松果体的神经支配

THE INNERVATION OF PINEAL BODY

电镜观察松果体实质,证明充满联合神经分支的薄层有神经纤维,这些纤维与明、暗细胞及神经胶质细胞的胞体和突起紧密相贴。接触点,胞膜增厚,髓鞘内主致密线消失,周期间线空隙加宽,出现施兰氏切迹样结构。无髓交感神经纤维终末膨大,含致密中心小泡,多分布于松果体细胞旁及血管周。本文阐明松果体系由联合神经及交感神经双重支配。

The purpose of this study was for observation of the innervation of pineal gland by using ultrathin section and freeze-etching technique in the rat.Numerous profiles of myelinated nerve fibres were found in the parenchyma of pineal gland,some of them ran parallel to the pinealocytes and were in close contact with them.In the region of contact,the plasma membrane of pinealoeyte showed thickening,myelin sheath of nerve fibers disappeared,the dense-lines were lost and the intraperiod lines separated by large spaces which were filled with electron-lucent substance.The axcns gave rise to processes toward the myelin sheath,so that the neurotransmitter might be permeated through the myelin sheath and reach the pinealocytes.The myelinated nerve fibres came from commissural fibres.So that it was suggested that the commissural fibres might promote the activity of the pinealoeytes and were the main nerve supply for the pineal gland.The terminals of unmyelinated nerve fibres contained some dense-core vesicles,and were distributed in the perivaseular space and among the pinealocytes.The endings of these nerve fibres contacted with pinealocytes and formed synapses with thickened presynaptic and postsynaptic membranes and some clear synaptic vesicles.The pinealocytes could be divided into light and dark cells.The latter contained dense nucleus,numerous free ribosomes,mitochondria,with dense matrix and few rough endoplasmic reticum(rER).The Golgi apparatus were poorly developed.The former had echromatic nucleus with prominent nucleolus,large amount of rER and mitochondria.The Gologi complex well developed.Sometime there might be a lot of dense secretory granules in the cytoplasm.There were some parallely arranged microfilamentes and microtubules in their processes.The two types of cells might be one and the same,but presented differently in different activity state.