2. Since Last Discussion: XII: Experience and Critical Periods (aka, Plastics) XIII: Brain Diseases I XIV: Brain Diseases II XV: Genetics and Human Brains: Clues from Abnormalities XVI: Reflections on Higher Brain Functions

3. Lecture XII: Plasticity Neuromorphological On the Cellular Level (Hebb Rule) Functional Adult Early Molding Tweeking

4. Neuromorphological Plasticity Organization guided by input Whisker and Neuronal Connections (9) Periphery input to cortex No Genetic Predisposition Human: Visual Cortex (11) Experiment: Label Eye- Specific Neurons (12)

5. October 11, 2010 XII. Experience & Critical Periods (aka Plastics) 5 Labeled axons from visual thalamus to visual cortex in monkeys of different ages Axons related to left eye are red and those related to right eye are blue

6. Neuromorphological Plasticity Organization guided by input Whisker and Neuronal Connections (9) Periphery input to cortex No Genetic Predisposition Human: Visual Cortex (11) Don’t use it, lose it. (14,15) Experiment: Label Eye- Specific Neurons (12) Wide Branching to Delineated (13)

7. Functional Plasticity Reinforcing Good Connections Ends with Puberty Early vs Late Bilinguals (21,22,23,24)

8. October 11, 2010 XII. Experience & Critical Periods (aka Plastics) 8 “Early” bilingual subject - Broca’s Area (Brodmann’s 44+) “Late” bilingual subject - Broca’s Area (Brodmann’s 44+) Language Production

9. Functional Plasticity Reinforcing Good Connections Early vs Late Bilinguals (21,22,23,24) Ends with Puberty Lose unused neurons (25)

10. Adult Plasticity Reinforcement through experience; adjustments Demo Quickly learned and lost (half-life)

11. Hebb Rule 1.Increase post-synaptic sensitivity (38) 2.Create new synapses (39) Persistent firing of a cell by a different neuron results in metabolic or growth process change (37).

12. October 11, 2010 XII. Experience & Critical Periods (aka Plastics) 12

13. October 11, 2010 XII. Experience & Critical Periods (aka Plastics) 13

14. Lecture XII: Brain Disease: Parkinson’s Phenotype: Characterized by an inability to initiate movement (walking) or terminate movement, tremors at rest, rigidity and minimal facial expressions. Pathophysiology: Loss of Substantia nigra results in lost dopaminergic neurons Loss of thalamic output from basal ganglia Reduced excitation of motor neurons in the superior collicus and cortex

15. October 13, 2010Lecture XIII. Brain Diseases - I.15 Substantia Nigra THE BRAIN ATLAS, 3 rd ed p 74

16. October 13, 2010Lecture XIII. Brain Diseases - I.16 THE BRAIN ATLAS, 3rd ed p 139 Substantia Nigra

17. Globus Pallidus Caudate Nucleus & Putamen Subthalamic Nucleus Substantia Nigra Thalamus Decreased Excitation of Cortex

18. Globus Pallidus Caudate Nucleus & Putamen Subthalamic Nucleus Substantia Nigra Thalamus

19. Increased Excitation