Effect of physostigmine and verapamil on active avoidance in an experimental model of Alzheimer's disease

The present study was performed to investigate and compare the effect of acetylcholinesterase inhibitor, physostigmine (0.045, 0.060 and 0.075 mg/kg sc, 30 min before the tests) and Ca-antagonist, verapamil (1.0, 2.5, 5.0 and 10.0 mg/kg sc, 30 min before the tests), on two-way active avoidance (AA) learning (acquisition and performance) in nucleus basalis magnocellularis (NBM)-lesioned rats. Bilateral electrolytic lesions of NBM induced significant decrease of acquisition and performance of AA responses in rats. Physostigmine (0.060 mg/kg) significantly improved only acquisition of AA, while verapamil (2.5 and 5.0 mg/kg) significantly improved both type of AA behavior in NBM-lesioned rats. These results suggest that altered calcium homeostasis might play significant role in pathogenesis of experimental induced Alzheimer's disease (AD) and that administration of calcium antagonist such as verapamil might successfully ameliorate disturbances of learning and memory appeared after lesions of NBM

Learning and memory in nucleus basalis magnocellularis-lesioned rats after transplantation of fetal frontal cortex

The effect of fetal frontal cortex transplantation on behaviour performance was examined in adult male Wistar rats with lesions of the nucleus basalis magnocellularis (NBM). Compared to intact and sham-operated controls, the rats tested ten or twenty days after bilateral electrolytic lesions of NBM exhibited the significant learning and memory impairments (acquisition and performance of two-way active avoidance) whereas spontaneous motor activity was not significantly altered. The animals which received allotransplants of fetal frontal cortex (from 18-day gestational rat fetuses) into NBM, two (''early'' transplantation -NBM-ET) or ten (''delayed'' transplantation-NBM-DT) days after lesioning, respectively, manifested the complete amelioration of noticed impairments when tested ten days after transplantation procedure. Corresponding sham-transplants groups (NBM-SET and NBM-SDT) showed only slightly improvement of acquisition but not performance of two-way active avoidance. The ability of the transplants to restore learning and memory in the NBM lesioned rats suggests that graft of fetal frontal cortex can functionally influence neuronal activity of the lesioned host brain