The Effect of in Vitro Culture and Embryo Transfer on Neuronal Density and Neurogenesis in the Brains of C57BL/6J Mice

Abstract—This research is aimed at determining the long-term effects of in vitro culture (IVC) and embryo transfer (ET) on neonatal development of offspring, as well as on adult hippocampal neuronal densities and hippocampal neurogenesis in C57BL/6J mice. Offspring of naturally born C57BL/6J mice (C57BL group) were compared with C57BL/6J mice born as a result of the IVC combined with ET to C57BL/6J recipient females (ET-C57BL group). At the age of 3 months, no group differences were observed in the body weight and brain-to-body ratio, although sex differences in these variables were observed. The offspring of both sexes born after IVC–ET exhibited a lower level of neurogenesis in the dentate gyrus (DG) of the hippocampus compared to the control C57BL group. Thus, IVC and ET exerted no major effects on body and brain weight in offspring, but affected hippocampal neurogenesis in the adult offspring of both sexes. As well, the number of pyramidal neurons in the CA3 area of hippocampus was lower in female offspring of the ET-C57BL group.