[The dentate gyrus neurogenesis: a common therapeutic target for Alzheimer disease and senile depression?].

Neurogenesis persistently occurs even in the adult dentate gyrus. Since most of the anti-depression therapies increase adult neurogenesis, suppressed neurogenesis has been proposed to be one of the candidate etiologies of depression. Here we show that Cerebrolysin, an anti-dementia drug that improves the activity of daily living of Alzheimer disease (AD) patients, can enhance neurogenesis and spatial learning of adult female rats. Regarding the anatomical importance of the dentate gyrus in AD pathogenesis and the frequent association of depressive symptoms in preclinical phase of AD, our finding suggests a possibility that AD involves suppressed neurogenesis causing the decreased activity of daily living. Pseudodementia might also involve suppressed neurogenesis but differ form AD since the neurodegenerative process in AD may be irreversible.