Alzheimer's disease and neural transplantation as prospective cell therapy.

It has long been recognised that Alzheimer's disease (AD) patients present an irreversible decline of cognitive functions as consequence of cell deterioration in the forebrain cholinergic projection system (FCPS), particularly, in a structure called nucleus basalis of Meynert (nbM). The reduction of the number of cholinergic cells in the FCPS disrupts not just its functions and direct connexions but also the modulation of other systems causing interference in several aspects of behavioural performance including arousal, attention, learning and emotion. It is also common knowledge that AD is an untreatable degenerative disease with very few temporary and palliative drug therapies. Neural stem cell (NSC) grafts present a potential and innovative strategy for the treatment of many disorders of the central nervous system including AD, with the possibility of providing a more permanent remedy than present drug treatments. After grafting, these cells have the capacity to migrate to lesioned regions of the brain and differentiate into the necessary type of cells that are lacking in the diseased brain, supplying it with the cell population needed to promote recovery. The present article aims to review the main aspects of Alzheimer's disease and to explore the use of neural stem cells grafts as alternative treatment for the consequent functional deterioration.