Ohbuchi Toyoaki, Haam Juhee, Tasker Jeffrey G
Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA.
Interdiscip Inf Sci. 2015;21(3):225-234. doi: 10.4036/iis.2015.B.07.
Vasopressin is a peptide hormone secreted from the posterior pituitary gland in response to various physiological and/or pathological stimuli, including changes in body fluid volume and osmolality and stress exposure. Vasopressin secretion is controlled by the electrical activity of the vasopressinergic magnocellular neurosecretory cells located in the hypothalamic supraoptic nucleus and paraventricular nucleus. Vasopressin release can occur somatodendritically in the hypothalamus or at the level of pituitary axon terminals. The electrical activity of the vasopressin neurons assumes specific patterns of electrical discharge that are under the control of several factors, including the intrinsic properties of the neuronal membrane and synaptic and hormonal inputs. It is increasingly clear that glial cells perform critical signaling functions that contribute to signal transmission in neural circuits. Astrocytes contribute to neuronal signaling by regulating synaptic and extrasynaptic neurotransmission, as well as by mediating bidirectional neuronal-glial transmission. We recently discovered a novel form of neuronal-glial signaling that exploits the full spatial domain of astrocytes to transmit dendritic retrograde signals from vasopressin neurons to distal upstream neuronal targets. This retrograde trans-neuronal-glial transmission allows the vasopressin neurons to regulate their synaptic inputs by controlling upstream presynaptic neuron firing, thus providing a powerful means of controlling hormonal output.
血管加压素是一种肽类激素，由垂体后叶分泌，以响应各种生理和/或病理刺激，包括体液量和渗透压的变化以及应激暴露。血管加压素的分泌受位于下丘脑视上核和室旁核的血管加压素能大细胞神经分泌细胞的电活动控制。血管加压素的释放可在下丘脑的树突体部位或垂体轴突终末水平发生。血管加压素神经元的电活动呈现特定的放电模式，这些模式受多种因素控制，包括神经元膜的内在特性以及突触和激素输入。越来越清楚的是，胶质细胞执行关键的信号传导功能，有助于神经回路中的信号传递。星形胶质细胞通过调节突触和突触外神经传递以及介导双向神经元 - 胶质细胞传递来促进神经元信号传导。我们最近发现了一种新型的神经元 - 胶质细胞信号传导形式，它利用星形胶质细胞的整个空间域将树突逆行信号从血管加压素神经元传递到远端上游神经元靶点。这种逆行跨神经元 - 胶质细胞传递使血管加压素神经元能够通过控制上游突触前神经元的放电来调节其突触输入，从而提供了一种控制激素输出的强大手段。
