Development and Plasticity of the Brain

1. Development and Plasticity of the Brain

2. Development of the Brain • Plasticity of the brain refers to the idea that the brain is constantly changing throughout the lifetime. • YouTube - The Phenomenon of Neuroplasticity

3. Development of the Brain • Development of the brain is due to both experience and physical maturation. • Rapid development especially occurs early in life. • Prefrontal cortex develops rapidly between 7 and 12 months (allowing for object permanence).

4. Development of the Brain. • The human central nervous system begins to form when the embryo is approximately 2 weeks old. • The dorsal surface thickens forming a neural tube surrounding a fluid filled cavity. • The forward end enlarges and differentiates into the hindbrain, midbrain and forebrain. • The rest of the neural tube becomes the spinal cord.

5. Fig. 5-3, p. 123

6. Development of the Brain • The development of neurons in the brain involves the following four processes: • Proliferation • Migration • Myelination • synaptogenesis

7. Development of the Brain • Proliferation refers to the production of new cells/ neurons in the brain primarily occurring early in life. • Early in development, the cells lining the ventricles divide. • Some cells become stem cells that continue to divide • Others remain where they are or become neurons or glia that migrate to other locations.

8. Development of the Brain • Migration refers to the movement of the newly formed neurons and glia to their eventual locations. • Migration occurs in a variety of directions throughout the brain. • Migration occurs via cells following chemical paths in the brain of immunoglobins and chemokines.

9. Development of the Brain • Myelination refers to process by which glia produce the fatty sheath that covers the axons of some neurons. • Myelin speeds up the transmission of neural impulses. • Myelination first occurs in the spinal cord and then in the hindbrain, midbrain and forebrain. • Myelination occurs gradually for decades.

10. Development of the Brain • Synaptogenesis is the final stage of neural development and refers to the formation of the synapses between neurons. • Occurs throughout the life as neurons are constantly forming new connections and discarding old ones. • Synaptogenesis slows significantly later in the lifetime.

11. YouTube - Brain Plasticity • Read pages 356- 358 of your text • Complete pages 102- 105 of your workbook. • Review 14.4