Читать книгу Neurobiology For Dummies - Frank Amthor - Страница 104

The sodium-potassium pump (refer to the section “Pumping Ions for Information,” earlier in this chapter) creates large concentration imbalances between the neuron’s cytoplasm and the extracellular fluid, and a net negative charge inside the neuron of about –65 mV (that is, the resting potential). How the neuron uses these concentration and charge imbalances for information processing is fundamental to what they do. Gated ion channels (refer to the “Ion selective channels” section, earlier in this chapter) change the neuron’s permeability to particular ions. These permeability changes lead to ionic current flow and corresponding changes in the membrane potential. Membrane potential changes control voltage-gated channels and neurotransmitter release.

In the following sections, we discuss what happens when the ionic permeability changes, specifically in the action potential.