Figure 3. Effects of chronic stimulation on the short- and long-term memory retention interval in the novel-object recognition test and Morris water-maze task.
Animals were tested in two different conditions with either no-HFS (A, B) or HFS (C, D) prior to the task. Effects of chronic stimulation on the memory performance in the Morris water-maze test (E, F). Note: VmPFC HFS significantly enhanced the short- and long-term memory performances in the novel-object recognition test (C, D). In the Morris water-maze experiment, there was an improvement on learning and memory after vmPFC HFS in both the training (E) and probe test (F) phases. Representative swimming paths (G) in the probe test, demonstrating vmPFC HFS increased duration within the virtual zone around the platform's location. Latency to reach the imaginary platform showed no difference between the vmPFC HFS and sham animals during the probe test (H). Indication: *, significant difference from the sham rats, (p < 0.05); #, significant from the familiar object of respective stimulation amplitude, (p < 0.05).