A method of treating an intervertebral disc is provided. The method comprises introducing a probe with an electrode into contact with the nucleus pulposus of the disc, and conveying radio frequency ablation energy from the electrode into the nucleus pulposus of the disc. For example, if the disc has a herniated region, the electrode can be placed into contact with the nucleus pulposus within the herniated region (e.g., by steering the electrode), and the ablation energy can be conveyed directly into the herniated region. The electrode can also be placed into contact near the center region of the disc, in which case, the ablation energy can be conveyed into the center region. In any event, tissue is removed, which may decompress the disc or provide some other therapeutic result. The method further comprises circulating a cooling medium through the probe in thermal contact with the electrode. By cooling the electrode, tissue is more efficiently ablated from the disc.