Model of lumbar subarachnoid injection of human neurons near the human spinal cord. MRI image of the human spinal cord (a) with a lumbar puncture of the subarachnoid space adjacent to the cord (b), and injection of cells, such as the GABAergic human neuronal hNT. 2.17 cells (c) for pain relief, as delivered by syringe (d). A similar technique has been used in all pre-clinical animal experiments and clinical studies with human chromaffin cell injections for pain.