Deep Brain Stimulation . A thin insulated wire called a lead. or electrode that is placed into the brain 2. The neurostimulator similar to a heart pacemaker, which is usually placed under the skin near the collarbone but may be placed elsewhere in the body 3. Another thin insulated wire called an extension that connects the lead to the neurostimulatorDeep Brain Stimulation 1. A thin, insulated wire called a lead, or electrode that is placed into the brain 2. The neurostimulator, similar to a heart pacemaker, which is usually placed under the skin near the collarbone, but may be placed elsewhere in the body 3. Another thin, insulated wire called an extension that connects the lead to the neurostimulator