Otake K, Ruggiero D A, Nakamura Y
Department of Anatomy, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Brain Res. 1995 Oct 30;697(1-2):17-26. doi: 10.1016/0006-8993(95)00749-g.
The paraventricular thalamic nucleus (PVT) lies in a pivotal position between the sensorium and a neural network involved in viscerolimbic integration. The aim of this study was to identify pathways used by adrenergic afferents to influence the outflow of the PVT. Potential disynaptic adrenergic projections to the PVT were investigated in chloral hydrate-anesthetized male Sprague-Dawley rats. PVT afferents were retrogradely labeled with cholera toxin B subunit on tissues processed with phenylethanolamine N-methyltransferase (PNMT) immunohistochemistry for displaying putative adrenergic innervation. In several regions of subcortical forebrain, PNMT-immunoreactive terminal-like varicosities were found to be closely associated with the soma and proximal dendritic segments of neurons retrogradely labeled from the PVT. These cell groups formed two topographically organized projection systems. The lateral telencephalic system was composed of a cell continuum formed by the central nucleus of amygdala, sublenticular substantia innominata and bed nucleus of the stria terminalis. The medial diencephalic system included the lateral hypothalamic area, perifornical nucleus, dorsomedial and periventricular hypothalamic nuclei. Adrenergic neurons in the medulla oblongata may modulate the activity of midline thalamic circuit neurons implicated in behavior.
室旁丘脑核（PVT）位于感觉中枢与参与内脏边缘整合的神经网络之间的关键位置。本研究的目的是确定肾上腺素能传入神经影响PVT传出的途径。在水合氯醛麻醉的雄性Sprague-Dawley大鼠中研究了对PVT的潜在双突触肾上腺素能投射。在用苯乙醇胺N-甲基转移酶（PNMT）免疫组织化学处理的组织上，用霍乱毒素B亚基对PVT传入神经进行逆行标记，以显示假定的肾上腺素能神经支配。在皮质下前脑的几个区域，发现PNMT免疫反应性终末样曲张体与从PVT逆行标记的神经元的胞体和近端树突段密切相关。这些细胞群形成了两个按拓扑组织的投射系统。外侧端脑系统由杏仁核中央核、豆状核下无名质和终纹床核形成的细胞连续体组成。内侧间脑系统包括下丘脑外侧区、穹窿周核、下丘脑背内侧核和室周核。延髓中的肾上腺素能神经元可能调节与行为有关的中线丘脑回路神经元的活动。
