PS263 Lecture Notes - Lecture 8: Huntingtin, Chromosome, Subthalamic Nucleus
Document Summary
Main route: direct pathway: axons from substantia nigra release dopamine that excites caudate nucleus and putamen which inhibit globus pallidus which inhibits parts of thalamus. Loss of dopamine activity in substantia nigra= less stimulation of motor cortex and slower onset of movements: environmental influences: Implicated exposure to toxin: some drugs have caused it (heroin) Substance: mptp, chemical that body converts to mpp+ which accumulates in and then destroys neurone that release dopamine. Ability to learn and improve new movements especially limited; disease is associated with gradual, extensive brain damage especially in caudate nucleus, putamen, globus pallidus but also in cerebral cortex. Also suffer psychological disorders including depression, sleep disorders, memory impairment, anxiety, hallucinations and delusions, pror judgement, alcoholism, drug abuse and sexual disorders. Chromosomal examination can predict whether person will get disease and when. Critical area of gene includes sequence of bases c-a-g which is repeated 11-24 times in most people which produces string of 11-24 glutamines in resulting protein.
