1. The Revolution in Brain Science Neuroplasticity and Neurogenesis

2. The Brain The adult brain has long been considered stable and unchanging, except for the inevitable decline that occurs with aging. This view is being challenged with clear evidence that structural changes occur in the brain throughout life, including the generation of new neurons and other brain cells, and connections between and among neurons.

3. Structural Changes The structural changes seen in the brain may be required to provide the extra capacity we need for dealing with complexity.

4. Structural Changes (Con’t) It may also provide the underpinning for the adaptability and flexibility, or plasticity that is required for dealing with the variety of challenges that we face throughout life.

5. Repair Structural plasticity provides the mechanism for the brain to repair itself. All organs of the body have some capacity to repair themselves following minor injury. Skin, liver, heart, kidney, lung, and blood have some level of repair capacity, and most have the capacity to generate new cells to replace damaged ones, at least to a small extent.

6. Early Dogma Until recently, the brain was considered unique in its lack of ability to repair itself once it had matured to adulthood. “In the adult center the nerve paths are something fixed and immutable, nothing may be regenerated” (S. Ramon y Cajal, 1928). In general in was summed up as “try not to damage your brain, because there is no way to fix it.”

7. Neuroplasticity Neuro refers to the brain Plasticity refers to the ability to change itself, to change its structure and function.

8. Neuroplasticity occurs in the brain 1 – At the beginning of life: when the immature brain organizes itself. 2 – In case of brain injury: to compensate for lost functions or maximize remaining functions. 3 – Through adulthood: whenever something new is learned and memorized

10. Neurogenesis Neurogenesis means the production of new neurons. The observation that neurogenesis continues in the adult brain has led to the discovery that there are stem cells in the adult brain that generate the new neurons.

11. Stem Cells A stem cell is an uncommitted cell that, when it divides, can give rise to any or all the three main cell lineages of the brain: neurons, astrocytes, and oligodendrocytes.

12. Where does cell genesis occur? Neurogenesis, the process of generating new neurons, does not occur in every part of the brain. In fact, it only occurs in two areas: the hippocampus (discovered in 1998) and the olfactory bulb. New neurons in the hippocampus seem to help enhance learning and rebuild lost memories.

14. Summary The organization and layout of the nerve cells in the human brain is truly remarkable. The brain continues to change and adapt, as well as repair itself, throughout life. The brain follows an overall plan of development but then alters based on experience, stimulation, and the environment.

15. Brain Plasticity Read and make summary notes from the following website: http://faculty.washington.edu/chudler/plast.html 1. What are the benefits of brain plasticity? When is it not a benefit? 2. How could neurogenesis revolutionize the treatment of an unhealthy brain?