1. 1 Psychology 304: Brain and Behaviour Lecture 23

2. 2 Development of the Nervous System and Neurodevelopmental Disorders 2. What neurodevelopmental disorders have been identified? 1. Is the adult brain capable of change?

3. 3 1. review evidence of neuroplasticity in adulthood. By the end of today’s class, you should be able to: 2. describe the causes and symptoms of disorders associated with neurodevelopmental abnormalities.

4. 4 Is the adult brain capable of change? Neuroplasticity was thought to be restricted to early development. However, recent research has demonstrated that mature brains are capable of substantial reorganization. Among the research findings that have demonstrated the neuroplasticity of the mature brain are two lines of evidence:

5. 5 1. Neurogenesis in the adult brain  A number of studies have demonstrated that new neurons are constantly created in the olfactory bulb and hippocampus.  Exposure to enriched environments and regular exercise contribute to neurogenesis in the adult brain.

6. 6 Neurogenesis in the Adult Brain

7. 7 2. Reoganization of the adult cortex  Sensory and motor experiences in adulthood can lead to reorganization of sensory and motor cortical maps in the brain. The neuroplasticity of the mature brain suggests promising treatments for degenerative brain diseases.

8. What neurodevelopmental disorders have been identified? The causes of neurodevelopmental disorders are typically genetic, although some arise from prenatal dietary deficiencies and neurotoxin exposure. 1. Anencephaly  Occurs when the anterior neural tube does not close, resulting in incomplete brain development. Caused by genetic abnormalities, folic acid deficiencies, and/or exposure to neurotoxins.

9. 9 Anencephaly: Incomplete Brain Development

10. 10 Anencephaly: Incomplete Brain Development

11. 2. Spina bifida  Occurs when the posterior neural tube does not close, resulting in spinal cord defects and, in many cases, paralysis of the lower limbs. Caused by genetic abnormalities, folic acid deficiencies, and/or exposure to neurotoxins.  Four forms identified: occulta, meningocele, meningomyelocele (cystica) and myeloschisis.

12. 12 Spina Bifida: Four Forms

13. 13 Development of the Nervous System and Neurodevelopmental Disorders 2. What neurodevelopmental disorders have been identified? 1. Is the adult brain capable of change?