to complex electrical properties of extracellular space. The fact that the extracellular space is not homogeneous, and composed of a complex aggregate of highly conductive fluids and low-conductive and capacitive membranes, can exert strong low-pass filtering properties. Ionic diffusion, which plays an important role in membrane potential variations, can also act as a low-pass filter. References External links Mechanisms of local field potentials (Scholarpedia) Electrophysiology Action potentials