Odor and shock response properties of dopaminergic processes in four subareas of the mushroom body lobes.
(A) General response properties shown from one
TH-GAL4>UAS-G-CaMP fly. Left, basal fluorescence. Middle, response to 0.1% methylcyclohexnol (MCH) presented to the antennae of the fly. Right, Response to 0.01 mA electric shock presented to the legs. All three images are averages of five successive frames either before (basal) or at the peak responses (MCH and shock). The tips of α lobe and α′ lobe were imaged simultaneously. MCH elicits a robust response in the PPL1 neuron processes that innervate the α′ tip and a much more modest response in those that innervate the

tip. Electric shock elicited a robust response in the processes that innervate the α tip and a much more modest response in those that innervate the α′ tip. PPL1 neurons therefore exhibit differential response properties to these stimuli.
(B) Group data. (Left panel) At the same current level, the response to electric shock was significantly higher in lower stalk/junction (
n = 12) and α tip (
n = 6) than in the α′ tip (
n = 6) or the upper stalk (
n = 12). The response increased in the lower stalk/junction with increasing current (
n = 12 at each current level). (Middle panel) Response to MCH was significantly higher in the tip of α′ (
n = 31) than in the tip of α (
n = 31), the upper stalk (
n = 45), or the lower stalk/junction (
n = 36). It was also significantly higher in the lower stalk/junction than in the α lobe tip. (Right panel) Responses in the upper stalk increased with increased odor concentration (
n = 7 for each point). Data points represent mean ± SEM. *Indicates significant difference (
p ≤ 0.0002). Each animal was subjected to only one stimulus at one dose to avoid complications due to prior exposure.