NEUROSCI 201 Study Guide - Midterm Guide: Synaptobrevin, Syntaxin, Snap25
7 Apr 2016
School
Department
Course
Professor
Document Summary
Hodgekin + hukexly: said that ion channels must have: must allow large influxes of ions, be voltage dependent, selective to certain ions, pass ions through a gradient. Events leading to an action potential: resting membrane (leak k+ channels) - -40 to -70 mv graded potential causes sufficient depolarization, opens sodium channels: na+ rushes into the cell, causing depolarization. Then sodium channels are inactivated (absolute refractory) and potassium voltage gated channels are opened. Slower to close, hyperpolarization, finally close back to resting. Action potential to nt action potential reaches pre-synaptic button causes release of calcium gated ion channels ca into the cell. Hodgkin and huxley postulated 4 properies of ion channels o o o o. Because ionic currents are large, channels had to be capable of allowing ions to move across the membrane at high rates. Because ionic currents low based on electrochemical gradients, the channels had to uilize these gradients.
