Basic Neurophysiology

Neurophysiology is the study of the function of the nervous system.

Membrane Ion Channels

All animal cells are enclosed in a plasma membrane, which separates its cytoplasm with the extracellular environment. Cell membrane has the structure of a lipid bilayer, with large molecules embedded in it. Concentration of ions are different across the cell membrane, with more sodium ions (Na+) and chloride ions (Cl-) outside the cell, and more potassium ions (K+) and negative charged protein molecules (A-) inside the cell. Selective ion channels at rest allow potassium ions (K+) cross the membrane easily, creating a voltage more negative inside the cell than outside, which is called resting membrane potential. The resting membrane potential of a neuron is about -70 mV.