Basal forebrain lesioned mice exhibit deterioration in memory acquisition process in step through passive avoidance test.

Effects of the basal forebrain (BF) lesion on memory and learning performances were investigated in mice. Eight-week-old male mice received bilateral BF lesion by delivering a radiofrequency current. From fifteen days after the surgery, the step through type passive avoidance task was performed daily for 10 days. Lesioned animals showed severe impairment in the acquisition process of this task, but not in the retention process. Ambulatory activity of the BF-lesioned mice did not differ from those of the control group, suggesting the observed learning impairment was not due to the alteration of motor activity. These results indicate that a memory impaired model mice can be successfully made by the radiofrequency lesion of bilateral BF neurons.