Role of Macrophages in Peripheral Nerve Regeneration
When Segments of autologous peroneal nerve of adult Wistar rats were transplanted into Millipore diffusion Chambers of 0.2 μm pore sizes and then implanted into the peritoneal cavity the myelin sheaths persisted for at least 3 weeks. This method eliminated the access of nonresident cells to the transplant but allowed excellent survival of de-nervated sheath cells within the nerve segment (1). In contrast, in diffusion Chambers of 5.0 μm pore size, which allowed penetration of nonresident cells, myelin was removed at a time-course similar to Wallerian degeneration in situ. The predominant cell type migrating through the 5 μm membrane was the macrophage. By means of a novel diffusionchamber cell-trap we were able to capture a large population of macrophages accumulating in the trap Chamber within 1 week after transplantation (2).