Rabbit immunoglobulin G (IgG) penetration into the frontal lobe parenchyma and thoracolumbar spinal cord in control, EAE, and EAE +PTx icv (n = 7/group).

Normal +IgG: age-controlled normal mice without EAE receiving a single i.p. injection of rabbit IgG (100 µg/mouse). 7 days EAE: EAE mice on day 7 post immunization; no penetration of rabbit IgG observed in the brain or spinal cord. 14 days EAE: EAE mice on day 14; marked penetration of rabbit IgG noted in both brain and spinal cord. 7 days EAE +PTx: EAE +PTx icv mice on day 7 post immunization; marked penetration of the brain, but no penetration of the spinal cord. 14 days EAE +PTx: EAE +PTx icv mice on day 14 post immunization, continued evidence of brain penetration, no penetration of the spinal cord. Note the dramatic opening of the BBB on Days 7 in EAE +PTx icv group relative to EAE on day 7.