PSYC 280 Lecture Notes - Lecture 3: Resting Potential, Axon Hillock, Sodium Channel

• School: Simon Fraser University
• Department: Psychology
• Course: PSYC 280
• Professor: Evan Caldbick

Document Summary

At rest, every cell, including neurons negatively charged outside of cell relative to inside. Inside of cell about negative 16 millivolt compared to outside. Membrane itself differentially permeable to ions, making it somewhat leaky. One of principle mechanisms used to establish concentration gradient - sodium potassium pump - protein exchanging 3 sodium ions for 2 potassium ions b/w intra & extra cellular space. Cumulatively, there is balance of ions corresponding to concentration & charge gradients. At rest, membrane has significantly more positively charged sodium & calcium ions & negatively charged chlorine ions outside of cell & more positively charged potassium ions & negatively charged proteins inside of cell. Balance is what generates resting membrane potential. Once resting membrane potential established, electrochemicals stimulations that cause small deviations from it can be basis for info transmission. When stimulation increases negative potential inside cell, it is called hyperpolarizing response. When decreases negative potential, called depolarizing response.