大鼠内侧杏仁核的性双形性和向内侧视前区直接投射的研究

SEX DIMORPHISM IN THE MEDIAL AMYGDALOID NUCLEUS AND A STUDY ON THE DIRECT PROJECTIONS FROM THE RAT MEDIAL AMYGDALOID NUCLEUS TO THE MEDIAL PREOPTIC AREA

本文将内侧杏仁核分为5个亚区：即前背亚区、前腹亚区、中背亚区、后背亚区和后腹亚区。细胞构筑定量分析结果表明;雄性大鼠内侧杏仁核的吻尾长度（1.440mm）、体积（0.6485mm3）、细胞总数（50421个）均显著大于雌性（吻尾长度为1.320mm，体积为0.5326mm3，细胞总数为43922个）。并且证明内侧杏仁核的5个亚区中.雄性大鼠后背亚区的吻尾长度（0.510mm）、体积（0.1519mm3）、细胞总数（13331个）都显著地大于雌性（吻尾长度为0.375mm、体积为0.0774mm3、细胞总数为8655个），而其它亚区无上述性别差异。另外，雄性大鼠内侧杏仁核及其后背亚区和后腹亚区的细胞密度小于雌性。上述性别差异均具有统计学意义。这些结果表明内侧杏仁核具有性双形性，且此性双形性主要表现在后背亚区。将HRP注入一侧内侧视前区，在同侧内侧杏仁核各亚区内标记细胞的平均数及其占内侧杏仁核内标记细胞总平均数的百分比为：后背亚区为107.4个，占58％;后瓜亚区为42.1个，占21.2％;前背亚区为16.毛个，占8.8％;前腹亚区为13.6个，占6.7％;中背亚区为9.6个，占5.3％。进一步提示后背亚区可能是内侧杏仁核与性功能有关的主要功能部位。

The medial amygdaliod nucleus (MA) was divided into five subdivisions, which was termed the anterodorsal subtlivision (AD), anteroventral subdivision (AV), intermediodorsal subdivision (ID), posterodorsal subdivision (PD) and posteroventral subdivision (PV). The length, volume and total cell number of MA in the male rats (1. 440 mm. 0. 6485 mm3, 50421 respectively ) were significantly greater than those in the female rats (1. 320 mm, 0. 5326 mm3, 43922 respectively), and the length, volume and total cell number of the PD in the male rats (1. 510 mm, 0. 1519 mm3. 13331 respectively) were significantly greater than those in the female rats (0. 375 mm, 0. 0774 mm3, 8655 respectively), and the sexual differences in the PD was greater than those in the MA in the female rats. Besides, The cell density of the MA, PD, PV in the fenule rats was significantly lower than that in the male rats respectively. After injection of HRP into the medial amygdaloid nucleus, the mean number of labeled cells in subdivisions of the unilateral MA and its percentage to the mean total number of labeled cells in the unilateral MA were: PD, 107. 4, 58. 0%; PV, 42. 1. 21. 2%; AD. 16. 4, 8. 8%; AV. 13. 6, 6. 7%; ID, 9. 6, 5. 3%. The results indicated that the MA is sexual dimorphic and its sexual dimorphism was mainly present in the PD, and it was suggested that the PD was probably the main functional division involved in male sexual behavior in the MA.