圆圃棘口吸虫神经系统的乙酰胆碱酯酶定位

Localization of Acetylcholinesterase in the Nervous Systemof Echinostoma Hortense

应用乙酰胆碱酯酶组织化学方法对圆圃棘口吸虫成虫神经系统进行整体定位染色观察，结果显示虫体神经系统呈左右对称排列，中枢神经节位于咽上方的两侧，由粗大的神经连合相连。从中枢神经节向前伸出前背、前腹和前侧３对神经干，并分出细支分布于口吸盘；向后伸出后背、后腹和后侧３对神经干。其中以后腹神经干最为粗大，从中枢神经节中部向体后端伸出，至虫体后部逐渐变细，约在肠支末端稍上方，每条后腹神经干又分成内外两侧支。内侧支与对侧内侧支汇合，并发出细支下行，与后背神经干的分支及许多横向神经纤维在排泄囊处相连，形成螺旋状神经网。而外侧支继续下行，与后侧神经汇合后发出许多细支，在排泄孔周围与内侧的分支连接形成环状神经网。另外，后腹神经干在下行至腹吸盘水平时，分出一对分支沿腹吸盘形成一较粗的神经环。在后３对纵行神经干间，又有许多横向神经联系将其互相连接成神经网。

The nervous system of Echinostoma hortense was studied histochemically with acetylthiocholine iodide The central ganglia situates postero-dorsally to the pharynx and are connected by a transverse commissure. From the central ganglia, three pairs of nerves proceed cephalad. They are the antero-dorsal, antero-ventral and antero-lateral nerves. The delicate branches from the three pairs of anterio nerves contribute to the circum-oral complicate nerve network located in the oral sucker. The post-cephalic longitudinai nerves consist of 3 pairs of nerve cords, nemely, postero-dorsal, postero-ventral and postero-lateral. The postero-ventral ones are a pair of very long nerves, the most prominent in the nervous system.They run posteriorly parallel to each other till they reach the end where they give off two nervous branches, the external and the internal branches. The laters link each other and then branch off continually going down. When they reach the exeretory bladder, they join the postero-dorsal nerves forming the spiral nerve network. The external ones,besides uniting each other, connect the branches of the postero-lateral nerves while they are descending and then form a circum network surrounding the excretory pore. The branches from the postero-ventral nerves spread into the ventral sucker forming the network of ventral sucker and form the circum-ventral ring located in the ventral sucker. All the posterior nerve cords are joined with each other by a number of thin transverse connectives throughout their course,the connectives in turn are further connected to one another by some still thinner longitudinal connectives forming a complicated nerve network.