A quantitative study of cerebrovascular variation in inbred mice.

The arteries of the base of the mouse brain were examined after perfusion with India ink. A qualitative difference exists between inbred mice of three strains (C57BL/6J, 129/J and BALB/cCF) on the one hand, and genetically defined heterogeneous mice on the other; the latter consistently show anomalies similar to those previously described in genetically undefined rodents, whereas inbred mice do not. A quantitative morphometric analysis of the Circle of Willis of inbred mice was undertaken. The results of this analysis are consistent with the notion that the differences in shape between the circles of Willis of different strains of inbred mice are due to additive genetic variation between these strains.