Baldino F, Wolfson B
Brain Res. 1985 Jan 28;325(1-2):161-70. doi: 10.1016/0006-8993(85)90312-9.
This study examines the effects of neurotensin (NT) on single neurons in explants of the preoptic-anterior hypothalamus (POAH) in vitro. Standard in vitro electrophysiological techniques were employed. Cultures were prepared from newborn rats and maintained in roller tubes for 3-4 weeks. NT was administered either through the superfusion fluid or via micropressure ejection (0.5-10 psi). Pressure ejection of NT produced a consistent, dose-related, excitatory effect on 71% of the cells studied. The remaining cells were either unresponsive to NT or inhibited by it. In addition, the excitatory effects of microiontophoretically applied glutamate (10-100 nA) were markedly enhanced by NT applied at concentrations that did not alter spontaneous rate. The effects of NT at higher concentrations were additive with glutamate. The effects of NT persisted in Ca2+-free medium when synaptic activity was suppressed. These data indicate that NT exerts a potent excitatory effect on single neurons in the POAH in vitro. Moreover, this effect proved to be additive with that of glutamate. The persistence of these effects in Ca2+-free medium suggests that the actions of NT are postsynaptic in nature.
本研究在体外考察了神经降压素（NT）对视前区 - 下丘脑前部（POAH）外植体中单个神经元的作用。采用了标准的体外电生理技术。从新生大鼠制备培养物，并在滚瓶中培养3 - 4周。NT通过灌流液给药或通过微压喷射（0.5 - 10磅力/平方英寸）给药。NT的压力喷射对71%的研究细胞产生了一致的、剂量相关的兴奋作用。其余细胞要么对NT无反应，要么被其抑制。此外，在不改变自发频率的浓度下施加NT，可显著增强微量离子导入施加的谷氨酸（10 - 100纳安）的兴奋作用。较高浓度的NT的作用与谷氨酸具有相加性。当突触活动被抑制时，NT的作用在无钙培养基中持续存在。这些数据表明，NT在体外对视前区 - 下丘脑前部的单个神经元发挥强大的兴奋作用。此外，这种作用被证明与谷氨酸的作用具有相加性。这些作用在无钙培养基中的持续存在表明，NT的作用本质上是突触后的。
