PSY290H1 Chapter Notes - Chapter 4: Excitatory Postsynaptic Potential, Inhibitory Postsynaptic Potential, Axon Hillock
Document Summary
Membrane potential is the difference in charge between the inside and the outside of a cell. This is recorded with one electrode inside and one electrode outside the cell. The electrodes put inside the cell are microelectrodes, they are very small. The resting potential is -70 mv, meaning inside of the cell is 70 mv less than the outside. There are many diff kinds of ions in neurons but the most important ones are sodium ions (na+) and potassium ions (k+). In resting neurons, there are more na+ ions outside the cell and more k+ ions inside the cell. Despite this pressure, na+ can"t come rushing into neurons because sodium ion channels are closed when the neuron is resting. The potassium ion channels are open in resting neurons, but they don"t exit the neuron bc of the negative resting potential that keeps them inside.
