Neuronal uptake of plasma proteins in brain contusions. An immunohistochemical study

Twenty-five cases of cerebral contusions of various age were examined immunohistochemically for neuronal uptake of albumin and fibrinogen. The neurons in the damaged areas were heavily stained in all cases, even in those of only a few minutes' survival, and they remained positive for serum proteins until they disappeared from the lesions. In hematoxylin and eosin-stained sections, neuronal changes were observed from the first minutes after the lesion but they were indistinguishable from the shrunken "dark" neurons that occur as artifacts in poorly fixed material. However, in contrast to the artificially changed cells, the truly damaged ones took up serum proteins. It is concluded that staining with antisera against serum proteins may serve as early markers for neuronal injury before reliable histological changes have developed.