Neurogenesis in the adult hippocampus.

The surprising finding that the adult hippocampus produces new neurons throughout life has challenged many old views about the brain, because the brain appears to be plastic enough to integrate new neurons. Research on adult hippocampal neurogenesis also allows one to study neuronal stem or progenitor cells in the mature and working brain. It therefore will provide key information necessary for any attempt to use neuronal stem cells in situ to treat neurological disease. Although this new strategy holds great promise, a large number of questions, some of which are discussed herein, remain to be addressed.