Fig. 2.

Systemic MTEP but not MK-801 reduced CS port entries. a We tested the expression of CS port entries in well-trained rats (n = 17) following systemic injections of vehicle, 0.1 mg/kg MK-801, or 5 mg/kg MTEP in a counterbalanced, within-subjects design. Normalized CS port entries (CS–Pre-CS port entries) were elevated in the sugar context relative to the neutral context, and reduced following MTEP, but not MK-801, in both contexts. b The first CS port entry took longer to occur in both contexts following MTEP, but not MK-801. c MTEP had no effect on port entries during the ITI. d In the sugar context, non-normalized CS port entries were significantly reduced by MTEP in the first half of the session, beginning in the second CS trial. e In the neutral context, MTEP reduced CS port entries in the first half of the session, but beginning on the first trial. Data are presented as means ± SEM. *p < 0.05 Bonferroni post-hoc comparisons for MTEP compared to vehicle and MK-801. ^p < 0.05 Bonferroni post-hoc comparisons for MTEP compared to MK-801. Statistical tests were repeated measures ANOVAs. Data from individual rats are depicted as gray dots (a–c)