Australian scientists have discovered sex-dependent differences in the volume of some structures of the hippocampus. It turned out that in men, for example, more parasubiculum, presbyterum, fimbria and hippocampal furrow, but women a little more hippocampal tail. Differences were observed regardless of the total hippocampal volume, which should be considered in future studies of anatomical structures, write the scientists in the journal NeuroImage.
Studies conducted on large samples of people point to the lack of significant structural differences that would reliably distinguish a female brain from the male. In spite of this, some anatomical features of the brain still depends on the sex, but most often this dependence is due to the fact that the volume of the male brain is on average larger than the female brain.
However, not all studies take into account the differences in the overall brain volume and volume of individual large structures as a side variable, so consensus on the absence or presence of structural differences in some areas in the female and male brain often do not. It concerns, for example, the hippocampus — the part of the brain that plays a major role in the formation and storage of memories. Some studies note the lack of structural differences in male and female hippocampus, while others indicate that some differences still there.
To learn more about the differences in the hippocampus of male and female brain has decided scientists led by Lisa van Eyck (Liza van Eijk) from the University of Queensland. In particular, they focused not on the hippocampus as a holistic structure, and its separate parts. For their study, the scientists collected 1687 MRI scans of the brain of men and women from two population-based samples: one collected for cytogenetics studies, and the second to project the Human Connectome. The researchers compared the 12 regions of the hippocampus of men and women, adjusted either for the total volume of the hippocampus or whole brain.
Scientists have discovered that men have on average more parasubiculum hippocampus (to 6.04 percent) and fimbria (to 8.75 percent). Such differences were observed when adjusted for hippocampal volume, does not depend on the method of comparison, as was also observed in both samples separately. Sample Human Connectome and the joint sample, the researchers also found a greater volume of hippocampal sulcus (to 6.75%) and presbyterum (up 3.08 percent) and a smaller hippocampal tail volume (up 0.23 percent) in men in comparison with women also adjusted the volume of the hippocampus.
Thus, inside the hippocampus in reality there are differences in the volume of individual structures based on gender — and regardless of how the volume of the hippocampus differs in men and women. When adjusted for total brain volume, these differences were not observed: scientists, therefore, said that future research is necessary to examine anatomical differences in the hippocampus, given its total volume, not just the brain but also to take this into account and in studies of functional differences.
Not all studies of sex differences in the brain focus on the structural differences: some consider the distinction functional, and come to rather interesting conclusions. For example, the female brain on average, active men (about ten percent), better with age preserves the youth, and its compensation system more responsive to the behavior aimed at helping others.