Kallai Janos, Csathó Arpád, Kövér Ferenc, Makány Tamás, Nemes János, Horváth Krisztina, Kovács Norbert, Manning John T, Nadel Lynn, Nagy Ferenc
Institute of Psychology, University of Pécs, Szigeti u12, H-7624 Pécs, Hungary.
Psychiatry Res. 2005 Nov 30;140(2):199-210. doi: 10.1016/j.pscychresns.2004.05.010.
Atrophy of the left or right side of the hippocampus has been related to cognitive deficits and psychiatric disease. In this study, we examined the correlation between the hippocampal volume laterality index and the relative lengths of the second (index finger) and fourth (ring finger) digits (2D:4D) in healthy female subjects. The 2D:4D ratio is fixed in utero, and the ratio is higher in women than in men. There is evidence that this ratio is an indicator of the intrauterine concentration of testosterone, which influences the development of different regions of the brain. Assessing the volume of different parts of the brain of 40 healthy adult female students by magnetic resonance imaging (MRI), we found that the 2D:4D ratio was associated with an asymmetry in the hippocampal sub-regions. Smaller volume on the left side was found in the posterior part of the hippocampus in females with a low (masculine type) 2D:4D ratio. On the other hand, smaller volume on the left side was found in the middle part of the hippocampus in females with a high (female type) 2D:4D ratio. Thus, the development of the middle and posterior regions of the hippocampal formation may respond in opposite ways to prenatal levels of testosterone. Other brain regions such as the amygdala, the cerebral cortex, the total volume hippocampus, and the head of the hippocampus did not show such a difference.
海马体左侧或右侧萎缩与认知缺陷及精神疾病有关。在本研究中，我们检测了健康女性受试者中海马体体积偏侧指数与第二指（食指）和第四指（无名指）相对长度（2D:4D）之间的相关性。2D:4D比例在子宫内就已固定，女性的该比例高于男性。有证据表明，这一比例是子宫内睾酮浓度的一个指标，而睾酮浓度会影响大脑不同区域的发育。通过磁共振成像（MRI）评估40名健康成年女学生大脑不同部位的体积，我们发现2D:4D比例与海马体亚区域的不对称性有关。2D:4D比例低（男性类型）的女性，其海马体后部左侧体积较小。另一方面，2D:4D比例高（女性类型）的女性，其海马体中部左侧体积较小。因此，海马结构中、后部区域的发育可能对产前睾酮水平有相反的反应。其他脑区，如杏仁核、大脑皮层、海马体总体积以及海马体头部，并未表现出这种差异。
