Methods and apparatus for selectively applying electrical energy to a target location within a patient's body, particularly including tissue in the spine. In a method of the invention high frequency (RF) electrical energy is applied to one or more active electrodes on an electrosurgical probe in the presence of an electrically conductive fluid to remove, contract or otherwise modify the structure of tissue targeted for treatment. In one aspect, a dura mater and spinal cord are insulated from the electrical energy by an insulator positioned on a non-active side of the probe. In another aspect, a plasma is aggressively formed in the electrically conductive fluid by delivering a conductive fluid to a distal end portion of the probe and aspirating the fluid from a location proximal of the return electrode. In another aspect, a distal end of an electrosurgical probe having at least one electrode on a biased, curved, bent, or steerable shaft is guided or steered to a target site within an intervertebral disc having a disc defect for treatment of tissue to be treated at the target site by the selective application of electrical energy thereto.