Communication of the intracranial space with sphenoid bone marrow in mice.

Tritiated thymidine and Ehrlich ascites tumour cells were injected intrathecally in adult Balb/c mice. Thymidine penetrated easily into the sphenoid bone marrow, where it labelled numerous leukocytes. The microvessel wall constituted a partly penetrable barrier against the infiltration of Ehrlich ascites tumour cells from arachnoid space into the bone marrow.

Cell proliferation in the germinal layer of the lateral brain ventricles in normal adult mice and under some experimental conditions.

Histological and autoradiographic studies revealed mitotic activity in the subependymal germinal layer in the brains of adult mice. The number of mitoses observed was higher in animals subjected to administration of haematoporphyrin and selenourea.