Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Vic., Australia; Department of Physiology, University of Melbourne, Melbourne, Vic., Australia.
Acta Physiol (Oxf). 2015 May;214(1):8-32. doi: 10.1111/apha.12487. Epub 2015 Apr 1.
Located in the midline anterior wall of the third cerebral ventricle (i.e. the lamina terminalis), the median preoptic nucleus (MnPO) receives a unique set of afferent neural inputs from fore-, mid- and hindbrain. These afferent connections enable it to receive neural signals related to several important aspects of homeostasis. Included in these afferent projections are (i) neural inputs from two adjacent circumventricular organs, the subfornical organ and organum vasculosum laminae terminalis, that respond to hypertonicity, circulating angiotensin II or other humoural factors, (ii) signals from cutaneous warm and cold receptors that are relayed to MnPO, respectively, via different subnuclei in the lateral parabrachial nucleus and (iii) input from the medulla associated with baroreceptor and vagal afferents. These afferent signals reach appropriate neurones within the MnPO that enable relevant neural outputs, both excitatory and inhibitory, to be activated or inhibited. The efferent neural pathways that proceed from the MnPO terminate on (i) neuroendocrine cells in the hypothalamic supraoptic and paraventricular nuclei to regulate vasopressin release, while polysynaptic pathways from MnPO to cortical sites may drive thirst and water intake, (ii) thermoregulatory pathways to the dorsomedial hypothalamic nucleus and medullary raphé to regulate shivering, brown adipose tissue and skin vasoconstriction, (iii) parvocellular neurones in the hypothalamic paraventricular nucleus that drive autonomic pathways influencing cardiovascular function. As well, (iv) other efferent pathways from the MnPO to sites in the ventrolateral pre-optic nucleus, perifornical region of the lateral hypothalamic area and midbrain influence sleep mechanisms.
位于第三脑室（即终板）中线前壁的正中视前核（MnPO）接收来自前脑、中脑和后脑的独特的传入神经输入。这些传入连接使它能够接收与几个重要的内稳态方面相关的神经信号。包括在这些传入投射中的有（i）来自两个相邻的室周器官，即穹窿下器官和终板血管器官的神经输入，它们对高渗性、循环血管紧张素 II 或其他体液因素做出反应，（ii）来自皮肤温觉和冷觉感受器的信号，分别通过外侧臂旁核的不同亚核中继到 MnPO，以及（iii）来自与压力感受器和迷走神经传入相关的延髓的输入。这些传入信号到达 MnPO 内的适当神经元，使相关的神经输出，无论是兴奋性的还是抑制性的，都能够被激活或抑制。从中枢神经系统传出的神经通路终止于（i）下丘脑视上核和室旁核的神经内分泌细胞，以调节血管加压素的释放，而从中枢神经系统传出的多突触通路到皮质部位可能会引起口渴和饮水，（ii）到下丘脑背内侧核和延髓 Raphe 的体温调节途径，以调节颤抖、棕色脂肪组织和皮肤血管收缩，（iii）下丘脑室旁核的小细胞神经元，驱动影响心血管功能的自主神经途径。此外，（iv）MnPO 到腹外侧视前核、下丘脑外侧区的peri 区和中脑的其他传出途径影响睡眠机制。
