And that's what happened. BrdU was found inside brain cells of all five patients. By using specific markers for nerve cells, Gage and colleagues showed that BrdU was present in nerve cells. This proved that the adult human brain is capable of creating new nerve cells. Thestudy, however, doesn't tell us if the newly formed nerve cells are functional or active.
Nerve cells are large, complicated, highly specialized cells.
It seemed unlikely that such cells would be capable of duplicating and multiplying. Perhaps by a process similar to that used before birth. In the developing embryo, nerve cells are formed from stem or progenitor cells. Scientists speculate that new nerve cells are created from these stem cells. To date, studies in adult rodents and monkeys including Gage's study in humans have found new nerve cell creation in one brain region, the hippocampus-a region involved in memory.