Figure 1.

Age effects on adult hippocampal neurogenesis. Even in the inaugural paper of the field, the original description by Altman and Das (1965) of adult hippocampal neurogenesis contained data revealing how strongly postnatal and adult neurogenesis decrease with age. Today, absolute numbers can be assigned to the different time points, revealing that, throughout most parts of the adult life, hippocampal neurogenesis ranges on a minute scale. (From Altman and Das 1965; reprinted, with kind permission, by Joseph Altman and John Wiley and Sons © 1965.)