[Improvement of memory by post-experiment BALB/c mouse lateral hypothalamus stimulation]

In order to test the influence of a post-trial low level rewarding stimulation on learning, BALB/c mice were bilaterally implanted in the lateral hypothalamus. First, all the animals were submitted to a 15 mn appetitive learning session in a Skinner Box (CRF). 30 s later, animals of the experimental group were stimulated for 80 s (100 Hz sinusoidal current; 200 ms ON/200 ms OFF; 10 muA/electrode). 24 h later the performances of the stimulated animals were compared to those of non-stimulated or not implanted animals. An improvement of reminiscence effect was observed in stimulated animals. Second, the self-stimulation behavior was studied in stimulated subjects; at 10 muA, this behavior was effective in all animals. The results are interpreted as revealing the involvement of the rewarding system in memory processes.