Prenatal development of the hippocampus in two strains of inbred mice

In this paper we present some morphological observations on the morphogenesis of the hippocampus in two inbred strains of mice, C57BL/6J (C57) and DBA/2J (DBA), from day 16 (E16) to day 17 (E17) of prenatal life. At E16 some differences in the histoarchitecture of the hippocampal anlage begin to be detectable. At E17 the differences become more relevant, particularly those concerning the lamination pattern. The more relevant differences concern the differentiation of the pyramidal layer, which appears well defined in C57 mice, while in DBA mice there is no clearcut delimitation between the pyramidal layer and the intermediate zone, where numerous migrating neurons are present. These observations may be interpreted in terms of different migration rates for the neurons in the two strains.