Fig. 4.

Cyclic-AMP elevation altered odor coding heterogeneously across single MB γ- and α/β-neurons. (A) Drawing of a frontal view of the MB, with the lobes and somata of α/β- and γ-neurons indicated with cyan and orange, respectively. (B) Horizontal confocal section of MB somata, expressing GCaMP6f under control of the γ-selective 1471-Gal4 driver. (C) Odor-evoked Ca²⁺ responses, before (pre) and after (post) cAMP elevation with forskolin, from the three neurons outlined in B. Ethyl butyrate was presented as the odorant. (D) Time series traces showing the responses of individual MB γ-neurons pre and post cAMP elevation. GCaMP was expressed under the γ-selective drivers 1471, R64C08, or MB009B, and traces from all three drivers are pooled here. (E) Magnitude of single-neuron, odor-evoked Ca²⁺ responses, pre and post forskolin application in MB γ-neurons (forskolin n = 292; saline n = 195). **P < 0.01, ***P < 0.001 (Sidak). (F) Change in odor-evoked Ca²⁺ responses among individual γ-neurons using three drivers: R64C08 (saline n = 75 neurons; forskolin n = 126), 1471 (saline n = 67; forskolin n = 95), or MB009B (saline n = 53; forskolin n = 71). **P < 0.01, ***P < 0.001 (Sidak). (G) Posttreatment Ca²⁺ response magnitude graphed against the pretreatment response in γ-neurons, comparing forskolin and saline groups. Arrows highlight selected neurons that exhibited decreases in odor-evoked responses, and linear regression lines are plotted. (H) Single-cell responses of γ-neurons, categorized by change in response following treatment (no change, increase, or decrease). (I) Time series traces showing the responses of individual MB α/β-neurons pre and post cAMP elevation. (J) Magnitude of single-neuron, odor-evoked Ca²⁺ responses, pre and post forskolin application in MB α/β-neurons. **P < 0.01, ***P < 0.001 (Sidak). (K) Change in odor-evoked Ca²⁺ responses among α/β-neurons using three drivers: c739 (saline n = 71 neurons; forskolin n = 84), R34B09 (saline n = 57; forskolin n = 91), and MB008B (saline n = 80; forskolin n = 85). **P < 0.01 (Sidak). (L) Posttreatment Ca²⁺ response magnitude graphed against the pretreatment response in α/β-neurons, plotted as in G. (M) Single-cell responses of α/β-neurons, plotted as in H.