Fig. 3: Validating hippocampal dependency for performance in the two-object sPAL touchscreen task.

A sPAL visual stimuli (S+ rewarded, S− unrewarded). B Experimental sequence of hippocampal infusion study. Images show representative histological verification of cannula placement (left) and indicative sites of cannula tip placements across the group of mice tested (right). C Adult (12 W) male mice have trained on two-object sPAL over 8 testing sessions and showed rapid acquisition to 80% response accuracy. Animals subsequently underwent surgery to have bilateral infusion cannulae implanted into the dorsal hippocampus. Mice were given four reminder sessions (R1–R4) to reestablish pre-surgery performance levels. Data represent mean ± SEM, n = 11 male mice. Gray dotted line indicates performance at the chance (50% accuracy). D sPAL performance following dorsal hippocampal infusions with either (i) saline alone, (ii) MK-801 (NMDA receptor antagonist), or (iii) CNQX (AMPA/kainate receptor antagonist) + TTX (selective sodium channel blocker) or no infusion. Significant main effect of treatment, repeated measures ANOVA (F_{(3, 30)} = 48.51, P < 0.001). Post hoc Dunnett’s multiple comparisons test showed that compared to saline treatment, both CNQX (3 mM) + TTX (20 µM) (P < 0.001) or MK-801 (10 mM) (P < 0.001) significantly decreased performance accuracy. Performance following no infusion was not significantly different to saline treatment (P = 0.383). Data for individual mice are displayed together with mean ± SEM. ***P < 0.001 relative to saline. Gray dotted line indicates performance at the chance (50% accuracy).