Effects of Deep Brain Stimulation in Treatment Resistant Major Depression

The target point for DBS in major depression disorder is located lateral to the ventral tegmental area (VTA) in the midbrain at the branching point of the superolateral branch (slMFB) from the main medial forebrain bundle (MFB). The exact stimulation coordinates are: MNI152 coordinates: left: x(lat.)=-5, y(ap)=-14, z(vert.)=-8 right: x(lat.)=5, y(ap)=-14, z(vert.)=-9 MCP coordinates: eft: x(lat.)=-6, y(ap)=-1, z(vert.)=-6 right: x(lat.)=4, y(ap)=-1, z(vert.)=-7 All coordinates refer to the MNI152 brain. Legend: slMFB = superolateral branch of medial forebrain bundle, MNI152=Montreal Neurologic Institute brain 152 coordinates, MCP = mid-commissural point coordinates, lat. = lateral, ap= antero-posterior, vert. = vertical. More information can be found at: http://goo.gl/n9sWV In addition to the described intervention, we will record EEG activity within the implanted regions during cognitive paradigms (Fell and Axmacher, Nat Rev Neurosci 2011). Specifically, we will investigate the neural mechanisms underlying classification learning, working memory and exploration of rewarded spatial locations and explore oscillatory responses following stimulation of the target regions. These experimental paradigms will be conducted on the first day after electrode implantation.