NEUR 310 Lecture Notes - Lecture 12: Retina, X-Ray Crystallography, Resting Potential
Document Summary
Two families of proteins that are responsible for the electrical properties of neurons: pumps - responsible for the electrical/concentration gradients. This is where the energy comes from - the atp that is hydrolyzed when the pumps work against the gradient (pumping sodium out; potassium in) Ion channels - they enable the neurons to gate the flow ions back and forth across the membrane, on a very fast time scale: responsible for the rapid changes in electrical properties. Intracellular ligand-gated ion channels - e. g. ion channels in the photoreceptors in the retina are gated by cgmp: mechanically-gated ion channels - responsive to stretching of the membrane, e. g. responsible for the ability to sense touch. Potassium channels: voltage-gated potassium channels are responsible for the falling (repolarization) phase of the action potential. The action potential results from the inward flow of sodium ions - which deactivates after ~1 ms - and an outward flow of potassium ions.