Connections from the subfornical organ to the oxytocin and vasopressin systems in the lactating rat. A study using electrical stimulations, lesions and electrophysiological recordings.
Connections from the subfornical organ to the oxytocin and vasopressin systems in the lactating rat. A study using electrical stimulations, lesions and electrophysiological recordings.
复制标题
哺乳大鼠穹窿下器官与催产素和加压素系统的连接。
DOI：
10.1016/0006-8993(94)01278-p
复制
发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Poulain,DA
中科院分区：
文献类型：
--
作者：
Boudaba,C;Tasker,JG;Poulain,DA
内侧间隔区参与下丘脑大细胞神经分泌细胞的控制，特别是分泌催产素的神经元的调节。本研究调查了该内侧间隔通路起源于穹窿下器官的假设。对穹窿下器官或内侧隔膜进行短暂的电刺激都会引起乳房内压力的短暂升高，相当于静脉注射引起的压力。注射1mU催产素。最佳频率为 5-20 Hz，持续 5-10 秒。长时间的刺激在开始时也会引起单一的瞬时反应，类似于短暂刺激所引起的反应。细胞外记录是由视上核的神经分泌细胞进行的，通过神经柄的逆向刺激来识别，并根据它们在哺乳引起的反射性喷乳时的反应进一步分为加压素能和催产素能。穹窿下器官的单脉冲刺激很少产生兴奋，但短刺激序列会在大多数催产素能和加压素能神经元中引起大量兴奋。为了进一步描绘从穹窿下器官到大细胞神经元的通路，将刺激与内侧前脑的各种损伤相结合。穹窿下器官的刺激作用在紧邻该器官喙部的切片后被消除，并且在大多数情况下在内侧隔膜损伤后被消除。在实验前一周穹窿下器官受损后，内侧隔膜的刺激不再产生作用，这段时间足以使穹窿下传出神经退化。这项研究表明，从内侧间隔区到下丘脑的催产素和加压素分泌神经元的兴奋性传入输入起源于穹窿下器官。该输入不参与喷乳反射的主要传入控制，因为穹窿下器官和内侧隔膜的损伤对反射没有影响。因此，表明穹窿下对催产素和加压素细胞的输入进行干预，以促进两种激素在非生殖功能中的协同作用。
The medial septal area has been implicated in the control of the magnocellular neurosecretory cells of the hypothalamus, and in particular, in the regulation of neurons secreting oxytocin. The present study investigated the hypothesis that this medial septal pathway originates in the subfornical organ. Brief electrical stimulation of the subfornical organ or the medial septum both evoked a transient rise in intramammary pressure equivalent to that caused by an i.v. injection of 1 mU oxytocin. The optimal frequency was 5–20 Hz for 5–10 s. Prolonged stimulation also elicited at its onset a single transient response, similar to that evoked by brief stimulation. Extracellular recordings were made from neurosecretory cells of the supraoptic nucleus identified by antidromic stimulation of the neural stalk and further classified as vasopressinergic and oxytocinergic by their reaction at the time of reflex milk ejection induced by suckling. Single-pulse stimulation of the subfornical organ rarely produced excitation, but short trains of stimuli evoked a large excitation in most oxytocinergic and vasopressinergic neurons. To delineate further the pathway from the subfornical organ to the magnocellular neurons, stimulations were combined with various lesions of the medial forebrain. The effects of stimulation of the subfornical organ were abolished after a section immediately rostral to the organ, and in most cases after lesion of the medial septum. Stimulation of the medial septum no longer had an effect after the subfornical organ had been lesioned a week prior to experiments, a period sufficient to allow degeneration of subfornical efferents. This study shows that the excitatory afferent input to the oxytocin and vasopressin-secreting neurons of the hypothalamus from the medial septal area originates in the subfornical organ. This input is not involved in the main afferent control of the milk ejection reflex since lesions of the subfornical organ and of the medial septum had no effect on the reflex. It is suggested, therefore, that the subfornical input to both oxytocin and vasopressin cells intervenes to facilitate synergistic action of both hormones in non-reproductive functions.