Preservation of neurotrophin expression in microglia that migrate into the gerbil's brain across the blood–brain barrier

Microglia isolated from a mixed glial culture drawn from neonatal Mongolian gerbils were demonstrated to produce high amounts of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF). The gerbil microglia retained the capability to migrate into the brain parenchyma after intra-arterial injection. We found that exogenously migrated microglia retained their BDNF and GDNF productive ability and expressed large amounts of BDNF and GDNF in damaged brain areas which suggests microglia's role as a protectant of damaged neurons. Since peripherally injected microglia exhibit specific affinity for areas of neural damage within the brain, we suggest that microglia are possible tools for cell therapy of brain damage.