PSYC 271 Chapter Notes - Chapter 4: Axon Hillock, Axon Terminal, Lipid Bilayer Fusion

• School: Queen's University
• Department: Psychology
• Course: PSYC 271
• Professor: Richard Beninger

Document Summary

Calculating electrostatic pressure (cl = 70mv, k = 90mv, na. = 120mv) shows sodium is still being driven in against gradients: differential permeability of ions - k+ and cl- pass readily but na+ and negative protein ions do not pass at all. This is passive: sodium-potassium pump: an active energy-consuming transporter that exchanges 3 na+ out of cell for transporting 2 k+ ions into cell. 70mv to -60mv, for example) o a hyperpolarizing effect (decrease from -70mv to. 75mv): postsynaptic depolarizations are excitatory postsynaptic potentials (epsps), while hyperpolarizations are inhibitory postsynaptic potentials (ipsps). 4. 3 integration of psps, generation of action potentials: whether a neuron fires or not depends on balance between excitatory and inhibitory signals it receives. Action potentials are not generated at the axon hillock, but adjacent to the axon: to depolarize a neuron, the sum of psps at the axon hillock must reach the threshold of excitation (-65mv) to generate an action potential.