Figure 3. Relationship between PGP9.5-positive nerve trunks (green) and ICs (red) in the rumen MP with age. Several ICs surrounding a nerve trunk formed a ring-boundary layer, while most ICs interlaced with PGP9.5-positive NFs in the internal nerve trunks. The ICs ring-boundary layer tends to be seamless and gradually closer to the nerve trunk. (Bar =10 μm a–i.)