New study raises questions about the birth of new neurons in human adult brain.A new research published in Nature this month has cast a shadow over a 20-year-old research that showed evidence of neurogenesis (the birth of new neurons) in the adult human hippocampus. The hippocampus is the part of the human brain that is responsible for processing memory. A second paper published in 2003 by Jonas Frisén and colleagues supported the 1998- paper and these findings have since then been used as leverage in the treatment of adult neuro-degenerative diseases, mood disorders and memory loss.The new research carried out by Arturo Alvarez-Buylla, a neuroscientist at the University of California, San Francisco, and researchers from China, Spain and Los Angeles, claims that adult human brain does not produce new neurons. The study was conducted in 59 human brains from fetal stages to 77 years of age. Even though there is evidence of newly formed neurons in fetuses up to one year after birth, Alvarez-Buylla & collaborators say that neurogenesis drops drastically in the teens to virtually ceasing in adult human brains.However, these new findings should not be taken so starkly, says Steven Goldman, a neurologist at the University of Rochester Medical Center and the University of Copenhagen. The study carried out by Alvarez-Buylla & collaborators can in fact increase the interest in and, consequently, funding towards more scientific research on the development and aging of human brain.