Abstract: An implantable electrode is provided for treating tissue in a patient with energy. In one variation of this embodiment, the implantable electrode includes a shaft having a length sufficient to extend from outside a body of the patient to adjacent a tissue site to be treated, an electrode core attached to a distal end of the shaft capable of delivering a form of energy to the tissue site, one or more wires which extend from a proximal end of the shaft to the electrode core such that an energy source external to the patient can be coupled to the wire for delivering energy to the electrode core, and a head formed at least in part of a soluble and porous material which at least partially surrounds the electrode core and becomes conductive when contacted with an energy conducting liquid. According to this variation, the shaft also includes a lumen for delivering energy conducting liquid from outside the body to the head.