Fig. 2.
Experimental design for pre-training CNO injections using the object placement (A) and object recognition tasks (B). (C) In the object placement task, DH sham and eGFP control mice administered 2 mg/kg CNO 30 min before training spent significantly more time than chance (15 s) with the moved object 4 h after training, whereas DH-hM4Di-expressing mice administered 2 mg/kg CNO did not. (D) In the object recognition task, DH Sham, eGFP, and hM4Di mice administered 2 mg/kg CNO 30 min prior to training all spent significantly more time than chance (15 s) with the novel object during testing, suggesting intact object recognition memory 24 h after training. These findings suggest that pre-training hM4Di-mediated inactivation of the DH impairs spatial, but not object recognition, memory formation. Bars represent the mean ± SEM, *p < 0.05 relative to chance or the Control group.