1. Brain and Behavior: Neurobiology of Everyday Life HOW DO I GET TO BE ME? Miracle of Brain Development Week #3 Daniel G. Amen, MD

2. First, some brain basics

3. THE BRAIN IS INVOLVED IN EVERYTHING YOU DO How you... How you...  think  feel  act  interact Who you are as a... Who you are as a...  therapist  child  parent  spouse Brain Basics #1

4. When your brain works right, you work right When your brain works right, you work right When your brain doesn’t work right, you can’t work right Brain Basics #2

5. BRAIN IS MOST COMPLEX ORGAN 100 billion neurons, trillion glial cells 100 billion neurons, trillion glial cells each neuron connected to many other cells each neuron connected to many other cells 1,000,000,000,000,000 connections in brain 1,000,000,000,000,000 connections in brain more connections than stars in universe more connections than stars in universe 2% of body’s weight 2% of body’s weight Uses 20-30% of the calories consumed Uses 20-30% of the calories consumed Brain Basics #3

6. BRAIN IS VERY SOFT Brain is very soft Brain is very soft u consistency of soft butter butter Skull is really hard Skull is really hard u many ridges Brain Basics #4

7. TYPICAL NEURON Brain Basics #5

8. NERVE CELL PARTS Brain Basics #6 n Dendrites = nerve antenna, receivers n Cell body = contains nucleus, protein making machinery, mitochondria (energy makers) n Axons = sends signals, action potentials to other cells, wrapped with myelin to protect and speed signals along

9. GRAY VS WHITE MATTER Brain Basics #7 Gray matter = cells bodies Gray matter = cells bodies White matter = mylenated nerve cell tracks, connects hemispheres White matter = mylenated nerve cell tracks, connects hemispheres Interneurons = local connections Interneurons = local connections Projection neurons = sends signals to other parts of brain and body Projection neurons = sends signals to other parts of brain and body

10. GRAY VS WHITE MATTER Brain Basics #7

11. WHITE TRACTS Brain Basics #7

12. TYPICAL SYNAPSE Brain Basics #8

13. NEUROTRANSMITTERS How the Brain Communicates with Itself Acetylcholine (ACh) – mostly excitatory  muscle problems, Alzheimer’s, learning problems Serotonin (5-HT) – excitatory  depression, OCD, eating disorders, sleep, pain  depression, OCD, eating disorders, sleep, pain Brain Basics #9a

14. NEUROTRANSMITTERS Dopamine (DA) – excitatory and inhibitory  Parkinson’s, ADD, addictions, depression, schizophrenia Norepinephrine (NE) – excitatory  depression, ADD, anxiety Epinephrine (E) – excitatory  anxiety  anxiety Brain Basics #9b

15. NEUROTRANSMITTERS Gamma-aminobutyric acid (GABA) – inhibitory  seizures, bipolar disorder, anxiety, pain  seizures, bipolar disorder, anxiety, pain Glutamate – excitatory  most widely available neurotransmitter, paradoxically both main neurotransmitter for memory and main one responsible for cell death Brain Basics #9c

16. NEUROGENESIS Brain Basics #10 1990s overturned 100 year old doctrine 1990s overturned 100 year old doctrine Through life BRAIN MAKES NEW NEURONS Through life BRAIN MAKES NEW NEURONS Programmed cell death is important, BALANCE Programmed cell death is important, BALANCE Long term potentiation Long term potentiation Learning and physical exercise encourages neurogenesis Learning and physical exercise encourages neurogenesis

17. DEVELOPMENT Brain Basics #11 Low activity at birth Low activity at birth Ramps up from 0-3, stays high til 5 Ramps up from 0-3, stays high til 5 Pruning starts at 5, levels off at 10 (tracks that are not used) Pruning starts at 5, levels off at 10 (tracks that are not used) Brain continues to be active til 40 Brain continues to be active til 40 Repair mechanisms less efficient after 40 Repair mechanisms less efficient after 40 After 40, need to encourage health After 40, need to encourage health

18. n Brain constructed in levels w/different fxns n Development influenced by genes, environment and experience n Increased brain complexity increases behavioral complexity n Develops different rates (PFC and teens) n Children do not have social skill as adults The Brain Miracle

19. Social Development

20. Stages of Brain Development 1. Cells birth (neurogenesis, glialgenesis) 2. Cell migration 3. Cell differentiation 4. Cell maturation (dendrite/axon growth) 5. Synaptogenesis (formation of synapses) 6. Cell death and synaptic pruning 7. Myelogenesis (formation of myelin)

21. Cell Birth n Cells lining neural tube, brain’s nursery, stem cells (capacity for self renewal) n Cortex begins development at 7 wks, mostly complete by 20 weeks n 5 mos preme can live outside n 5-9 months a very vulnerable time (anoxia, toxins – neurogenesis mostly complete)

22. Cell Migration n Cells migrate along radial glial cells n Cortex has 6 layers -- lower layers laid u layers 5-6: output to other brain areas u layer 4: input – sensory u layers 1-3: intergrative functions

23. Cell Maturation n Dendrite arborization (branching) n Continues after birth, grow slowly n Axon growth, up to 1mm a day (fast growth) n Growth factors involved n Experience involved – Hebb’s kitchen rats

24. Synaptogenesis n 10 14 synapses n Too many for genes alone to determine n General guidelines for layout, guided by clues, signals, hormones and experience n Simple connections by 5 mos prenatally n Complex connections by 7 mos n Increase rapidly after birth n Visual cortex doubles from 2-4 mos of an infant

25. Cell Death & Synaptic Pruning n Overproduction of neurons and synapses and subsequent loss n 42% of synapses die n Prunes unnecessary/incorrect synapses n May lose up to 100,000 per second n “Use it or lose it” n Experience, opportunity, stress has great influence n Programmed cell death -- apoptosis

26. Myelinization n Myelin wraps/insulates neurons n Increases efficiency of function n Begins after birth n Continues into adulthood n Maturity is associated with areas that develop last, esp the PFC develop last, esp the PFC n Drug abuse/stress can delay development

27. Influences On The Brain BiologyPsychology Social

28. Biological Influences Genetics Prenatal exposure Health Toxic exposure Trauma Brain system health Hormones and neurotransmitters

29. Psychology Influences Bonding Stimulation Self talk Experiences Parenting -- New Skills for Frazzled Parents

30. Social Influences Support systems Stresses Opportunities Modeling Effective living