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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. Lecture XII: Plasticity. Neuromorphological. Early Molding
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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
Lecture XII: Plasticity Neuromorphological Early Molding Tweeking Functional Adult On the Cellular Level (Hebb Rule)
Neuromorphological Plasticity Organization guided by input Whisker and Neuronal Connections (9) Periphery input to cortex No Genetic Predisposition Experiment: Label Eye-Specific Neurons (12) Human: Visual Cortex (11)
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 XII. Experience & Critical Periods (aka Plastics)
Neuromorphological Plasticity Organization guided by input Whisker and Neuronal Connections (9) Periphery input to cortex No Genetic Predisposition Don’t use it, lose it. (14,15) Experiment: Label Eye-Specific Neurons (12) Human: Visual Cortex (11) Wide Branching to Delineated (13)
Functional Plasticity Ends with Puberty Reinforcing Good Connections Early vs Late Bilinguals (21,22,23,24)
“Early” bilingual subject - Broca’s Area (Brodmann’s 44+) “Late” bilingual subject - Broca’s Area (Brodmann’s 44+) Language Production XII. Experience & Critical Periods (aka Plastics)
Functional Plasticity Ends with Puberty Reinforcing Good Connections Early vs Late Bilinguals (21,22,23,24) Lose unused neurons (25)
Adult Plasticity Reinforcement through experience; adjustments Quickly learned and lost (half-life) Demo
Hebb Rule Persistent firing of a cell by a different neuron results in metabolic or growth process change (37). Increase post-synaptic sensitivity (38) Create new synapses (39)
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 Substantianigra results in lost dopaminergic neurons • Loss of thalamic output from basal ganglia • Reduced excitation of motor neurons in the superior collicus and cortex
THE BRAIN ATLAS, 3rd ed p 74 SubstantiaNigra Lecture XIII. Brain Diseases - I.
THE BRAIN ATLAS, 3rd ed p 139 Substantia Nigra Lecture XIII. Brain Diseases - I.
Thalamus GlobusPallidus Caudate Nucleus & Putamen Decreased Excitation of Cortex SubstantiaNigra Subthalamic Nucleus
Thalamus Caudate Nucleus & Putamen GlobusPallidus Subthalamic Nucleus SubstantiaNigra