PSY290H1 Chapter Notes - Chapter 4: Striatum, Outlast, Myelin
Document Summary
Nerve cells in the substantia nigra are dying. These produce dopamine which is delivered to the striatum which helps control movement. Without dopamine, the striatum can"t do its job. Dopamine isn"t an effective treatment because it doesn"t readily penetrate the blood-brain barrier. However, l-dopa can do so and is turned to dopamine in the brain. Membrane potential = the difference in electrical charge between the inside and outside of a cell, which is -70mv. Na ions tend to be driven into neurons by the high concentration outside the membranes. The sodium-potassium pumps maintain a high na concentration outside the membrane. K ions tend to move out of the neuron because of high internal concentration. There is little resistance in the neural membrane to the passage of cl ions, so they are readily forced out due to negative internal potential. Once they accumulate outside the membrane, they tend to move down their concentration gradient back into the neuron.
