Hrabovszky E, Liposits Z
Department of Anatomy, University Medical School, Pécs, Hungary.
Neurosci Lett. 1994 Dec 5;182(2):143-6. doi: 10.1016/0304-3940(94)90783-8.
Tuberoinfundibular dopaminergic (TIDA) neurons, which represent the final common pathway in the inhibitory neuronal control of prolactin (PRL) secretion, are regulated by synaptic input from various transmitter systems. Because adrenergic receptors at hypothalamic sites were implicated in the central regulation of lactotrophs, we hypothesized that a synaptic communication might exist between adrenergic pathways ascending from the brain stem and the TIDA system. Polyclonal antisera directed towards phenylethanolamine N-methyltransferase (PNMT) and tyrosine hydroxylase (TH), biosynthetic enzymes of catecholamines, were used for the simultaneous immunocytochemical detection of adrenergic fibers and TIDA neurons, respectively, in Vibratome sections of the rat hypothalamus. By the light microscopic evaluation of double-immunostained sections, PNMT-immunoreactive (IR) axon varicosities were localized in juxtaposition to TH-IR cell bodies and dendrites in the arcuate nucleus (AN) which contains perikarya and dendrites of TIDA neurons. The ultrastructural analysis of contacts provided firm evidence for the occurrence of synaptic interactions between the adrenergic and TIDA neuronal systems. These morphological findings show that adrenergic neurons are involved in the afferent regulation of the TIDA system and indicate a putative pathway of central adrenergic effects upon PRL secretion.
结节漏斗多巴胺能（TIDA）神经元是催乳素（PRL）分泌抑制性神经控制的最终共同通路，受多种递质系统的突触输入调节。由于下丘脑部位的肾上腺素能受体与促乳素细胞的中枢调节有关，我们推测脑干上行的肾上腺素能通路与TIDA系统之间可能存在突触联系。针对儿茶酚胺生物合成酶苯乙醇胺N -甲基转移酶（PNMT）和酪氨酸羟化酶（TH）的多克隆抗血清，分别用于在大鼠下丘脑振动切片中同时免疫细胞化学检测肾上腺素能纤维和TIDA神经元。通过对双重免疫染色切片的光学显微镜评估，PNMT免疫反应性（IR）轴突膨体定位于含有TIDA神经元胞体和树突的弓状核（AN）中TH - IR细胞体和树突附近。接触的超微结构分析为肾上腺素能和TIDA神经元系统之间发生突触相互作用提供了确凿证据。这些形态学发现表明肾上腺素能神经元参与TIDA系统的传入调节，并提示了中枢肾上腺素能对PRL分泌作用的假定途径。
