Summary: Nerve cells encode and transmit information in the form of
electrical signals. The production of these impulses depends
upon the cooperative effort of a number of distinct ion
channels. These channels conduct the ionic currents
responsible for the cell's electrical properties: its resting
potential, its sensitivity to stimulation and the shape and
duration of its action potential. In short, they shape the cell's
input­output properties. Any given neuron will typically have
one or more different inward currents and perhaps four or more
outward currents. Together, these currents, each conducted by
a different channel, give rise to the overall electrical properties
of the cell. Not only do these channels shape their electrical
environment, they also sense it and alter their activity in
response to it. From this complex interplay between electrical
environment and channel activity arises the cell's electrical
character.
Eukaryotic genomes encode a staggeringly large number of
distinct ion channels (Jan and Jan, 1990; Wei et al., 1996). The
choice of which channels to express is an extremely significant
cellular decision because it delimits the range of electrical

Source: Atkinson, Nigel - Section of Neurobiology, Division of Biological Sciences, University of Texas at Austin

Collections: Biology and Medicine