How anti-brain antibodies access the bran and alter behavior and cognition

Abstract

Antibodies can target brain antigens but are not harmful to the host unless they enter brain parenchyma. An adult human or mouse has a blood brain barrier that excludes immunoglobulin from entering brain parenchyma. In the adult host, insults to barrier integrity allow IgG to penetrate brain tissue. These insults have regional specificity so that the same antibody can lead to a distinct cognitive or behavioral abnormality depending on the site of blood brain barrier breach.During fetal development there is a period of time when maternal IgG crosses the placenta, and the fetal blood brain barrier is not yet mature. During this time, maternal antibody can have an impact on fetal brain development which may be sex specific and may have long term consequences.Learning to regulate the blood brain barrier and to prevent placental transport of maternal brain-reactive antibodies may be neuroprotective for many conditions.