Electrophysiological differentiation of oxytocin-and vasopressin-secreting neurones
Electrophysiological differentiation of oxytocin-and vasopressin-secreting neurones
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催产素和加压素分泌神经元的电生理分化
DOI：
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发表时间：
1977
期刊：
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通讯作者：
R. Dyball
中科院分区：
文献类型：
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作者：
D. Poulain;J. Wakerley;R. Dyball
脑室旁神经分泌细胞的逆行鉴定(P.V.)和超光学(S，O.)在乌拉坦麻醉下，记录了哺乳期大鼠在反射性排乳过程中的下丘脑核团。还有大出血。本文对81个P.V.和S O型神经元进行了研究。它们的背景放电频率为-lt；0.1~6.3次/S，有三种不同的活动模式：缓慢不规则(73%)、快速持续(10%)和时相(17%)。有40个单位(49%)表现出与哺乳诱发动作相关的短暂高频放电(30-60个/S)(2-4个S)，这些单位被归类为催产素分泌神经元。其余的细胞此时没有表现出激活，被归类为非M细胞。E.神经元。10个大脑皮层神经元放血(5ml)后，放电频率逐渐加快，最高达3.7±0.7次/S(平均值+S)。大约在抽血后20分钟。因此，动电神经元的放电模式从缓慢的不规则类型转变为快速的连续类型。相比之下，11个非m。用相同程序测试的E.神经元在第4分钟时迅速激活，最高可达6.4±0.6个/S。非m。这些神经元最初是缓慢的不规则类型，先是变得快速连续，后来演变成一种高度特征的相态活动模式，这种模式在mE神经元中从未被诱导过。在血液被替换后，所有的细胞都恢复了原来的激活模式。在一系列平行的实验中，在出血后5分钟和25分钟采集的血浆样本显示，抗利尿活性增加了10倍。脑电活动也略有增加，但并不显著。因此，P.V.和S的神经分泌细胞可能在电物理上分化为两个不同的功能群体：(1)催产素释放神经元，它们在哺乳诱导前表现为高频放电；(2)加压素释放神经元，在出血诱导的加压素释放过程中，采取时相放电模式。我们认为，加压素分泌进入循环的速度在很大程度上取决于加压素神经元相性放电的比例，它们在各时相内的放电频率，以及各时相同步的时间和程度。
Antidromically identified neurosecretory cells of the paraventricular (p. v.) and supraoptic (s. o.) nuclei of the hypothalamus were recorded in lactating rats under urethane anaesthesia during reflex milk ejection (m. e.) and haemorrhage. Eighty one p. v. and s. o. neurones were studied. Their background firing rates ranged from < 0.1 to 6.3 spikes/s and three distinct patterns of activity were encountered: slow irregular (73%), fast continuous (10%) and phasic (17%). Forty units (49%) displayed a brief (2-4 s) high-frequency discharge (30-60 spikes/s) correlated with suckling-induced m. e., and these were classified as m. e. (oxytocin-secreting) neurones. The remainder of the cells showed no activation at this time and were classified as non-m. e. neurones. Ten m. e. neurones tested through haemorrhage (5 ml of blood) showed a gradual acceleration of firing rates, reaching a maximum of 3.7 ± 0.7 spikes/s (mean + s. e.) about 20 min after blood withdrawal. The firing pattern of the m. e. neurones therefore changed from a slow irregular to a fast continuous type. By contrast, 11 non-m. e. neurones tested with the same procedure showed a rapid activation reaching a maximum of 6.4 ±0.6 spikes/s by the fourth minute. Non-m. e. neurones which were initially of the slow irregular type, first became fast continuous and later evolved into a highly characteristic phasic pattern of activity which was never induced in the m. e. neurones. After the blood was replaced, all the cells returned to their original firing pattern. In a parallel series of experiments, plasma samples taken 5 and 25 min after haemorrhage showed a ten-fold elevation in antidiuretic activity. A slight but non-significant increase in m. e. activity was also observed. Thus p. v. and s. o. neurosecretory cells may be electrophysically differentiated into two functionally distinct populations: (1) oxytocin releasing neurones which show a high-frequency discharge before m. e. induced by suckling, and (2) vasopressin-releasing neurones which adopt a phasic pattern of firing during vasopressin release induced by haemorrhage. We suggest that the rate of vasopressin secretion into the circulation largely depends on the proportion of vasopressin neurones firing phasically, their firing rates within the phases and the duration and degree of synchronization of the phases.