Now me talking about this thought does help me.

So here's another question about the hippocampus.

In this link in the 2nd paragraph it states "He later reported that newborn neurons migrated from their birthplace in the hippocampus to other parts of the brain."

http://www.ninds.nih.gov/disorders/b...nds_neuron.htm

Do only the newborn ones migrate, or do the ones that already exist in the hippocampus migrate as well? For this question, I do not need complex information--just a simple answer A.) the newborn ones or B.) both the newborn and the already-existing ones.