Effect of neural transplantation on depressive behavior in rats with lesioned nucleus basalis magnocellularis

Recent data of our group have shown that bilateral electrolytic lesions of the nucleus basalis magnocellularis (NBM) in rats reduced the escape behavior deficit that occurs in the learned helplessness test. The present study was done to establish the effect of intracerebral neural transplantation on the change in escape behavior of NBM-lesioned adult male Wistar rats in the learned helplessness test. At 2 days (NBM-ET) or 10 days (NBM-DT) after bilateral electrolytic NBM-lesions, small fragments of fetal frontal cortex (18th day of gestation) were allotransplanted into the lesioned NBM. Ten days after neural transplantation, the learned helplessness test was performed. The number of shocks that animals received before making an escape response was significantly reduced in NBM-lesioned rats (p < .001, compared to intact control and sham-operated rats). In comparison to NBM-lesioned and sham-ET rats, the NBM-ET rats showed a marked (p < .001) increase in the number of shocks delivered before the animal made such an escape response. On the other hand, NBM-DT rats did not show this increase. These results indicate that neural transplantation performed at an early time after lesioning of NBM reversed the effect of this lesion in rats exposed to learned helplessness test.