Hatton Glenn I, Wang Yu-Feng
Department of Cell Biology and Neuroscience, University of California, Riverside, CA, USA.
Prog Brain Res. 2008;170:155-66. doi: 10.1016/S0079-6123(08)00414-7.
One of the more interesting and complex phenomena involving neurohypophysial hormones is the milk ejection reflex and the events surrounding it. Accordingly, many investigations over the years have taken up the challenge of elucidating its myriad aspects. Much has been learned from in vivo preparations about the sequence of events that so regularly occurs: important priming by maternal behaviours, the intermittent rhythms, gating of bursting, synchrony of the oxytocin (OXT) neuronal bursts emitted intermittently in response to the continuous suckling of the young and the factors that influence the amplitude of the bursts/milk ejections (e.g. number of suckling pups). In vivo electrophysiological studies are constrained by the infeasibility of routinely recording transmembrane events and, therefore, cannot offer detailed membrane and/or synaptic analyses. Recent studies have developed an in vitro model of OXT neuronal bursting that has allowed more mechanistic analyses of these bursts as well as factors involved in their generation and structure. Here we review many of the cellular and molecular mechanisms that have been shown to underlie the milk ejection bursts, as revealed by in vitro analyses.
涉及神经垂体激素的一个较为有趣且复杂的现象是喷乳反射及其周围的一系列事件。因此，多年来许多研究都在努力阐明其众多方面。从体内实验中我们已经了解到了经常发生的一系列事件：母体行为的重要启动作用、间歇性节律、脉冲发放的门控、因幼崽持续吮乳而间歇性发放的催产素（OXT）神经元脉冲的同步性，以及影响脉冲幅度/喷乳的因素（例如吮乳幼崽的数量）。体内电生理研究受到常规记录跨膜事件不可行性的限制，因此无法提供详细的膜和/或突触分析。最近的研究建立了一个体外催产素神经元脉冲发放模型，这使得对这些脉冲以及参与其产生和结构的因素能够进行更多的机制分析。在此，我们回顾体外分析所揭示的许多已被证明是喷乳脉冲发放基础的细胞和分子机制。
