July 26, 2012 Excitation of neurons depends on the selected
influx of certain ions, namely sodium, calcium and potassium
through specific channels. Obviously, these channels were
crucial for the evolution of nervous systems in animals. How
such channels could have evolved their selectivity has been a
puzzle until now. Yehu Moran and Ulrich Technau from the
University of Vienna together with Scientists from Tel Aviv
University and the Woods Hole Oceanographic Institution (USA)
have now revealed that voltage-gated sodium channels, which are
responsible for neuronal signaling in the nerves of animals,
evolved twice in higher and lower animals. These results were
published in Cell Reports. The opening and closing of ion
channels enable flow of ions that constitute the electrical
signaling in all nervous systems. Every thought we have or every
move we make is the result of the highly accurate opening and
closing of numerous ion channels. Whereas the channels of most
lower animals and their unicellular relatives ca