Possible morphological bases for synchronisation of neuronal firing in the rat supraoptic nucleus during lactation
Possible morphological bases for synchronisation of neuronal firing in the rat supraoptic nucleus during lactation
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哺乳期间大鼠视上核神经元放电同步的可能形态学基础
DOI：
10.1016/0306-4522(81)90173-1
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发表时间：
1981
期刊：
影响因子：
3.3
通讯作者：
J. Vincent
中科院分区：
文献类型：
--
作者：
D. Theodosis;D. Poulain;J. Vincent
泌乳大鼠视上核和室旁核中含催产素的神经元显示出周期性激活，这导致在每次哺乳引起的反射性排乳之前脉冲式释放激素。这种电活动以全或无的方式发生，并且在两个核团中的整个催产素神经元群体中同步。本报告描述了哺乳动物的视上核的超微结构的变化，这可能是这样的功能synchronization.In正常大鼠的视上核的形态学基础，神经分泌神经元通常由神经元的元素，特别是胶质细胞的过程分开。在罕见的间隔，相邻的神经分泌胞体，树突，被认为是在直接并置。相邻膜之间唯一明显的特化是偶尔的附着板。在哺乳期大鼠的细胞核中，定量分析表明，34%的剖面的神经分泌细胞体彼此直接接触，22%的剖面的树突，5倍的增加，在正常雄性和处女雌性动物中观察到的相应频率。这种接触涉及总测量索马表面膜的10%（对照组为1.5%）。支持贴壁膜的附着板数量也显著增加，单个贴壁的平均尺寸也显著增加。突触前终末在同一切面上与多个突触后元件（索马或树突）接触的发生率也较高，这在正常核中是罕见的现象。没有进一步的增加是显而易见的，在这些同位关系在处女女性和哺乳期大鼠被剥夺了一天的水，一个刺激，增强后叶加压素release.It的假设，结构重组观察到的哺乳动物的细胞核可能导致电之间的相互作用的神经分泌细胞，因此可能是支持的因素之一，在情节释放催产素的神经元活动的同步。
Oxytocin-containing neurones in the supraoptic and paraventricular nuclei of lactating rats display a periodic activation which results in a pulsatile release of hormone before each reflex milk ejection induced by suckling. This electrical activity occurs in an all-or-none fashion and is synchronised in the whole population of oxytocin neurones in both nuclei. The present report describes changes in the ultrastructure of the supraoptic nucleus of lactating animals which may serve as morphological bases for such a functional synchronisation.In the supraoptic nuclei of normal rats, neurosecretory neurones are usually separated by elements of the neuropil, particularly glial processes. At rare intervals, adjacent neurosecretory somata, and dendrites, are seen to be in direct apposition. The only specialisations apparent between the contiguous membranes are occasional attachment plates. In nuclei of lactating rats, quantitative analysis indicated that 34% of profiles of the sectioned neurosecretory cell bodies were in direct contact with each other and 22% with profiles of dendrites, a 5-fold increase over the corresponding frequencies observed in normal male and virgin female animals. Such contacts involved 10% of the total measured soma surface membrane (compared to 1.5% in the controls). The number of attachment plates supporting the apposing membranes also increased significantly as did the mean size of the individual appositions. There was also a higher incidence of presynaptic terminals contacting more than one post-synaptic element (soma or dendrite) in the same plane of section, a rare phenomenon in the normal nucleus. No further increases were evident in these appositional relations in virgin female and lactating rats deprived of water for one day, a stimulus which enhances vasopressin release.It is postulated that the structural reorganisation observed in the nuclei of lactating animals may lead to electrical interactions between the neurosecretory cells and may thus be one of the factors supporting the synchronisation of neuronal activity during the episodic release of oxytocin.