics of responses 1 s data integration window (3 frames)Averaged results

Figure 2

Figure 2Mean On, off responses as a function of lobes

The total area involved in response

Figure 3

•OK107-Gal4: non-selective MB general•c739-Gal4: A/B lobe neurons•g0050-Gal4 and c305a-Gal4: A’/B’ lobe neurons

Different Gal4 lines show that A,B and A’B’ have different response profiles

Figure 4Responses generally depend on movement of the 3rd antennal segment•When glued Ca++ responses are greatly diminished

Figure 4

By comparison with Figure 2 most areas have dropped

Responses generally depend on movement of the 3rd antennal segment•When glued Ca++ responses are greatly diminished

Figure 5Sub region specific responses to “on” and “off” phases of the stimulus

Figure 5Watershed Segmentation highlights sub region specific responses

Figure 6“On Off Selectivity Index” (OSI) highlights watershed “patches” within lobes as “on” or “off” response selective (or neither)

Figure 7Off responding patches are spatially organized and stereotypic across individuals

Figure 8Using two Gal4 lines they show that the off and on responses are different subsets of cells

Figure 8

g0050-Gal4 cells are significantly more off responsive than c305a-Gal4