ABSTRACT
A hundred years ago the neuron was established as an independently functioning unit through the anatomical studies of Ramon y Cajal and his mastering of staining techniques. Electrical capacitance was then measured, the squid giant axon was discovered to be an invaluable preparation to work on, and to show that membrane conductance increases during the nerve impulse. Classical cable theory provides a framework for understanding propagation of action potentials along an excitable fibers like axons. The theory originally came from the derivation of the cable equation for use in calculations essential to the first trans-Atlantic telegraph cable, around 1855, by Lord Kelvin. The existence of dendritic spine has been known since the turn of the century, but interest in these tiny projections has been renewed in the last twenty years by anatomical investigations and interesting questions on spine function and their potential plasticity.
