Davis M D, Kilts C D
Life Sci. 1987 May 11;40(19):1869-74. doi: 10.1016/0024-3205(87)90044-0.
Excised blocks of brain tissue encompassing the hypothalamic periventricular nucleus, arcuate nucleus, infundibular stalk and attached pituitary neurointermediate lobe (NIL) were obtained from rats and perifused in vitro. The intact tuberohypophyseal dopaminergic pathway projecting from cell bodies in the hypothalamus to terminations in the pars intermedia and posterior lobes was thus isolated. An electrode placed in the explant delivered electrical pulses at various frequencies to hypothalamic targets. Products released in the immediate vicinity of the NIL were continuously collected and assayed for dopamine and serotonin content. Electrical stimulation of the arcuate nucleus from 1.0 - 10.0 Hz produced a frequency-dependent increase in dopamine, but not serotonin, release from the NIL. Stimulation of the infundibular stalk, however, elevated the release of both neurotransmitters. Addition of neurotensin (0.001 - 1.0 microM) to the bathing media produced a concentration-dependent increase in dopamine, but not serotonin, release. These experiments demonstrate the utility of the tuberohypophyseal explant as a model for use in the study of dopaminergic neuronal function in this neuroendocrine axis.
从大鼠获取包含下丘脑室周核、弓状核、漏斗柄及附着的垂体神经中间叶（NIL）的脑组织结构块，并进行体外灌流。这样就分离出了从下丘脑细胞体投射至中间部和后叶终末的完整结节垂体多巴胺能通路。置于外植体中的电极以不同频率向下丘脑靶点传递电脉冲。在NIL紧邻区域释放的产物被连续收集，并检测多巴胺和血清素含量。从1.0 - 10.0 Hz对弓状核进行电刺激会使NIL中多巴胺释放呈频率依赖性增加，但血清素释放无此现象。然而，对漏斗柄进行刺激会提高两种神经递质的释放。向灌流液中添加神经降压素（0.001 - 1.0 microM）会使多巴胺释放呈浓度依赖性增加，但血清素释放无此现象。这些实验证明了结节垂体外植体作为该神经内分泌轴中多巴胺能神经元功能研究模型的实用性。
