PSYC 2560 Chapter Notes - Chapter 4: Extracellular Fluid, Resting Potential, Membrane Potential
18 Dec 2013
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Level of dopamine is low in parkinson"s disease; helps control movement, thus shaking hands. However, dopamine is not an effective treatment because it does not penetrate the blood- brain barrier, but a drug l-dopa works. Membrane potential the difference in electrical charge between the inside and the outside of a cell: key to understanding how neurons work and how they malfunction. To record a neuron"s membrane potential, position the tip of one electrode inside the neuron and the tip of another electrode outside the neuron in extracellular fluid. The intracellular electrodes are called microelectrodes: tips are less than one-thousandth of a millimeter in diameter. When both tips are in extracellular fluid, the voltage difference between them is zero (0) But when the tip is inserted into a neuron a steady potential of about -70 millivolts (mv: means the potential inside the resting neuron is about 70mv less than outside the neuron. Resting potential -70mv (means it is polarized)
