PROJECT SUMMARY The number of people living with dementia doubles every five years, creating an ever-growing health, social, and economic catastrophe for the future. There are currently no effective treatments for dementia. Dementia due to Alzheimers disease, Lewy Body dementia, and Parkinsons Disease dementia is associated with degeneration of the nucleus basalis if Meynert (NBM). This results in the loss of the cholinergic supply to the cortex, cortical atrophy, and the loss of a variety of abilities associated with that cortex. The potential to provide symptomatic relief through the electrical stimulation of the NBM has been recognized, with early clinical trials underway. On the other hand, the potential for NBM deep brain stimulation (DBS) to modify the course of the disease through stimulation induced neurogenesis has not been evaluated, despite multiple lines of evidence demonstrating stimulation induced neurogenesis in other stuctures. We have demonstrated this potential in our preliminary data. The goal of this proposal is charcterize and optimize this potential. To this end we will evaluate the neuroregenerative effects and cognitive improvements associated with continuous NBM stimulation in demented and control rats and monitor for adverse effects on sleep-wake cycles and stress. Because of the role that the NBM plays in sleep and the potential stress of always being alert and vigilant, we will evaluate ‘activity-dependent stimulation’ as an alternative strategy to optimize the positive effects of NBM stimulation on neurogenesis, learning, and health of the animal. The optimal parameters for disease modification will be important for the design of future clinical trials of NBM stimulation.