Fig. 6.
Phasic dopamine release develops to the CS and persists to the US during Pavlovian conditioning in control and NR1-KO mice. (A) US-evoked dopamine responses were decreased in NR1-KO (n = 5) compared with control (n = 6) mice across all seven training sessions [mean area under the curve (AUC) ± SEM, two-way ANOVA, control vs. NR1-KO; F(1,9) = 10.8; ##P < 0.01]. dopamine release at the time of reward retrieval rather than delivery was used for session 1. (B) CS-evoked dopamine responses were decreased in NR1-KO mice but increased significantly during training in both groups (mean AUC ± SEM, two-way ANOVA, genotype x session; F(6,54) = 3.4; ##P < 0.01; Fisher post hoc analysis; *P < 0.05; **P < 0.01; ***P < 0.001). (C) CA scores increased similarly in the control and NR1-KO mice used in the FSCV experiment (mean ± SEM). (D) Average dopamine traces form control and NR1-KO mice in response to CS and US presentations on days 1, 2, and 7. Inset shows mean dopamine traces at the time of reward retrieval during session 1. (E and F) Three-dimensional representations summarize the phasic dopamine release to the CS and US for control (E) and NR1-KO (F) across all training days (five-trial blocks).