Fig. 1

Workflow to collect fresh brain material during DBS surgery. a DBS leads were implanted to treat movement disorders in neurosurgical operation at Operative Care Unit, Oulu University Hospital. The tissue samples for LC–MS were collected from the guide tubes, which protruded through the brain tissue to reach the target area and therefore contained tissue material from different brain regions (e.g., cortex and white matter). The samples for RNA sequencing were collected from the recording microelectrodes targeted to the subthalamic nucleus (STN) or globus pallidus interna (GPi). b An image showing how the guide tubes (grey and green thick lines) passed through brain tissue, with the most distal end 10 mm from the planned target. c In contrast, the microelectrodes (thin grey lines) travelled inside the guide tube, and they touched brain tissue only in the STN (green area) and GPi (blue area). To help with anatomical orientation, other brain structures are marked, including the thalamus (dark transparent green), substantia nigra (yellow), red nucleus (red), ansa lenticularis (dark white) and globus pallidus externa (transparent turquoise)