Neurogenesis in the adult brain exists and is functionally significant
Original Q&A :: About these Q&A :: Other Q&AQ: As I understand it new neurons can form when prompted. What would prompt one to form? I was wondering if those new neurons initiated new capabilities or put another way can the brain improve on itself?
A: Don,
There are special regions in the brain where the neurons indeed can be newly formed and first this capability was discovered in the hippocampus. In adult rodents, new neurons continue to be produced in the hippocampus throughout entire life (1, 2).
In animal models, formation of new neurons, neurogenesis, is increased by cognitive tasks. This process can be experimentally stopped and when it does, learning and memory suffer. In humans, studying neuron samples taken from specific brain region, hippocampus or dentate gyrus, and cultivated in vitro showed that the stronger regenerative properties of neurons in vitro, the higher this particular patient's ability to learn and form new memories (3).
Researchers at La Jolla, California, reported that the survival of newly formed neurons is increased when animals were placed into a more complex environment, proving that neurogenesis in adults may be stimulated by new experiences that might consist navigation in a water maze as well as swimming, wheel running and housing (4).
What are newly neurons are capable of? researchers explored the mechanisms of growing new synapses on neurons born in the adult mouse hippocampus rendering functional significance of these new neurons (5)
Recently, more brain structures able to produce new neurons were reported, such as the subventricular zone, from where new neurons migrate along the so called rostral migratory system with astrocytes being involved in the process (6).
Sources
1. Kaplan, M. S. & Hinds, J. W. Science 197, 1092−1094 (1977).
3. Bayer, S. A. Exp. Brain Res. 46, 315−323 (1982).
3. J. Altman. Science 30 March 1962: 135, no. 3509, 1127 - 1128
4. Kempermann G, Kuhn H, Gage F. Nature. 1997 Apr 3;386(6624):493-5
5. N. Toni et al., Nature Neuroscience 10, 727 - 734 (2007)
6. L. Welberg, Nature Reviews Neuroscience 2010, 11, 610-611
