Regenerative medicine in Alzheimer's disease.

Identifying novel, effective therapeutics for Alzheimer's disease (AD) is one of the major unmet medical needs for the coming decade. Because the current paradigm for developing and testing disease-modifying AD therapies is protracted and likely to be even longer, with the shift toward earlier intervention in preclinical AD, it is an open issue whether we can develop, test, and widely deploy a novel therapy in time to help the current at-risk generation if we continue to follow the standard paradigms of discovery and drug development. There is an imperative need to find safe and effective preventive measures that can be distributed rapidly to stem the coming wave of AD that will potentially engulf the next generation. We can define regenerative medicine broadly as approaches that use stem cell-based therapies or approaches that seek to modulate inherent neurogenesis. Neurogenesis, although most active during prenatal development, has been shown to continue in several small parts of the brain, including the hippocampus and the subventricular zone, suggesting its potential to reverse cognitive deficits. If AD pathology affects neurogenesis, then it follows that conditions that stimulate endogenous neurogenesis (eg, environmental stimuli, physical activity, trophic factors, cytokines, and drugs) may help to promote the regenerative and recovery process. Herein, we review the complex logistics of potentially implementing neurogenesis-based therapeutic strategies for the treatment of AD.