Figure 3.

Discrete Aversive Signals Use Common Reinforcing Dopaminergic Neurons

(A) Flies were differentially conditioned by pairing of one odor with electric shock of varying magnitude and the other odor with 0.4% DEET in sugar carrier. They were then immediately tested for olfactory preference. Flies avoided the odor that had been previously paired with 80 or 90 V but preferred the odor if it was paired with 30 or 60 V. Linear regression suggested that the intersecting point of equivalence between DEET and shock reinforcement was ∼70 V (R² = 0.68). n ≥ 8.

(B) Blockade of MP1 neurons did not alter the equivalent value of 0.4% DEET and 70 V. Flies trained with 70 V versus 0.4% DEET showed no learned odor preference. Performance of c061; MBGAL80; UAS-shi^ts1 flies with blocked MP1 neurons was indistinguishable from that of control groups (p > 0.6, ANOVA). None of the groups were statistically significant from zero (p > 0.1, one-sample t test, n ≥ 5).

(C) Blockade of MP1 neurons partially impaired aversive learning with 70 V. Performance of c061; MBGAL80; UAS-shi^ts1 flies was statistically different from that of control groups (p < 0.05, ANOVA, n ≥ 5).

Data are shown as mean ± SEM.