Psychology 2220A/B Chapter Notes - Chapter 4: Axon Hillock, Substantia Nigra, Saltatory Conduction

• School: Western University
• Department: Psychology
• Course: Psychology 2220A/B
• Professor: Scott Mac Dougall- Shackleton

Document Summary

A small group of nerves called the substantia nigra were dying - these neurons make dopamine which they deliver to the striatum. As the substantia nigra is dying, the amount of dopamine delivered to the striatum decreases. The striatum helps control movement, but it needs dopamine for that. Dopamine isn"t an effective treatment for pd b/c it doesn"t readily penetrate the blood-brain barrier. L-dopa - the chemical precursor of dopamine - penetrates the bbb and is converted into dopamine once inside the brain -> effective treatment. Membrane potential - the difference in electrical charge between the inside and the outside of a cell. Requires the tip of one electrode inside (intracellular requires microelectrodes) and one outside the neuron. Both tips in the extracellular fluid (outside the neuron), voltage diff = 0. When tip of intracellular electrode is inserted into a neuron, a steady potential of about -70mv is recorded.