Gap junction coupling is neuron specific. Raw data of calcium imaging showing representative neuronal responses to stimuli in a period over 30 min. Data were binned every four frames after recordings using the Excel program and presented in the ratio of F340/F380. For the convenience of description, data are grouped into 5 phases. Duration of stimulation is indicated by black (for odorants) or red (for BGA) bars on the top. BEN, 100 μM benzaldehyde; BGA, 1 μM 18β-glycyrrhetinic acid, a gap junction uncoupling reagent; IBMX, 500 μM 3-isobutyl-1-methylxanthine; OCT, 100 μM octaldehyde.