In degenerative disorders of the spine such as disc herniation, intervertebral discs can affect neural tissue, which may result in pain as demonstrated in both basic science and clinical investigations. Previous A disc herniation model in rats (n=58) was used. The L4 nerve root was exposed to a) nucleus pulposus (3mg), b) notochordal cells (25,000 cells) or c) chondrocyte-like cells (25,000 cells). Four control groups were included: 1) application of nucleus pulposus (3 mg) and mechanical displacement of the spinal nerve complex, 2) sham operated animals, 3) application of cell diluent (50 μl) and 4) naïve animals. Seven days after surgery the L4 nerve roots with their dorsal root ganglion were harvested and prepared for blinded neuropathological examinations using light microscopy.Introduction
Material and method
