Figure 3.

Focal homozygous gene deletion of Hdac3 in the dorsal hippocampus leads to enhanced memory for object location (OLM), which persists at least 7 d but not for object recognition (ORM). A, Mice received subthreshold training (3 min) in an environment with two identical objects and received a retention test 24 h or 7 d later in which one object is moved to a new location. Schematic describes methods for B and C. B, HDAC3^flox/flox mice exhibited significant long-term memory for object location 24 h after subthreshold training (n = 8 per group; **p < 0.005). C, In a different set of mice, the persistence of this enhanced memory was examined. HDAC3^flox/flox mice displayed a significant preference for the novel object location compared with HDAC3^+/+ mice during a 7 d retention test (n = 9 per group; **p < 0.001). D, Mice received subthreshold training (3 min) in an environment with two identical objects and received a retention test 24 h later in which one object is replaced with a novel one (ORM). Schematic describes methods for E. E, Neither HDAC3^+/+ or HDAC3^flox/flox mice exhibited significant preference for the novel object (n = 8 per group).