Post-training medial septal stimulation improves spatial information processing in BALB/c mice

Abstract The experiment reported here was designed to highlight the effects of medial septal nucleus electrical stimulation on memory processes. To that end, we have used a learning task carried out in a 4-hole board in which animals were successively presented with the location of 2 baited holes. Under these conditions, the consequence of a weak stimulation (30 μA peak to peak, 80 s in duration) applied 30 s after acquisition of these 2 separate spatial informations was assessed on a retention test 24 h later. The results indicated that performance of stimulated animals was improved by medial septal stimulation as shown by an increase in the time duration of exploration of the second previously baited hole. However, post-training stimulation also produced a significant avoidance of the first previously baited hole not observed in the control groups. These results suggest that medial septal stimulation improves retroactive inhibition involved in working memory processes, thus leading to better retention of this kind of learning situation.