West M J, Andersen A H
Brain Res. 1980 Dec;2(3):317-48. doi: 10.1016/0165-0173(80)90012-0.
The volumes of the hilus, stratum granulosum, stratum moleculare and the zones of the stratum moleculare corresponding to the terminal fields of the perforant paths and the ipsilateral-commissural projections have been estimated in the area dentata of Wistar rats and DBA/2J mice, stained according to the Timm technique. The density of granule cells in the stratum granulosum and synaptic contacts in the stratum moleculare have been estimated from low power electron micrographs using stereological techniques. The volume and density parameters have been used to calculate the total number of granule cells and synaptic contacts in the fasciae dentatae of these two species. It is concluded that the number of synaptic contacts is proportional to the volume of the fascia dentata while the number of granule cells is proportional to the surface area of the fascia dentata and that the fasciae dentatae in these two species are isometric forms. The implications of these relationships are discussed with regard to the effect of the size of the fascia dentata on information processing in this structure. A significant difference existed between the ratio of the volumes of the hila and the ratio of the volumes of the fasciae dentatae in the two species studied. However, the volume of the deep zone of the stratum moleculare fasciae dentatae, the terminal zone of the hilar afferents was proportional to the volume of the hilus. The same density of synaptic contacts in the deep zone of the strata molecularia of both species, therefore, indicates a proportionality between the volume of the hilus and the number of synaptic contacts made by the hilar afferents. These observations are discussed with respect to the manner by which the maintenance of the observed proportionalities and the relative differences in the size and number of neurons in the subregions of the area dentata may be involved in the modification of the form and function of this region during phylogenesis.
运用Timm技术染色，对Wistar大鼠和DBA/2J小鼠齿状回区域的门区、颗粒层、分子层以及与穿通通路终末野和同侧连合投射相对应的分子层区域的体积进行了估计。利用体视学技术，从低倍电子显微镜照片中估计了颗粒层中颗粒细胞的密度以及分子层中的突触接触。这些体积和密度参数被用于计算这两个物种齿状回中颗粒细胞和突触接触的总数。得出的结论是，突触接触的数量与齿状回的体积成正比，而颗粒细胞的数量与齿状回的表面积成正比，并且这两个物种的齿状回是等比形式。讨论了这些关系对于齿状回大小对该结构信息处理的影响。在所研究的两个物种中，门区体积比和齿状回体积比之间存在显著差异。然而，齿状回分子层深层区域（门区传入纤维的终末区）的体积与门区的体积成正比。因此，两个物种分子层深层区域相同的突触接触密度表明门区体积与门区传入纤维形成的突触接触数量之间存在比例关系。讨论了这些观察结果与在系统发育过程中齿状回亚区域中观察到的比例关系的维持以及神经元大小和数量的相对差异可能参与该区域形态和功能改变的方式。
