• 1 January 1978
    • journal article
    • research article
    • Vol. 125  (JAN) , 101-106
Abstract
To clarify the origin of brain macrophages, circulating leukocytes were labeled by i.v. injection with carbon particles. At 24 and 48 h after injection, carbon-labeled cells appeared in the corpus callosum and cerebral cortex of newborn rats. No carbon-labeled cells were seen in the brain tissue of young and adult rats. Some of the brain macrophages are of a hematological origin. Infiltration of blood elements into the brain occurs in the early postnatal period.