PS263 Chapter Notes - Chapter 7: Adenine, Mptp, Guanine
Document Summary
Brain disorders that impair movement also impair mood, memory, and cognition. Rigidity, muscle tremors, slow movements, difficulty initiating physical and mental activity. Early symptoms are loss of olfaction and psychological depression. Immediate cause is gradual loss of neurons in substantia nigra and thus a loss of dopamine-releasing axons to the striatum in the basal ganglia. With this loss of input, striatum decreases its inhibition of the globus pallidus which increases its inhibitory input to the thalamus. Genes make little or no contribution to late-onset parkinson"s disease but somewhat contribute to early onset. Chemical mptp causes parkinson"s, body converts it to mpp+ which accumulates in/destroys neurons that release dopamine, partly by impairing transort of mitochondria from the cell body to the synapse. Post synaptic neurons react to the loss of input by increasing dopamine receptors. People exposed to hazardous environmental chemicals that damage cells of substantia nigra (insecticides, herbicides, fungicides)
